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SmartBall® Inline Free-Swimming Pipeline Inspection Platform

The SmartBall platform is a free-swimming inspection tool used to detect leaks and gas pockets and map pipeline networks. This platform assesses pressurized water and wastewater pipelines in a single deployment, without disrupting regular service. The SmartBall platform provides utilities with pipeline condition data to make informed rehabilitation and management decisions on a pipe-by-pipe basis.

Video

PipeDiver® Inline Free-Swimming Pipeline Condition Assessment Platform

The PipeDiver platform is a free-swimming pipeline condition assessment tool that is easy to deploy and operates while the pipeline remains in service. This tool provides utility owners with pipe wall condition data used to make rehabilitation and management decisions on a pipe-by-pipe basis.

Video

GLWA implements proactive condition assessment on their transmission system

Sue McCormick, CEO for Great Lakes Water Authority, talks about how a proactive condition assessment program on their transmission systems will allow them to significantly reduce the investment needed to improve their system while avoiding breaks and unscheduled repairs that greatly affect their customers.

Video

Helping the city of Houston extend capital dollars through force main condition assessment

Robert Castillo from Omega Engineers talks about how using condition assessment technologies (SmartBall and PipeDiver) will help the city of Houston extend the capital improvement dollars by identifying and planning repairs of the city’s force main network.

Video

Louisville Water uses condition data from inline inspections to schedule repairs and avoid breaks

Tim Kraus, Vice President and Chief Engineer at Louisville Water talks about being able to make smart decisions using condition assessment data to make targeted repairs for 1/10 the cost of a water main failure.

With advancements in technology and a willingness to develop proactive pipeline integrity programs, utilities can successfully reduce failures, mitigate risk, reduce capital expenditures, and increase confidence in the overall operation of their force mains.

New standards of best practice for force main management involve a variety of methods and technologies to provide data and information with which to make decisions. Utilities can now often perform a detailed condition assessment while the force main remains in service.

There is no “one-size-fits-all” way of assessing force mains. Any approach should be tailored to risk tolerance, material, diameter and past failure history. Savvy utility managers are turning to programs that reduce damage to assets, prioritize investment to minimize community impact of asset failure, and reduce the consequence of failure by enabling system control.

This white paper will highlight:

  • how to develop a risk-based program
  • the most common modes of failure for force mains
  • how to define which of the three approaches to proactively assessing force mains best fits your goals and risk-tolerance
  • how utilities are finding success using these approaches to: prevent failures, reduce capital expenditures, mitigate risk, optimize budget allocation, and increase confidence and level of service.

Case Study

The Champlain Water District utilized a variety of methods, including high-resolution inline leak and air pocket inspection, transient pressure monitoring (TPM), and a structural design check to ensure a critical transmission pipe’s design was sufficient for current operational conditions.

Champlain Water District (CWD) is an award-winning regional municipal organization that supplies drinking water to 12 municipal water systems in Vermont. As the largest water supplier in the state, CWD serves approximately 75,000 residential, commercial and industrial users. CWD draws water from Lake Champlain, and three high-value water transmission mains supply water to the user municipalities. When evidence of corrosion-related breaks was revealed in nearby distribution mains, CWD became concerned that a critical metallic water main in their system could be next.

THE CHALLENGE

After conducting their own risk prioritization plan, Joe Duncan, Chief Engineer for CWD, and his team kept with the proactive mindset and began a transmission main asset management program.

While the transmission system is relatively “young” and had no real break history, visual feedback from crews showed distribution mains in the vicinity of the transmission mains were experiencing corrosion-related breaks and in some instances looking like “Swiss cheese”. Due to the high importance of the transmission pipeline, CWD wanted to understand its condition and forestall potential corrosion issues.

What solutions did Xylem and Champlain Water District come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

VIDEO CASE STUDY

Project Highlights

Design check confirmed that the pipe design was sufficient for current loading

Acoustic monitoring identified no leaks or gas pockets

Transient monitoring revealed no harmful pressure surges

Anticipated repair funding was re-allocated to other capital work projects

Project Details

Solutions
SmartBall acoustic leak detection
Transient pressure monitoring
Strucutral analysis
Pipe Material
Ductile Iron (DIP)
Inspection Length
1.8 miles (2.9 km)
Diameter
24 inches (600mm)
Transmission Type
Water

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Whitepaper:
Metallic Pipeline Condition Assessment

Case Study

The Town of Flower Mound, Texas (Town), worked closely with Pure Technologies to conduct a leak and gas pocket detection survey of approximately 1.91 miles of potable water mains, which included nearly 1.4 miles of metallic pipelines. The Town is home to 70,000 residents and manages both the water and sewer utilities within Flower Mound.

THE CHALLENGE

In 2001 the Town suffered an uncontrolled leak and lost pressure to a third of their system for a two-day period due to a valve that could not be located. This led to an asset management program, and through this program, the 3.5 mile potable water main was identified in 2015 as a main due for inspection.

Inspecting metallic pipelines has been a challenge for utilities because historically there have been few assessment solutions available. Utilities often used indirect methods of assuming the condition of the pipeline or replaced based on age and consequence of failure, not on the actual condition of the infrastructure. The Town enlisted the help of Pure Technologies to provide a comprehensive condition assessment of key sections of their steel, ductile iron and BWP pipes in order to make balanced and accurate decisions and improve the reliability of service within the system.

How was Pure Technologies able to help the town of Flower Mound address this challenge? Find out and explore the results we achieved together by downloading the full case study below.

VIDEO CASE STUDY

Project Highlights

17 sections with defects identified

1 leak found

1 air pocked identified

1 undocumented outlet located

1 defect validated and replaced

Project Details

Services
PipeDiver® electromagnetic inspection

Sahara® acoustic leak and gas pocket detection & visual inspection

Structural design review

Transient pressure monitoring

Timing
September 2015 – December 2015
Pipe Material
Steel, Ductile Iron, Bar Wrapped
Inspection Length
3.5 miles (5.6 kilometers)
Diameter
20-30 inches
Transmission Type
Water

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Whitepaper:
Metallic Pipeline Condition Assessment

Today, new advancements in technologies and data analytics are helping utilities build asset management programs using a risk-based approach to pipeline condition assessment with the lowest financial impact.

There is no one-size-fits-all approach to assessing metallic pipelines. An approach should be tailored within the context of your risk tolerance while taking into consideration the material, diameter, and past failure history. Many different methods and technologies can be combined to provide data and information to make decisions and prioritize pipelines. The approach can range from do-nothing to a full in-line inspection making targeted repairs and be progressive in nature.

This white paper will highlight:

  • how to develop a risk-based program
  • how to define which of the three approaches to assessing metallic pipe best fits your goals and risk-tolerance
  • how other utilities are finding success using these approaches to: extend remaining useful life, optimize capital expenditures, prevent failures, and increase confidence and level of service.

Case Study

To manage remaining useful life of a critical metallic force main, City of Cape Girardeau deploys SmartBall® as screening tool for condition assessment to identify gas pockets and high likelihood areas of internal corrosion.

Desktop studies commonly incorporate data such a pipe material, class, age, and failure history to assist in preliminary condition assessment programs without someone necessarily ever seeing the pipeline. Utilities often use desktop data as an initial step to help shape a management strategy.

For a higher level of condition assessment data, the health of a pipeline can be determined by combining desktop studies with an inline SmartBall leak and gas pocket survey, leading to focused test pits in areas where gas pockets indicate potential internal corrosion, the most common cause of ductile iron force main failure.

As proof of concept, Pure Technologies used the free-flowing SmartBall platform as part of a recent DIP force main condition assessment for City of Cape Girardeau, Missouri.

Project Details

Services
SmartBall leak and gas pocket survey

Condition assessment aided by SmartBall gas pocket location

Field service verification

Ultrasonic Thickness (UT) Testing for structural evaluation

Remaining Useful Life (RUL) analysis

Pipe Material
Ductile Iron Pipe (DIP) HDPE
Inspection Length
3 miles (4.8 km)
Diameter
20-in (500mm) & 24-in (600mm)
Transmission Type
Wastewater

Project Highlights

3 miles total distance inspected

26 gas pockets detected

5 pipes excavated, visually inspected and wall thickness measurements obtained

RUL data determined failures may occur within 2 years where gas pockets detected and 15 to 30 years where gas pockets were not present

THE CHALLENGE

The City of Cape Girardeau (Cape G) proactively manages 550 miles of water and wastewater pipelines for a population of nearly 40,000.

In January 2017, Cape G retained the services of Pure Technologies to field verify and further assess the condition of the Riverfront Force Main, a three-mile pipeline comprised of 20 and 24-inch ductile iron pipe (DIP), with a few replacement sections of HDPE.

Cape G had experienced a failure on Riverfront Force Main on the Memorial Day weekend of 2016. As the force main is relatively new (installed in 2000) and runs along the Mississippi River, the condition assessment of the non-redundant main was critical for the City.

What solutions did Pure Technologies and Cape G come up with to solve this challenge? Find out and explore the results we achieved together by downloading the full case study below.

pipe_diver

On Thursday May 17, thought-leaders, leading utilities, and other industry experts, came together for Xylem’s Modernizing Water Infrastructure Workshop in Laurel, MD. Like Infrastructure Week, the event served as a platform for innovators to connect, discuss, and inspire water industry professionals to solve the problems associated with managing water infrastructure. If you were unable to attend, here are some of the highlights of the day.

From Manure To Modern

The morning session focused on utilities, and began with a keynote presentation from industry visionary, George Hawkins, who provided an energetic analogy on how the manure crisis of the 1800s compares to our current water crisis. While the common person only saw the problem of horse manure, the engineers of the 1800s saw the potential for change and created the car, which eliminated the problem while increasing productivity and reducing costs. That’s what we, as an industry, need to focus on as we modernize water infrastructure — seeing the potential for greatness and improvement through innovation.

Hawkins went on to discuss how we report efficiency. If everything is measured in a productivity approach, seeking additional funding becomes easier. Money has gone farther than ever before in the water infrastructure industry because of the advancements in technology that allow us to work more efficiently and accurately. People are prepared to invest in something that matters to them, especially when they understand that the current monies are going further, and you can prove it. Listen to part of Hawkins’ presentation:

100 Years of Continuous Improvement

Following Hawkins’ passionate keynote address, we heard from Glen Diaz, Division Manager of Water/Wastewater Systems Assessment at WSSC. As WSSC (Washington Suburban Sanitary Commission) celebrates their 100-year anniversary, Diaz reflected on the advancements in technology through the years.

Even in the past 10 years, things have greatly improved in the water industry. Diaz cited the 66” water main break in Bethesda, MD in 2008 and how current technology can aid in preventing future incidents. Diaz went on to discuss how most PCCP failures are due to broken wires and how noisy pipes are typically problem pipes.

However, now, WSSC workers receive mobile alerts, through the implementation of Pure Technologies AFO system, as soon as wire breaks occur so they can address any cause for concern. This system has already helped WSSC avert 20 failure events to date, a $21 million dollar savings on the conservative side! See Diaz’s presentation here:

With Challenge, Comes Major Opportunity

After hearing from WSSC, we heard from Jody Caldwell, Asset Management Director for Great Lakes Water Authority (GLWA), on building an asset management program from the (under) ground up.

Caldwell began with an overview of some of the organizational challenges GLWA is experiencing being a relatively new utility. He talked about the process GLWA went through putting together a 10-year strategic roadmap focused on continuous improvement to overcome the challenges and build a utility for the future. Caldwell went on to discuss GLWA’s pipeline risk management strategy, which uses a quantitative, risk-based analysis to drive decisions. This tiered approach allows them to easily calculate their risk return on investment and ultimately, become a best-in-class pipeline management system. Catch the end of Caldwell’s presentation, as well as the Q&A session.

Extreme Preparation for Extreme Weather

After a brief networking break, there was a roundtable discussion that focused on how leading utilities dealt with the extreme weather conditions this past January. The roundtable featured (from left to right) Joseph Mantua, Deputy General Manager Operations at WSSC; Carlos A. Espinosa, Chief of the Office Of Asset Management at Baltimore City Department of Public Works; and Buddy Morgan, General Manager at Montgomery Water Works (Alabama). Who said the South doesn’t experience cold weather.

The discussion began with the question, “Were there particular pipe materials you found to be problematic during the extreme winter, and if so, what were they?” For the City of Montgomery, AL, cast iron mains had the most problems. Baltimore City was no different, reporting that 98% of the water main breaks were in cast iron pipes, the majority of which were 12” or smaller. WSSC confirmed the cast iron trend, with the majority of breaks occurring in 6 or 8 inch diameter pipes.

In order to prepare for next winter, the utilities agreed for the need to ensure that all their equipment is in working order ahead of time, and have conversations with their crews and contractors to make sure they’re prepared to respond, and recognize the need for additional support services and how to best utilize them. Additionally, the panel agreed that social media played a crucial role in real-time communications with customers, aiding them in being proactive with the media, and helping to communicate status updates. Watch the beginning portion of the roundtable discussion:

The discussion moved on to how to keep employees engaged during extreme weather conditions. Aside from the generous overtime benefits, WSSC brought hot meals to workers, while Alabama Water Works limited hours per week to 65 with 24 hours off before coming back. They also held celebratory cookouts once the weather warmed up.

Be Best-In-Class

After lunch, the afternoon sessions focused on technologies and management best practices. Pure’s very own Mike Higgins, Senior Vice President, Americas, talked about buried infrastructure philosophies utilities can use to manage their most valuable assets. Mike kicked-off his presentation by sharing statistics from the 2017 Infrastructure Report Card from the American Society of Civil Engineers (ASCE).

Following these eye-opening numbers, Higgins shared his insights on success for professionals in the water industry.
Key questions utilities need to answer include:

  • Why do you want to assess your pipeline?
  • What are the goals for your project or program?

 

Typically, the answers should focus on one or more of the following areas:

1) Averting pipeline failure
2) Reducing pipeline risk
3) Extending the life of an asset
4) Increasing sustainability
5) Optimizing CAPEX/TOTEX (capital/total expenditure)

Higgins then shared his secret recipe for the 10 key ingredients to be a best-in-class utility:
1) Focus on operations excellence
2) Coordinate with all key stakeholders
3) Perform necessary Public Relations
4) Create a clearly defined team across departments and disciplines
5) Always aspire towards total pipeline management
6) Prepare for emergencies, they will occur
7) Be opportunistic
8) Continue to innovate
9) Understand limitations of innovative approaches
10) Keep your boots on the ground (maximize the amount of inspected pipe)
 
He concluded his presentation talking about the importance of monitoring key performance indicators (KPIs) and keeping senior leadership engaged. Watch Higgins’ presentation:

The 4th Industrial Revolution

Richard Loeffler IV, Client Solutions Architect at Emnet, then reminded us that the number one criteria for where cities locate is the access to water. Loeffler also stated that we are in the midst of a 4th industrial revolution—IoT (Internet of Things) is changing the way we live, work, and play, and is transforming the fundamental economic cost structure of water and related civic works.

He used the example of South Bend, IN, to illustrate just how effective IoT and RTDSS (real-time decision support systems) can be. Ultimately, it’s all about environmental stewardship — it’s not just about saving money, but about doing the right thing for the world that we live in. View Loeffler’s presentation:

Smart Water

Following Loeffler’s informative presentation, Bridget Berardinelli, VP Product Management And Continuous Improvement for Xylem, stated how smart meters and applying analytics can help utilities generate real results. Berardinelli began by explaining how Sensus develops advanced technology solutions that enable the intelligent use of critical resources.

She covered Advanced Metering Infrastructure (AMI) and explained how to leverage it in order to increase operational efficiencies and improve scalability and flexibility. By delivering machine learning and analytics using a programmatic approach, Sensus is able to inform operational interventions that transform how water utilities operate. View her presentation:

Our Newest Solution

Concluding Berardinelli’s presentation, we heard from Pure Technologies Area Regional Manager, Susan Donnally, on how to manage large diameter water transmission mains. She began her presentation with a discussion on pipeline risk prioritization, stating that using data to drive decisions is a quintessential part of moving towards a proactive asset management approach. She then dove into why pipes fail; noting that age alone is a poor indicator of pipe condition. While there is no singular technology that can identify all of the indicators of pipe deterioration, a holistic, risk-based approach can help.

Donnally then moved on to highlight some of Pure’s latest technology innovations:

  • SmartBall® – in addition to leak and gas pocket detection, the tool now provides mapping, which combines data collected during an inspection with known, aboveground locations and pipeline drawings to create a field-generated GIS map of a pipeline.
  • PipeDiver® – Pure’s free-swimming condition assessment tool is now available with video and can easily correlate the data you’re getting from electromagnetics with actual footage.

 

Additionally, Donnally had a huge reveal! She introduced Pure’s newest PipeDiver solution, the PipeDiver UltraTM (currently in the beta testing phase with a couple of clients), which features high-resolution wall condition information for metallic pipes, such as cast iron, ductile iron, and steel, and is as easy to deploy as the existing PipeDiver. Watch her presentation:

You’re Not Going to Start with Perfection

Vice President of PureAnalytics, Travis Wagner, gave the final presentation of the day on managing distribution systems.

He truly engaged the audience by asking attendees to raise their hands if:

  • They saw a need or value in a pipeline renewal program
  • They agreed that a 10-20% efficiency in renewal programs is OK
  • They thought customer affordability was an issue
  • They had trouble with retirements and recruiting

 
Not surprisingly, most hands were raised! From there, Wagner went on to urge everyone to update their approach.

Utilities need to start asking themselves the following questions:

  • What is the current state of my assets?
  • What is my required level of service?
  • Which assets are critical to sustained performance?
  • What are my best O&M and CIP investment strategies?
  • What is my best long-term funding strategy?

 
Wagner concluded this portion of the presentation with a quote that all utilities should follow: “You’re not going to start with perfection, the goal is to build toward becoming better.”

Next, Wagner moved on to discuss risk management, consequence probability analysis, data collection, and risk mitigation. It was truly an eye-opening presentation:

The day concluded with demonstrations of all the latest technology available to utilities, including a 108” PipeDiver, SoundPrint® AFO system, Sensus meters, Visenti software demos, not to mention some great networking.

Want to learn more about our Modernizing Water Infrastructure Workshop? Check out #H2018Workshop on Facebook, LinkedIn, and Twitter.

 

Airfield location meant inspection scheduling was booked five months in advance.

Water main inspection to manage the critical assets for the Vancouver International Airport takes months of proactive planning, safety and scheduling.

In the management of a major international airport like Vancouver International Airport (YVR), Vancouver Airport Authority (VAA) operation officials inevitably face a number of unique challenges. Compounding the challenges is the fact that the airport runs as a mini-municipality because of its size and island location within the jurisdiction of the City of Richmond.

When carrying out a water main inspection in an airfield location, strict rules apply to how you operate in that area. A well-executed inspection requires a dedication to planning, safety, and scheduling.

Being an airfield location, a lot of detailed planning went into managing this South Runway Watermain Inspection. We stuck to the schedule, met all milestones, and were extremely pleased with the execution of the safety plan, which was critical in this restricted environment.” Stephen Little, Technical Specialist-Mechanical, Vancouver International Airport.

The water line provides an important service to South Terminal and leased buildings.

Project background

Canada’s second busiest airport, YVR, served 24.2 million passengers in 2017. Last year, VAA engaged Pure Technologies to perform a Sahara® leak and air pocket detection inspection on the South Runway Watermain (SRW). Built in 1966, the SRW is a 350mm water main constructed of asbestos cement that runs from the Airport Field Bulk Water Meter to the South Domestic Terminal for approximately 870m (2850 ft.).

The water line provides an important service to both the South Terminal and leased airport buildings, which include a busy McDonald’s, the Floatplane Terminal, Flying Beaver Bar & Grill and multiple aircraft maintenance facilities. The line also runs along the main airfield, and across some taxiing areas, driving home the point that failure is not an option.

The airport receives water from the City of Richmond, which was also keenly interested in the inspection planning, technology and the outcome.

A multi-purpose inspection

The main purpose of the survey was to assess the condition of the main to identify and accurately locate any leaks or air pockets using the acoustic capabilities of the Sahara leak detection tool. VAA wanted a visual take on the inside of the pipe using the video capabilities of the tool’s CCTV camera. In addition, VAA also wanted to map the bends in the line and take GPS coordinates at select points to update alignment plans.

Another important purpose of the inspection was to eliminate water loss at the airport, a goal initiated by management as part of a proactive environmental program to conserve water. Management wanted to locate areas of potential water loss in their system to help achieve their water reduction targets of 30 percent by 2020.

YVR receives water from the City of Richmond via several bulk meter locations. From here, VAA distributes the water throughout Sea Island. The presence of leaks would have an adverse effect on the airport reaching its water reduction targets.

Tethered Sahara tool is propelled by the product flow and features inline video to observe internal pipe conditions.

Sahara leak detection platform selected

Pure recommended the Sahara leak detection platform for its ability to provide same-day results, and to locate small leaks with sub-meter accuracy. The tethered tool is propelled by a small parachute inflated by the product flow.

The Sahara platform also features inline video that allows operators to observe internal pipe conditions, and in many instances, identify the type of leak and other details helpful for planning a repair before excavating.

 Although this first project was limited in scope and budget, because of the criticality of the line, both Pure and VAA put extra care and planning into efforts to ensure a relatively effortless access and retrieval of the condition assessment tool.

The City of Richmond assisted by removing their aging water meter and installing the flange supplied by the Sahara team for the launch of the tool. The City of Richmond then took the inspection opportunity to upgrade the old meter to a newer ultrasonic model.

Airfield location meant maintaining inspection schedule was critical  

As the line was located in the airfield, maintaining the inspection schedule was critical. Security escorts were required at all times for non-YVR employees, which meant scheduling for the project was booked nearly five months in advance.

As well, the inspection was a multi-jurisdictional project, as the pipeline was owned by both the City of Richmond and VAA, requiring close collaboration between all parties. Pure inserted the tool via the City of Richmond’s water meter (in the airfield) and inspected the downstream water main (owned by VAA).

“The South Runway Watermain inspection project was a good opportunity to trial and gain better understanding of the inspection technology. It also allowed us to get a level of comfort in order to identify other areas where we can apply it,” said Little. “Our comfort how well the inspection went is an incentive for us to explore more non-destructive inspection methods.”

The adaptable design of the Sahara tool allowed for a horizontal insertion at the water meter chamber. (Vertical insertion is the more common method for inserting the tool.)

Inspection results

The adaptable design of the Sahara tool allowed for a horizontal insertion (vertical is more common insertion method) at the water meter chamber and the inspection was completed under live conditions without disruption to service, using the water meter bypass and downstream fire hydrants.

In a single day, the Sahara crew inserted the tethered tool through the water meter chamber, inspected approximately 870 meters (2850 feet) and determined the pipeline alignment with all bends and 100-meter intervals marked. In conjunction with the inspection, VAA and the City of Richmond were able to upgrade the old water meter to an ultrasonic unit, a bonus to the inspection goals.

In the end, zero (0) leaks and zero (0) air pockets were identified during the inspection, and CCTV showed some small tuberculation on the metallic bends. Although VAA recognized no immediate concerns, the Airport Authority now knows the correct updated line location and the overall condition of their assets.

Overall, a great success for a pilot project.

 

While metallic rising mains have been historically difficult to manage, a risk-based approach increases confidence in the condition of the pipeline.

Nothing grabs headline news like the failure of a rising main, which can be extremely damaging to the environment and harmful to a utility’s reputation.

Historically, wastewater rising mains have been difficult to manage, especially those made with ferrous materials, where the failure method is slow when compared to concrete pressure pipe. As well, sewer rising mains have special operational challenges that don’t apply to gravity sewer mains as they typically cannot be taken out of service for inspection, and due to the presence of solids in the fluid, rising mains represent a far more abrasive environment than potable systems such that assessment methods for water mains may not be applicable.

The presence of pockets increases the potential of corrosion in metallic pipes.

Gas pockets are of significant concern in rising mains.

The primary failure mechanism of ferrous rising mains is due to internal corrosion. Gas pockets are of significant concern in rising mains, as concentrations of hydrogen sulfide gas within wastewater can be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall. This may cause corrosion and eventual breakdown of the pipe’s wall.

Therefore, a first step in assessing rising main condition should be the identification of gas pocket locations within the pipeline.

Pure Technologies has performed an analysis of rising mains inspected using acoustic based technologies in order to better characterize the frequency and location of gas pockets. Based on the analysis, it was found that 72% of gas pockets were not at known high points or air release valves, therefore, the most precise way to identify gas pockets within a rising main is through the implementation of inline acoustic inspection technologies.

The collection of gas pocket locations alone will not indicate the condition of the pipeline, but instead identifies locations where an increase in corrosion potential is observed. To ascertain the true condition of a pressure pipe, higher resolution electromagnetic technologies are required. These technologies measure pipe wall thickness in ferrous materials and broken wire or bar wraps in concrete pressure pipe.

Once the condition data is collected, advanced analytics can be applied to estimate the pipeline’s remaining useful life.

“Previous analyses involved straight-line assumptions – comparing the pipe wall thickness at installation against what it is today. However this doesn’t give an accurate picture of how pipes degrade…by using statistical modeling we can develop a more predictable degradation rate based off of over 14,000 miles of inspection data Pure has collected over the past 30+ years.”

Jennifer Steffens, Market Sector Leader, Water and Wastewater, Pure Technologies

Jennifer Steffens, Market Sector Leader, Water and Wastewater, Pure Technologies

Desktop studies are not always reliable.

While often the first thought is to replace the aging wastewater assets based on factors such as age and failure history, this option makes neither logical nor financial sense. With so many miles of buried pipelines and such limited capital budgets, utilities don’t have hundreds of millions to spend on replacing pipelines which still have remaining useful life.

At Pure Technologies, we believe there is a better way. A more feasible approach to ensuring the safe operation of rising mains is to undertake a risk-based approach to manage their operation. A risk-based approach will provide decision intelligence on which assets require rehabilitation or replacement to extend their useful life. Or which assets can be left alone.

Our approach is to help utilities evaluate the current state of their buried infrastructure and provide them with high confidence condition and operating data.   We then couple this with our years of extensive experience and project history (more than 12,000 kilometers of pressure pipe assessment) to provide utilities with actionable information, which allows them to make informed decisions as to the management of these critical assets.

Value of a risk-based approach to manage rising mains.

Utilities that embrace a risk-based approach to manage their rising main inventory have found that on average they can safely manage their rising mains for roughly 5 to 15 percent of the replacement cost. This pragmatic approach focuses on providing real condition data through assessment, which can be used to selectively renew isolated areas of damaged pipe in lieu of capital replacement.

Four steps to a risk-based approach.

At Pure, we recommend a risk-based approach to manage wastewater rising mains by focusing on four main areas:

  • Preliminary Risk Analysis
  • Internal Corrosion Potential Surveys using Inline Acoustics
  • Pipe Wall Assessment using Advanced Technologies
  • Condition Data Analysis and Advanced Risk Assessment

Most common reasons for pipeline failure.

Preliminary analysis.

Preliminary analysis includes collecting the right data to develop a prioritized plan for assessment, including the selection of appropriate technologies. To help make preliminary decisions, Pure collects all available information to understand the history of the pipeline and the likely failure modes. The data analysis will provide an understanding of the construction and context of the pipeline. Data of interest typically includes pipe characteristics, installation factors, environmental and performance-related data, operational data, and failure data.

Acoustic-based SmartBall® tool locates leaks and gas pockets

Acoustic-based SmartBall® tool used to locate leaks and gas pockets.

Sahara is an inline tethered tool that can locate leaks and gas pockets.

Internal corrosion potential survey.

An internal corrosion potential survey uses inline tools to locate gas pockets that can increase the potential for corrosion and eventual breakdown of the pipe wall. Pure Technologies typically deploys its acoustic-based SmartBall® leak and gas detection tool, as well as its tethered Sahara® leak and gas pocket detection platform to locate gas pockets in pressurized lines of all materials.

Pipe wall assessment.

While the presence of gas pockets may indicate areas of potential concern, it will not give a quantifiable answer as to the structural life of the pipe.

Pipe wall assessment is completed using a variety of technology solutions to identify defects and deterioration of the pipe wall in a variety of pipe materials. For pipe wall assessment of metallic rising mains, common internal electromagnetic technologies include the PipeWalker® and PureRobotics® platforms, as well as the free-swimming 24-detector PipeDiver® assessment tool, developed to identify electromagnetic anomalies indicating pipe wall loss.

PipeDiver® assessment tool, identifies electromagnetic anomalies indicating pipe wall loss.

Condition assessment analysis.

Condition data analysis and risk assessment evaluates how to safely renew or extend the life of rising mains. The risk evaluation considers not only the probability of failure (condition) of the rising main based on inspection data, but also the consequence of failure in order to make sound engineering decisions.

Understanding the risk of the pipeline is an important step in selecting and justifying the appropriate condition assessment methods. As the risk of the asset increases, the value of using high-resolution comprehensive assessment techniques increases. Higher resolution data results in more confident decision making, and would justify and prioritize the application of assessment techniques.

Diagnostic analytics helps utilities move risk assessment forward.

In the past, inspections were done, the data analysed, and the results passed on to the utility. Pure Technologies now offers a more holistic program of diagnostic analytics. This includes analysis of what caused the corrosion problem within the pipe wall, what the impact the corrosion has on the life of the pipeline, and a prescriptive analysis of how it needs to be repaired or rehabilitated.

The next step gathering momentum? Predictive analysis to elongate service life.

For this Vancouver Island community, tight deadlines, plug valves, and a rising tide were among the challenges faced during this condition assessment project.

Sometimes the catalyst for a pipeline inspection can come from an unexpected source. In this instance, the story began when it was noticed that a sewer pipe was exposed from erosion during low tide along the beach. That observation set the wheels in motion for an eventual inspection of a critical force main that services approximately 41,000 residents in both the Town of Comox and the City of Courtenay on the eastern coast of Vancouver Island.

The pipeline was installed in the early 1980s, and consists of an 8.75 km large-diameter force main that connects the City of Courtenay, Town of Comox and K’ómoks First Nation Community to the Comox Valley Water Pollution Control Centre (CVWPCC). This includes a five-kilometer portion buried in an “intertidal” foreshore section (area between high and low tide).

Over time, a section of beach eroded and exposed the line to coastal wave action (high tide hides the pipe). The Comox Valley Regional District (CVRD) took steps to restore the beach section where pipeline had been exposed, and began developing plans to relocate the exposed force main off the foreshore.

Island community concerned about pipeline risk of failure.

Sensitive location and potential environmental consequences strike nerve with community.

A new concept was developed that would utilize a portion of the existing force main within the foreshore but remove from service the exposed force main. Due to its sensitive location and the environmental consequences of a potential failure, the CVRD elected to complete a highly specialized pipe condition assessment on the entire length of the line to better understand the remaining service life and condition of the force main. As a result, the project timeline was tight, as CVRD needed imminent results to proceed with corrective action immediately should it be required.

The assessment challenges began from the get-go.

The inspected portion of the pipeline was built of two different pipe materials (PCCP and BWP) and three different pipe diameters (450-, 750- and 820-mm). As well, the critical line could not be taken out of service. The CVRD consultant, Associated Engineering, assisted in developing the request for proposal (RFP) process used to select Pure Technologies (Pure) to conduct the condition assessment, which included an electromagnetic inspection, structural curves, leak and gas pocket detection, and transient pressure monitoring.

Pure proposed the acoustic-based SmartBall® tool for the leak and gas pocket detection, and its free-swimming PipeDiver® inspection platform for the electromagnetic inspection of the line.

“This project had a lot of challenges, especially since the asset was so critical to the region. However Pure was able to help us understand the true condition of the line without requiring a shutdown of the critical force main, and has given us defensible information to make informed decisions in the future.”

Kris La Rose, Senior Manager Water/ Wastewater Services, Comox Valley Regional District

Pipeline alignment follows along the Vancouver Island coast.

Transient pressure monitoring used to understand surge pressures within the line.

First, transient pressure monitors were installed at the Courtney Pump Station (CPS). For more than 4 weeks, the recorded pressure data was used to understand the operational and surge pressures within the force main and their impact on the structural integrity of the pipeline.

SmartBall® technology detects and locates acoustic signature related to leaks and gas pockets.

While transient pressure data was collecting, Pure deployed its proprietary SmartBall technology, a multi-sensor tool used to detect and locate the acoustic signature related to leaks and gas pockets in pressurized pipelines.

The tool has the ability to inspect long distances in a single run, and while the SmartBall is deployed, the pipeline remains in service, limiting disruption to customers.

PipeDiver tool collects electromagnetic data regarding the pipe wall.

PipeDiver® electromagnetic technology designed to assess PCCP, BWP and metallic pipes.

In addition to utilizing the SmartBall tool, Pure chose to deploy the PipeDiver platform, a free-swimming condition assessment tool that collects electromagnetic data regarding the pipe wall, and operates while the pipeline remains in service, an important factor for the force main inspection. The tool travels with the product flow and utilizes flexible petals to navigate plug valves, tees and bends in the pipeline.

Crews had to retrieve the PipeDiver tool within a short 20-minute time window.

Tight time-frame for tool insertion and retrieval of sensor data.

Due to the criticality of the line, and a small capacity wet well at the CPS, the inspection teams had a very short time window (20 minutes) to insert the inspection tools. The small capacity wet well also meant that boosting flows was limited – if pumped too hard, the wet well would draw down and empty, and if pumped too slow, the PipeDiver tool could get lodged at the inline plug valves. (Low flow rate is not a significant problem for the SmartBall tool.) The solution was to first use the SmartBall inspection tool to test the flows in order to optimize the inspection approach for the PipeDiver run.

While the low flow rate slowed the SmartBall inspection, a forecast of rain moved up the PipeDiver run a day ahead in order to take advantage of extra flows that could be provided by the wet weather. The tool also had to navigate a series of 90-degree bends and a plug valve with a small port width in the pump station pipe.

Tracking the tools along the beach was fraught with potential for problems. Inspection crews needed to monitor the tidal forecasts in order to access the tracking sensors during the tide ebb, which meant a short window to retrieve the sensor data.

In spite of the challenges and risk, the dynamic four-day inspection proved successful, and went off without a hitch. The Pure Technologies crew and CVRD operators worked very well together, and their collaborative efforts ensured that this important project was successfully completed.

Damp weather didn’t dampen the inspection ingenuity of the team.

Data analysis indicated no electromagnetic distress on inspected pipes.

Based on the inspection data, Pure analysts identified zero (0) leaks, one (1) acoustic anomaly associated with trapped gas, five (5) acoustic anomalies characteristic of transient gas and two (2) acoustic anomalies associated with entrained gas. In particular, gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

The results also showed no indication of electromagnetic distress on the inspected pipes, which was good news, in spite of the corrosive salt water environment.

Overall, the CVRD was pleased with the inspection results, as they were able to understand the condition of the pipeline and make an informed decision for capital improvements. The project demonstrates how the region uses actionable data to effectively manage their finances and risk, while continuing to provide the community with a safe and reliable delivery of wastewater.

 

Pure Technologies completes longest single day pipeline inspection to date using PipeDiver® technology.

From the Colorado town of Buena Vista, the views of the distant Rocky Mountains are deceptively stunning. Up close, the terrain is hilly, inhospitable and extremely remote. With no roads and little access, this is helicopter, snowmobile and 4-wheel-drive country. As might be expected, the logistics of inspecting a water pipeline that runs through this unforgiving territory makes the inspection extremely time consuming and hazardous for everyone.

Until now.

An early start to a long but successful day.

For the Homestake Water Project, the manned electromagnetic (EM) inspection that previously shut down the critical 44-mile (77 km) pipeline for at least one month annually over five years, was now completed in one day, thanks in part to an enhanced PipeDiver® EM tool developed by Pure Technologies.

From 5 months using tradition dewatering and manned entries to a single day. Now that’s progress.

“Amazing,” said Tom Hankins, Supervisor for Homestake Water Project, in describing the Otero pipeline inspection run. “With the PipeDiver tool travelling through the pipeline at three feet per second, we can do what we previously did in five months, [over a five-year period] in just one day…”

Background

Colorado Springs and the City of Aurora are the second and third largest communities in the state of Colorado. The Homestake Water Project (Homestake) is a joint venture between the two cities to collect and transport water from the mountains to the communities that serve almost 1 million people.

The Homestake Water Project includes a collection system, a series of reservoirs, a tunnel that brings water through the continental divide and a pump station that delivers up to 120 million gallons of water per day through the pipe.

The Pure Technologies team mobilizing for the day ahead.

One of the pipelines managed by Homestake includes the 44-mile Otero Discharge Pipeline, a large diameter (66-inch) non-cylinder prestressed concrete pipeline (PCP) built in the early 60s by the Cities of Aurora and Colorado Springs. In the past several years, the pipeline has suffered a few major breaks and non-surfacing leaks. The critical pipeline, which provides 60 to 70 percent of Colorado Springs’ and Aurora’s water, is in a high-risk location, with few roads and steep inclines, and recently the pipeline has suffered catastrophic failures.

Variety of methods used to inspect the pipeline

Over the past ten years, Homestake has deployed a variety of methods to inspect the pipeline. This includes visual, above ground, manned electromagnetic cart, and inline leak detection using the SmartBall® platform, of which Homestake has been a licensee for more than six years. Homestake conducts their own SmartBall inspections, analysis and leak verification of the pipelines they manage.

Beginning ten years ago, over a five-year period, Homestake shut down the Otero Discharge Pipeline each September to perform a condition assessment on certain sections of the pipeline. The shutdown included two weeks just to drain the pipeline to prepare it for a manned electromagnetic (EM) inspection tool, and another two weeks to perform the inspection.

“This task is hazardous,” says Tom Hankins, “not just to the mobilization crews, but also to the inspection teams inside the pipe who required rope support on the steep slopes.”

Because Homestake enjoyed a good relationship with Pure Technologies and knew of its innovative inspection technologies, when Pure broached the subject of using an enhanced PipeDiver electromagnetic tool on the remote 44-mile Otero District pipeline, without the need for dewatering, Homestake became keenly interested. Especially as Pure Technologies was able to develop a new exciter for the PipeDiver tool, which could be used on non-cylinder PCP and deliver higher resolution data than in the past.

Getting the star of the show (aka. PipeDiver) ready.

PipeDiver platform collects EM data and operates while pipeline remains in service

The PipeDiver platform is a versatile, free-swimming condition assessment tool that collects electromagnetic data on the prestressing wires, and operates while the pipeline remains in service. The tool has specialized electromagnetic sensors to identify and locate prestressing wire wraps, which are the main structural components of PCP and PCCP, and the primary indicators that the pipe will fail.

And so the planning began. The purpose of Homestake long distance PipeDiver inspection was to locate and quantify the amount of the prestressing wire wraps on all 44 miles in one run, identify the individual pipe sections with distress growth, and drive repair/replacement decisions. A long, tall order, indeed.

Final deliberations before the big event.

High-risk inspection not without its challenges

The proposed inspection was a technically challenging, high-risk project. The teams put more than six months of planning into the inspection logistics, and Pure Technologies worked closely with Homestake to ensure existing facilities could be used for the tool’s insertion and extraction. Homestake also facilitated a calibration with the new tool prior to inspection, which would help with wire break identification and quantification.

Safety a major issue propelling the inspection

In order to inspect the largest portion of the Otero Discharge Pipeline, the PipeDiver was inserted into a surge tower located 600 feet above the pipeline. This also required a rope crew and a fully-suited diver with an umbilical line to rappel via a sled 600 feet down the 66-inch pipe in order to align the PipeDiver in the proper direction. Once the tool was set in the right direction, the rope team safely hauled up the diver and cart.

The pumps were turned on, and the PipeDiver sailed off without a hitch.

“Safety is a major issue because of the rough terrain as the pipeline slices through the Rocky Mountains with lots of hills, highs and lows, which required lots of ropes to get in and out, with the crews experiencing slips and falls…this way the inspection is conducted inside pipe, which is much safer…it does a better job.”
Tom Vidmar, Superintendent of the Homestake Water Project

In addition, the mobilization team installed 55 tracking sensors along the 44-mile pipeline route to monitor the PipeDiver tool as it traversed the inhospitable and extremely remote pipeline alignment.

No drama, no fuss… just a job done well.

Recognized as longest single day PipeDiver tool run in the history of Pure Technologies

Contingency plans were developed in case the PipeDiver tool got hung up along the 44-mile route, but in the end, less than 24 hours later, the tool successfully sailed into the surge pond, to the applause of the Homestake and Pure crews. The PipeDiver tool was removed from the surge pond and the pipeline data retrieved.

In the end, the PipeDiver electromagnetic inspection, at 44 miles long, was recognized as longest single day run for the tool in the history of Pure Technologies. With Pure Technologies now analyzing the electromagnetic data, Homestake will soon have information on the location and amount of broken prestressing wires on all 44 miles of the pipeline, which in turn, will drive repair/replacement decisions for the proactive water authority.

All in all, not bad for a day’s work.

Technology-based, people-driven.

Case Study

The Washington Suburban Sanitary Commission (WSSC) is the 8th largest water and wastewater utility in the United States, serving over 460,000 customer accounts and 1.8 million residents in Montgomery and Prince George’s County, Maryland (suburban Washington D.C.).

WSSC operates nearly 5,500 miles of water mains, with approximately 145 miles comprised of large-diameter Prestressed Concrete Cylinder Pipe (PCCP) equal to or greater than 36-inches in diameter.

Project Details

Services
SmartBall®
Acoustic Leak Detection
PipeDiver® – Condition Assessment
PureRobotics® – Pipeline Inspection
SoundPrint® AFO – Acoustic Fiber Optic (AFO) monitor­ing
Timing
2014
Pipe Material
PCCP
Inspection Length
145 miles
Diameter
36-inches

Project Highlights

The Assess & Address cost was roughly 6% of the capital replacement estimate of $2 billion

95% of the pipes inspected by Pure Technologies have no deterioration at all

Pure has identified less than 2% of pipes in need of immediate repair

A capital replacement program would have replaced a large amount of pipe in good condition

Challenge

After WSSC began experiencing major PCCP failures in the 1970s, it developed a strong commitment to infrastructure management technology in favor of large capital replacements. Beginning in 2007, WSSC and Pure Technologies began a partnership to create a comprehensive PCCP management program.

Pure Technologies Assess & Address approach to pipeline management is built on extensive research and data from over 8,000 miles of pressure pipe inspection which has found that less than 1 percent of pipelines need immediate repair. Assess & Address programs focus on identifying vulnerable areas of a pipeline and completing selective rehabilitation and replacement in favor of full-scale capital replacement, often saving the utility millions of dollars.

Solution

Pure Technologies uses several solutions for WSSC’s PCCP management program that effectively inspect the pipeline for leaks, gas pockets, and structural deterioration. Pure also provides real-time monitor­ing of the pipelines to alert the WSSC when indi­vidual pipe segments experience prestressed wire breaks and are approaching a high risk of failure.

Pure’s SmartBall® Acoustic Leak Detection Technol­ogy is used to identify leaks and pockets of trapped gas, allowing for proactive repair. The SmartBall inspection tool is a non-destructive, free-swimming technology that measures the acoustic activity associated with leaks and gas pockets in pressurized pipelines. Early identification and repair of leaks and gas pockets reduces water loss and structural deteri­oration and is crucial in understanding the baseline condition of a pipeline. Pure Technologies regularly deploys SmartBall leak detetction as part of the pro­gram having identified several major transmission mains leaks within WSSC’s system to date.

WSSC Pipelines are also inspected for structur­al deterioration using several of Pure’s platforms. Manned visual and sounding inspections of dewa­tered pipes help identify visible structural damage like corrosion, delamination, and cracking. Pure also uses PipeDiver® and PureRobotics® Electromagnet­ic (EM)Technology Platforms to locate and quantify broken prestressing wires in each pipe section.

Information from these inspection techniques are combined to provide actionable information (including structural modeling and analysis), which allows WSSC to safely manage their PCCP inventory while minimizing renewal projects.

In addition to regular condition assessment, WSSC began using Acoustic Fiber Optic (AFO) monitoring in 2007. Ultimately, the program will monitor up to 145 miles of 36-inch and larger PCCP within WSSC’s system.

AFO technology monitors the condition of PCCP by tracking the amount of wire breaks in each pipe section. The system allows WSSC to monitor pipe­line deterioration and see at-risk pipes before they fail. As wire breaks occur, the data is analyzed and reported to WSSC by e-mail and advanced GIS and web-based reporting systems, allowing for real-time management of WSSC’s system.

Results

While WSSC’s PCCP program is one of the largest and most advanced infrastructure management programs in the industry, the cost of Pure Technologies Assess & Address model is roughly 6 percent of the $2-billion capital replacement estimates.

To date, Pure Technologies inspections have shown that about 95 percent of WSSC’s pipes are in “like new” condition and less than 2 percent require any immediate rehabilitation or replacement. By identifying select distressed areas, WSSC was able to avoid a full replacement program and avoided massive capital replacement costs by rehabilitating the identified sections.

Since the program’s inception, no PCCP failures have occurred for any transmission main managed under the program.

Case Study

The Trinity River Authority of Texas (TRA) owns and operates 8.5 miles of 30-inch BWP and PCCP that supplies raw water from Lake Arlington to the Tarrant County Water Supply Project Water Treatment Plant in Euless, Texas.

The 30-inch pipeline, in conjunction with a parallel 54-inch pipeline, conveys raw water to the Authority’s 87 mgd WTP. Treated water produced at the WTP is supplied to five cities in the mid-cities region between Dallas and Fort Worth including Bedford, Colleyville, Euless, Grapevine and North Richland Hills.

Project Details

Services
SmartBall® Leak Detection
PipeDiver® Condition Assessment
Transient Pressure Monitoring
C303 Bar-Wrapped Pipe structural performance curves
Timing
November 2012 – July 2013
Pipe Material
Bar-Wrapped Pipe and PCCP
Inspection Length
8.5 miles (14 km)
Diameter
30-inch (750mm)
Transmission Type
Raw Water

Project Highlights

SmartBall survey identified 4 leaks and 3 air pockets

Only 1% of BWP sections identified as distressed

TRA verified and repaired 3 high-risk BWP sections

Cost was roughly 4% of the replacement estimate of $25 million

Challenge

TRA had originally planned to replace this pipe­line, but chose to assess and selectively rehabili­tate the pipeline by finding solutions that could identify the most distressed areas. The pipeline spans about 8.5 miles and is made up primari­ly of BWP, although there are some sections of PCCP. It was constructed in 1973.

Solution

In November 2012, TRA began a condition assessment program that included transient pressure monitoring, acoustic leak and gas pocket detection, internal electromagnetic inspection, and structural condition assessment including finite element analysis.

For the leak and air pocket assessment, TRA used SmartBall® technology. The SmartBall inspection tool is a non-destructive, free-swim­ming technology that measures the acoustic activity associated with leaks and gas pockets in pressurized pipelines. When acoustic anomalies are present, the data is analyzed to determine if it is a leak, gas pocket, or just an external sound.

Regular leak detection inspections can help util­ities identify leaks that may not be visible at the surface. By repairing leaks, utilities can reduce their non-revenue water and prevent pipeline failures, as leaks are often a preliminary indi­cation of pipeline deterioration. Location and elimination of air pockets is also beneficial as it reduces pressure on pumps that are attempting to pump water past a gas pocket.

For the structural inspection, TRA used PipeDiver®, a free swimming electromagnetic tool that identifies wire breaks in PCCP and bar breaks and broad areas of cylinder corrosion in BWP using electromagnetic technology. The tool oper­ates while the pipeline remains in service.

Although BWP looks similar to Prestressed Con­crete Cylinder Pipe (PCCP) in cross section, their design and materials are significantly different. PCCP is a concrete pipe that remains under compression because of the prestressing wires, with the thin-gauge steel cylinder acting as a water membrane. With BWP, the cylinder plays a much larger role in the structural integrity of the pipe. BWP is essentially designed as a steel pipe with mild steel used to manufacture the steel cylinder and steel bars.

As a result, the bar in BWP and wire in PCCP respond differently to environmental conditions that facilitate corrosion. The high strength steel wire in PCCP is smaller in diameter and wrapped under higher tension, therefore corrosion makes it quite vulnerable to breakage. The mild steel bars in BWP are thicker in diameter and wrapped under less tension, therefore corrosion takes sig­nificantly longer to lead to breakage.

The engineering services portion of the project was completed to identify optimal operating conditions for the pipeline and determine the structural performance of the pipe materials. This included creating performance curves for TRA’s BWP, as well transient pressure monitor­ing.

The BWP structural performance curves allowed TRA to determine which pipe sections to exca­vate and verify. By determining the bar break yield limit for the specific pipe material, TRA was able to identify which pipe sections should be immediately addressed and which could remain in safe operation.

Results

The SmartBall® survey identified four leaks and three gas pockets. Although the four identified leaks were small (less than 2 gallons per minute), one was located in the front yard of a brand new church building and could have caused signif­icant water damage had it not been repaired immediately by TRA. Water from this leak was visible at the surface 325 feet away from the actual leak location.

The structural inspection using PipeDiver® iden­tified four PCCP pipes with electromagnetic anomalies resembling wire breaks. The inspec­tion of the BWP identified 14 pipes with bar break damage and 72 pipes with electromagnet­ic anomalies resembling cylinder defects out of 1,284 inspected pipes.

TRA has verified and repaired three sections of BWP that were beyond the yield limit deter­mined by the structural performance curves. Upon verification, TRA and Pure determined that distress areas identified in the inspection were accurate and the excavated pipe sections had bar breaks and corrosion.

By repairing specific pipe sections with dete­rioration, TRA was able to avoid replacing the entire 8.5 mile pipeline at a high capital cost. Completing condition assessment has also allowed TRA renew its pipeline infrastructure and continue providing reliable service to cus­tomers in the region.

Case Study

Intermunicipal Service Oeiras and Amadora is a water management company responsible for the distribution of drinking water for the municipalities of Amadora and Oeiras in the Lisbon region of Portugal. SIMAS Oeiras e Amadora distributes water to more than 350,000 customers who have come to rely on the public company for their water services.

Project Details

Services
SmartBall leak detection inspection
Pipe Material
Ductile iron
Inspection Length
2781 meters (2.6 miles)
Diameter
600mm (24-inch)
Transmission Type
Water

Project Highlights

Total of 1.7 miles (2.78kms) of 5-year-old pipeline inspected

Inspection located one (1) leak 863 meters from insertion

Leak repaired and allowed SIMAS Oeiras e Amadora to recover costs associated with the loss of non-revenue water

Challenge

The F. Passarinhos-Atalaia duct is a pressurized pipeline that supplies water to one of eight reservoirs operated by SIMAS Oeiras e Amadora in the municipality of Amadora. Installed in 2007, the large 600 mm (24-inch) transmission main, made from ductile iron material, delivers drinking water to approximately 31 percent of Amadora’s residents, making it a critical part of the municipality’s buried infrastructure.

In 2012, SIMAS Oeiras e Amadora detected a noticeable pressure drop in the system, indicating the possibility of a critical leak, the predecessor of a potential rupture that could negatively impact the environment and significantly disrupt day-to-day life in the community.

In addition to physical losses of water caused by a small leaks, the escaping non-revenue water can eventually erode the surrounding soil making the area more prone to washouts or sinkholes, a major headache especially in densely populated areas. Unplanned excavations to repair unforeseen leaks can also erode consumer confidence in a public utility.

Solution

When traditional leak detection methods—geophones and acoustic correlators­ were unable to detect the location and size of the leak, SIMAS Oeiras e Amadora called on its contractor to perform a leak detection survey using the innovative SmartBall tool from Pure Technologies (Pure).  Because of the criticality of the line, the survey was conducted while the pipeline remained in operation.

Pure’s patented SmartBall tool is an aluminum-core, foam-shell ball packed with several different sensors that can be launched into a water main without any disruption to client service.

Unlike traditional external listening tools that have limited success on large diameter pipes, SmartBall is the industry’s only free-flowing multi-sensor technology that provides the highest degree of accuracy, since as the ball rolls, it can inspect every inch of a water main to detect potential problems such as leaks and gas pockets. Its highly sensitive acoustic sensors can locate ‘pinhole’ leaks and gas pockets within a location accuracy of 1.8 meters.

Results

The SmartBall was inserted into the pipeline through a 6” gate valve and the journey took two hours and 49 minutes. One small leak was detected, 863 meters from the insertion site. This leak was repaired and allowed SIMAS Oeiras e Amadora to recover costs associated the loss of non-revenue water, had it remained undetected.

Although the SmartBall tool detected just one leak, the inspection gave SIMAS Oeiras e Amadora the capacity to assess assets from inside the pipe rather than drawing conclusions from indirect, external clues. If leaks are discovered early, operators can take necessary action to makes repairs before they become a major problem.

This process allows progressive operators like SIMAS Oeiras e Amadora to develop a sustainable long-term strategy for managing their critical buried assets.

Case Study

In March 2014, Pure Technologies completed a successful leak detection survey on behalf of Mancomunidad Comarca de Pamplona (MCP). The inspected pipeline is part of the MCP’s water supply network, was constructed 20 years ago, and traverses from Olaz – El Cano Pump Station to the Gorraiz Reservoir for 2.4 kilometers.

The main’s purpose is to keep water supply to the town of Egües, which features a hotel and golf course. The pipeline has an operating pressure of 12 bar and is pump operated with 50 litres per second during winter months and 100 litres per second during summer season because of increased demand. The inspection was performed in two runs to proactively address water loss on the transmission main.

Project Details

Services
SmartBall® Leak and Gas Pocket Detection
Timing
March 2014
Pipe Material
Ductile Iron
Inspection Length
2.4 km (1.5 miles)
Diameter
400mm (16-inch)
Transmission Type
Water

Project Highlights

SmartBall® leak detection located 4 leaks in 1.49 miles (2.4 kms) of inspection

3 of 4 leaks have been verified and repaired by MCP

Leaks as small as 1 litre per minute identified by SmartBall technology

Challenge
MCP is very dedicated to controlling water loss and completing regular leak detection; they have a permanent internal group with the unique mandate of finding leaks. Typically, they use an advanced SCADA system to identify an area with a leak and then experienced technicians use geophones to establish the exact location of the leak. Using this procedure, MCP has reached a Non-Revenue Water (NRW) level of roughly 10 percent of in their entire network. However, the Impulsión de Gorraiz had a known leak that could not be pinpointed precisely. MCP knew its elevation coordinates but couldn’t identify its exact location using traditional methods.

Solution
With a philosophy of continuous improvement, MCP used Pure’s services to perform a leak detection survey with SmartBall. To supplement its internal leak detection team and SCADA system, MCP wanted to test the validity of an inline leak detection tool and locate the known leak on this pipeline. MCP places equal importance on identifying large leaks and small leaks.

While large leaks leak at a much higher rate, identifying them only eliminates a leak at the tail end of its life. In terms of reducing NRW, locating small leaks may actually represent the best opportunity for long-term water loss reduction. Catching a leak while it is very small prevents the decades of sustained water loss that would occur as it grows into a large leak. While large leaks are important to locate, using technology that can find small leaks on large-diameter pipelines can prevent the development of large leaks and play a vital role in the safe management of a pipeline network.

MCP used SmartBall® leak detection for the inspections. The tool is a free-swimming leak detection platform that operates while the pipeline remains in service. It is capable of completing long inspections in a single deployment and is equipped with an acoustic sensor that identifies acoustic anomalies associated with leaks; the acoustic signature is then analyzed to determine if it is a leak, air pocket, or an external noise.

To track the tool as it traverses the pipeline, SmartBall receivers (SBR) are placed strategically throughout the planned inspection route. As the tool traverses, it makes a sound that is recorded by the receivers to determine its position on the pipeline; this system allows leak locations to be estimated typically within 1.5- meters (6-feet) of the actual leak location.

Due to a 12 bar pressure at the pump station, a new high pressure insertion cap was designed and fabricated to assist with insertion procedure together with a pulley system that allowed the SmartBall insertion claw to be pushed into the pipeline. In order to ensure the highest level of accuracy, additional SBR points were mounted to track the tool closely and a mobile SBR unit was also used. At the reservoir, a small-diameter net was used to retrieve the tool after the inspection was completed.

Results
Upon completion of the inspection, data analysis revealed four acoustic anomalies resembling leaks despite MCP expecting only one leak along the main. Using updated client estimates and the SmartBall tool’s joint detection feature, Pure identified the exact location of three of the four leaks with an accuracy of less than 0.5 meters, including the known leak. The fourth leak verification has been deferred by MCP until a later date. The close location accuracy was confirmed after MCP excavated the leak locations for repair. In addition to the accuracy, the inspection was also successful in identifying small leaks. The leaks confirmed through excavation were as small as ~0.1 liters per minute.

Based on the inspection, MCP was very satisfied with the technology and information that will be used for future management of their network.

SmartBall®

Free-swimming solution for water, wastewater, and oil and gas pipelines that can complete long inspections in a single deployment.

Accurate leak and gas pocket detection without service interruption.

Make short-term repair and long term asset management decisions with Pure’s SmartBall free-swimming inspection platform.

Leaks on any type of pressure pipe can be a precursor to larger failures, failures that will cost utilities money, and reduce public confidence in service levels. By using Pure’s SmartBall platform leaks can be addressed before larger, more severe failures occur. Finding leaks is an important aspect of managing pipelines and understanding their condition. Inline leak detection, when combined with other Pure Engineering Services, can be used as a screening solution as part of a comprehensive condition assessment inspection or program.

SmartBall based mapping utilizes the latest accelerometer and gyroscope technology to create a field generated X and Y map of a pipeline, which can be used by pipeline mangers to better understand the alignment of their pipes relative to other critical assets, plan maintenance work more efficiently, reduce the likelihood of third party damage and conduct more accurate hydraulic modelling.

SmartBall can also be a key solution in reducing water loss in previously neglected assets by detecting leaks on large diameter mains, helping utilities locate and repair leaks before they surface. These large, long run-time leaks have a significant impact on Non-Revenue Water as the volume of water lost with these leaks is often more than those of small diameter mains.

Benefits

  • Easy to deploy through existing pipeline features
  • No disruption to regular pipeline service
  • Ability to live track up to 3,000ft (1,000m) before and after each tracking point
  • Can complete long inspections in a single deployment
  • Preliminary leak locations provided 48 hours after the inspection
  • Mapping to confirm pipeline alignment
  • Measures pressure profile

Related Article

In June of 2016, Suez retained the services of Pure Technologies to perform a SmartBall® inspection of two critical water mains, the Grigny Water Main and Les Halles Water Main, both located near Lyon.

Learn more

Featured Case Study

Waternet

The Netherlands faces unique challenges with their underground pipe networks due to their proximity to numerous dykes that regulate water levels.

Because pipe failures can lead to drastic consequences for Dutch infrastructure, Waternet undertook a leak detection program for three major pipelines that pass various critical infrastructure including dykes, motorways and airport runways.

PureRobotics®

PureRobotics is a powerful robotic pipeline inspection system that can be configured to inspect virtually any pipe application.

Identify problem pipeline areas more easily using a robotic crawler

PureRobotics is a modular, powerful robotic inspection system that helps utilities screen their network for problem areas and gain a better understanding of the condition of their assets.

The robotic crawler is designed to easily transport sensors and tools through water pipelines that are either dewatered or depressurized.

The robot is a multi-sensor platform that carries a variety of condition assessment tools inside the pipeline in a single deployment. The platform also provides live video that can aid in detecting anomalies within the pipe. In addition, the tethered tool is an unmanned solution, which makes inspections significantly safer.

Combined with Pure Technologies’ advanced engineering solution, the PureRobotics platform delivers comprehensive and actionable condition assessment data in a flexible manner giving utilities reliable information to act on with confidence as part of an asset management program.

Benefits

  • Quick and easy to deploy
  • Modular to adapt to many pipe conditions
  • Dewatering not required
  • Live video stream
  • Safer than manned entry

Related Article

A growing number of proactive municipal utilities and power generating operators across North America are reaping the benefits of deploying the latest robotics crawler from Pure Technologies to assess the condition of their pipeline networks and save millions of dollars in water loss and prevented breaks.

Learn more

Featured Case Study

City of Saint John, New Brunswick, Canada

The City of Saint John provides raw water for industrial customers via the Industrial Water Transmission Main, a 1500 mm and 1350 mm (60-inch and 54-inch) pipeline constructed in the early 1970s. Managing the integrity of this critical main is key to maintaining continued operation and production for major industrial plants in the region. During a shutdown in 2017, the tethered PureRobotics® platform was deployed to gather information on the current condition of the Industrial Water Transmission Main.

In North America, the material and size of pipes that make up water and sewer networks range widely. Because these pipeline systems are so complex, it requires a strategic approach based on risk and real data for effective long-term management.

Worker inspecting pipe

Historically, however, it has been challenging to gather real data that can shape defensive capital decisions for an entire system. The assessment of metallic pipelines — which make up most water and pressurized sewer networks — differs from prestressed concrete cylinder pipes (PCCP), both in terms of failure modes and in the fact that metallic pipe materials are featured in both transmission and distribution networks.

While PCCP assessment and management have been successfully used by utilities for years, effective assessment solutions for ferrous pipe have only recently been commercialized.

In 2011, Pure Technologies began an initiative to help close the gap in metallic pipe assessment technologies, and focus attention on gathering honest feedback from proactive utilities on what solutions are needed to effectively manage metallic pipe.

Seven years later, Pure Technologies reports that notable progress has been made with the development and advancement of assessment technologies for metallic pipeline networks.

Team of workers with a metallic pipe

Many proactive utilities involved in guiding Pure’s research efforts

Proactive utilities have been involved in the metallic pipe initiative, and instrumental in the development of new inspection tools for metallic pipe, both by providing feedback that helps guide research and development, and by providing opportunities that allow solution testing in live operating conditions. As a result of these efforts, there has been significant improvements to the technologies available to utilities for assessing the condition of metallic pipelines in both transmission and distribution networks.

For large-diameter transmission mains, there is a well-developed business case for assessing these mains as they approach the end of their useful life. These pipelines typically carry a high replacement cost and are higher risk — due primarily to their size and criticality — making it important for utilities to fully understand the condition of the asset.

Armed with real condition data, utilities can make a defensible renewal or replacement decision about the pipeline. Based on well over 14,000 miles of data, Pure Technologies has found that only a small percentage of pipes are in need of immediate renewal.

Small diameter metallic pipe leak

Case for using inline tools for small diameter pipelines

In distribution networks, however, the case for condition assessment is more challenging as smaller pipelines can sometimes be replaced cost-effectively. Despite this, the process for making a replacement decision should be based, whenever possible, on risk and real data.

With the EPA suggesting that between 70 and 90 percent of pipes being replaced have remaining useful life, the case is even stronger for collecting condition data to drive the decision making to help utilities spend their replacement dollars more efficiently and avoid replacing pipe with remaining useful life.

In some instances with smaller diameter pipes, it is often cost-efficient to use inline tools to gather detailed screening data on a pipe-by-pipe basis to determine if replacement is necessary.

A new approach to metallic pipeline management

While there is no silver bullet technology for assessing metallic pipelines, Pure has developed a flexible, risk-based approach to help utilities better understand their infrastructure, gather actionable data and prioritize both short and long-term management efforts.

Over the past few years, Pure has worked along proactive utilities to develop its data-driven Assess and Address® approach, which focuses on four main areas:

  • Understand
  • Assess
  • Address
  • Manage

Through the implementation of programs across North America, Pure has found that the majority of pipelines 16 inches and above can be cost-effectively managed for between 5 and 15 percent of the replacement cost.

Starting an effective pipeline management program

The first step of any pipeline management program is understanding the system-wide risk along with the benefits and limitations of assessment solutions. This allows for the development of a defensible management strategy that can be implemented to maintain and extend the life of the assets.

Many technologies now exist to provide a snapshot of a pipeline condition at various levels of confidence. It is therefore prudent for utilities to approach technology selection and subsequent analysis based on the risk of each pipeline.

A more thorough risk assessment involves estimating the Consequence of Failure (CoF) and the Likelihood of Failure (Lof) of each pipeline based on internal knowledge, operational history and pipeline characteristics. This initial risk assessment determines which areas of the system require further assessment to acquire real condition data and provides the utility with the necessary information to make an informed technology selection.

By using risk to guide management strategies, owners can ensure they are implementing the right approach, at the right time, with the lowest financial impact. The goal of a management program should always be o focus resources on managing the asset while safely getting the most service life out of the pipeline.

Sinkhole in a street

Reducing the Consequence of Failure

Reducing CoF comes down to improving emergency events through field operations efficiency. Studies have shown that the time to shut down a pipeline had more impact on the consequence of failure than the diameter of the pipeline.

Utilities can reduce CoF — and in turn risk — by gaining a better control on their system, which can be achieved two ways:

  • 1. Adding valves and redundancy in the system
  • 2. Knowing the location, condition and operability of control points

For example, if a pipe fails and utility operations staff are unable to locate valves — or the valves are inoperable when they are located — it will take longer to isolate a pipe failure. This will result in greater damage, more water loss and longer outages and repair times as a result of the failure. Implementing a proactive program for control assets that focus on providing better data for field staff reduces CoF by decreasing emergency response time.

Reducing the Likelihood of Failure through condition assessment

Many factors influence the likelihood that a pipeline will fail. Metallic pipelines, specifically, have a variety of failure modes and require a wide array of technologies to accurately assess their condition. Until recently, technologies for metallic pipe assessment have been unavailable or limited in their viability.

As a result, lower risk metallic mains have historically been prioritized for replacement using age, material and break history, while higher risk mains have sometimes been assessed with test pits along the length of the pipeline. After test pitting, statistical methods are used to extrapolate the condition of the test pit locations along the entire pipe length.

Through the development of metallic assessment solutions, condition data shows that pipe distress is often random and localized, meaning that an area of distress identified during the test pit method may inaccurately identify the entire pipeline as distressed, conversely, identify the entire length of pipeline as in good condition.

The development of reliable inline condition assessment tools provides owners with pipe-by-pipe data that gives a more complete picture of the actual condition of the pipeline. This allows for a more targeted management of small sections of pipe instead of generalizing the condition of an entire pipe length. It also allows for the collection of real data to drive pipeline renewal, which allows for more defensible capital decision making.

Case Study

The Netherlands faces unique challenges with their underground pipe networks due to their proximity to numerous dykes that regulate water levels.

Because pipe failures can lead to drastic consequences for Dutch infrastructure, Waternet undertook a leak detection program for three major pipelines that pass various critical infrastructure including dykes, motorways and airport runways.

Extensive testing was done by officials and Pure Technologies prior to the inspection to ensure the technology could offer a comprehensive leak assessment of the pipeline’s condition.

Project Details

Services
SmartBall® leak and gas pocket inspection
Timing
2013-2014
Pipe Material
PCCP
Inspection Length
195 km (121 miles)
Diameter
1200mm-1500mm (48-60 inch)
Transmission Type
Water

Project Highlights

195kms

of pipelines inspected

3

leaks located

3

leaks verified

Risk mitigated on critical pipeline
Challenge
Most of the Netherlands is situated under sea level, and a large system of dykes protects the land from rising water, while also connecting villages and cities. Water pipelines are often laid in close proximity to the dykes, meaning burst pipes would have devastating e­ffects on the road infrastructure and the surrounding communities.

Today, the aging dyke system is eroding the pipelines foundation causing stress and increasing the likelihood of failures. As a result of several incidents with failing or leaking pipelines in the vicinity of dykes, their owners issued a decree that required water utilities to prove the integrity of its buried assets. Waternet, the regional public water authority for Amsterdam, identified several pipelines of particular concern where a small leak from a pipeline could impact dyke integrity and a risk analysis discovered areas of pipe weakness. Based on these results, authorities determined that further testing in the form of inline leak detection should be performed.

Before embarking on inline leak detection, local officials required several rounds of extensive testing of the proposed technology to demonstrate e­ffectiveness in detecting and locating small leaks in the pipeline. In addition, since the scope of inspection included approximately 180 km of concrete pipelines, the leak detection technology had to demonstrate the ability to inspect long sections of pipe for the project to be most e­ffective.

Solution
Waternet partnered with Pure Technologies to perform inline inspections on three separate pipelines.

The SmartBall® leak detection tool was chosen to assess the integrity of the pipelines and to find leaks along the length of the pipe. The SmartBall tool is a free-flowing leak detection platform that operates while the pipeline remains in service. It is capable of completing long inspections in a single deployment and is equipped with an acoustic sensor that identifies acoustic anomalies associated with leaks and air pockets.

Typically inserted through an existing valve, it travels with the water flow recording the acoustic environment within the line. The SmartBall tool is then removed by either deploying a net at a predetermined extraction point or at another discharge point of the pipeline. The data is stored on the device and analyzed upon completion of the inspection. It is able to travel through long sections of pipe gathering approximately 18 hours of data, making it the ideal solution for the long pipelines of the Waternet leak detection program.

Calibration tests were done to conform to the strict requirements implemented by the dyke owners who wanted clear indications on the lower leak detection limit specific to the composition of the pipe. A calibration stack was developed and extensive tests were performed, simulating leaks to create a calibration curve for various leak sizes. The tests proved SmartBall could detect the leaks smaller than the threshold set by the dyke owners.

Results
Pure Technologies performed SmartBall inspections for Waternet along the WRK pipelines. These pipelines run mainly through rural farmland but also cross through critical dyke systems.

The first portion of the inspection began in 2013 when 146 kilometres of pipeline was broken into eight lengthy inspections. In 2014 the remaining 49 kilometres were inspected. Three leaks were found and verified during the inspection of the entire 195 kilometres of pipeline.

Pure Technologies worked closely with Waternet to fulfill the comprehensive requirements of the leak detection program required by the utility. The importance the dyke system to the protection of the country’s infrastructure and communities mean the integrity of the pipelines must be maintained. The inline leak detection program gave Waternet the necessary information to fulfill their commitment to the dyke owners, and help extend the life of these critical pipelines.

Case Study

This preeminent steel producer is a North American leader in advanced steel manufacturing technology. Typical to most steel processing plants, this mill uses recirculated water for a broad variety of purposes, including cooling the blast furnaces, quenching slag, and drawing heat from the overall hot plant environment.

Project Details

Services
PureRobotics® electromagnetic condition assessment
PureRobotics® HD-CCTV inspection
Risk assessment and prioritization
Single day mobilization and inspection
Timing
2015
Pipe Material
Lined Cylinder and Embedded Cylinder Pipe (Types of PCCP)
Inspection Length
0.68 miles
Diameter
48-inch & 54-inch
Transmission Type
Recirculating Water

Project Highlights

0.68 miles (1.09kms) total distance inspected

117 pipes inspected

31 pipes with broken wire wraps

25 repaired and replaced pipes

Challenge

The lines used for recirculating water play a critical role in the operation of a steel plant. When the mill scheduled a brief operational shutdown, they wanted to quickly understand the true condition on a section of their return and supply lines in order assess and prioritize risk and rehabilitate any problem pipes.

On June 2015, the steel mill engaged Pure Technologies Ltd. (Pure) to conduct a non-destructive evaluation of the prestressed concrete cylinder pipe (PCCP) sections in the 48 inch Recirculating Water Return (RWR) and the 54-inch Recirculating Water Supply (RWS) Lines.

The inspected portion of RWR Line is composed of single wrap lined cylinder pipe (LCP). The inspected portion of RWS Line is composed mainly of single wrap embedded cylinder pipe (ECP) without shorting and a short section of single wrap LCP. The pipes were manufactured in 1981.

Pure Technologies previously inspected the 48-inch RWR Line in July 2009 and January 2010 and the 54- inch RWS Line in January 2010. To facilitate a direct comparison between past and current inspection results, the data from the 2010 inspection was reviewed to ensure data analysis continuity.

Solution

The purpose of the single day inspection was to locate and identify pipes that have broken prestressing wire wraps, using Pure’s electromagnetic inspection technology. An electromagnetic inspection provides a non-destructive method of evaluating the baseline condition of the prestressing wire, the structural component that provides the pipe’s strength.

Since the line was dewatered, the survey requirements would also include a visual inspection, which led Pure to recommend the tethered PureRobotics platform, as it is equipped with a high definition CCTV camera to deliver a live video stream from inside the pipe.

The robotic transporter is designed to carry a variety of sensors and tools and can travel a total of 2.9 kilometers from a single point of access. With the new generation of robot, the speed is doubled to 85 feet per minute, which greatly improves efficiency in the field, a huge benefit during time-critical shutdowns.

The inspection went off without a hitch, as crews from the plant had earlier prepped all access points. Pure simply set up a tripod with a chain fall, and lowered the tethered robot through a manhole into the pipe to begin the inspection journey.

Results

Overall, the survey was a low effort, little disruption inspection, conducted in less than a day.

The inspection covered a cumulative distance of 0.68 miles and spanned a total of 177 pipes.

Of these pipes, 25 are replacement pipes or have been previously repaired using carbon fibre.

Analysis of the data obtained during the inspection determined that out of the remaining 152 pipes, 8 pipes in the 48- inch RWR Line and 23 pipes in the 54-inch RWS Line displayed electromagnetic anomalies consistent with prestressing wire damage, ranging from 5 to 40 broken wire wraps.

With the actionable information delivered by Pure, the mill was able to learn about the current condition of their critical assets, and strategize rehabilitation and repair initiatives that meet the goals of their production. In the end, effective asset management using the latest tools and strategies helps reduce costs through targeted spending.

Case Study

The Milwaukee Metropolitan Sewerage District (MMSD) takes a proactive approach to water management initiatives, as evidenced in the condition assessment of the Franklin-Muskego Force Main.

Ownership of the pipeline is shared between the City of Muskego and MMSD, the government agency that provides water management services for about 1.1 million people in 28 communities in the Greater Milwaukee Area.

In 2015, Pure Technologies (Pure) worked closely with MMSD to perform a detailed condition assessment of the approximately 25-year old ductile iron pipeline. The purpose of the assessment was to identify the structural condition of the metallic force main, and included pressure monitoring, a SmartBall® leak and gas pocket detection survey, and a PipeDiver® electromagnetic inspection of the pipeline.

Project Details

Services
SmartBall® Leak and Gas Pocket Detection
PipeDiver® Electromagnetic Inspection
Transient Pressure Monitoring
Structural Engineering
Timing
2015
Pipe Material
Ductile Iron
Inspection Length
2.9 miles (4.7 kms)
Diameter
20-30 inches (500-750mm)
Transmission Type
Wastewater

Project Highlights

Inspection identified 13 pipe sections with electromagnetic anomalies

Defects ranged from 20-55% wall loss

Transient pressure monitoring indicated pipeline operating within design capacity

Challenge
The Franklin-Muskego Force Main carries wastewater along approximately 3 miles of 24-inch and 30-inch ductile iron pipe (DIP). One of the challenges in assessing DIP is determining if the pipe has undergone any wall thickness loss due to internal or external corrosion, which are the primary causes of failure. DIP in water service with a cement mortar lining generally has fewer internal corrosion failure rates, unless damaged during handling and installation, or later as a result of 3rd party damage. This is not the case when DIP is used in a force main, where internal corrosion is the primary cause of failure.

Gas pockets are of significant concern as concentrations of hydrogen sulfide gas within wastewater may cause corrosion and eventual breakdown of the pipe’s exposed surface. In a force main, identifying internal areas with potential corrosion is challenging, as traditional gravity pipeline inspection techniques are often not applicable to in-service pressurized pipelines.

One method for assessing gas pockets is to locate air release valves (ARVs) or other high points along the alignment and conduct test pit investigations in those areas. While this is a valid method for locating potential gas pocket locations, additional gas pockets may occur due to differential settlement, improper installation or non-functioning ARVs. Desktop surveys may not identify and locate all gas pockets along a pipeline, which is why Pure recommends other more precise survey methods.

Solution
To evaluate the condition of the Franklin-Muskego force main, Pure recommended in-line condition assessment. This included inspecting for the presence of gas pockets, using electromagnetics for assessing the condition of the pipe wall and structural engineering to evaluate the significance of defects found.

In October 2015 Pure performed a SmartBall leak and gas pocket detection survey and a PipeDiver electromagnetic inspection of the Franklin-Muskego Force Main. The SmartBall platform is a free-swimming tool that uses acoustics to detect leaks and gas pockets while the pipeline remains in full service. Pure’s flexible, free-swimming PipeDiver tool collects electromagnetic (EM) data that is used to measure the relative wall thickness of the cylinder – the main structural component of the pipeline. With electromagnetics onboard, PipeDiver can identify localized areas of wall loss in the cylinder of the pipe, and broken bar wraps in BWP, all while the pipeline remains in service.

Results
The results of the C150 design check showed that the pipe’s nominal wall thickness is sufficient for current loading conditions. Transient pressure monitoring indicated that over the period of monitoring, the pipeline operated within its design capacity.

Through the PipeDiver inspection, 13 pipes were found to have a total of 16 electromagnetic anomalies consistent with localized wall loss, ranging between 20 percent to 55 percent wall loss. At the time of writing, MMSD was making plans to excavate and repair one pipe section with three areas of pipe loss ranging from 35 percent to 55 percent wall loss. The results of the condition assessment indicate that the Franklin-Muskego Force Main is in good condition.

While the assessment recognized several areas with an increased likelihood of failure, overall the data was good, and coupled with Pure’s engineering recommendations, gave all stakeholders confidence in the health of pipeline for the near foreseeable future.

Case Study

Following a water main break in 2009 that resulted in the loss of 15 million gallons of treated water, LWC began a Transmission Assessment Program, using various assessment technologies from Pure Technologies.

Project Details

Services
PureRobotics® electromagnetics (EM) condition assessment

PureRobotics HD-CCTV inspection

Inertial measurement unit for GIS component

Risk prioritization

Timing
2015
Pipe Material
PCCP
Inspection Length
3.4 miles (5.5 kms)
Diameter
24-30 inches (610-760mm)
Transmission Type
Water

Project Highlights

EM data identified 17 anomalies warranting further investigation

HD-CCTV identified longitudinal cracks consistent with overloading

One (1) pipe section found to display anomalous EM signals associated with broken wire wraps and wall cylinder loss

Challenge
In the summer of 2015, LWC deployed PureRobotics to assess 3.4 miles of 24 to 30-inch transmission mains in its network. With 4,100 miles of pipeline to maintain, (200 miles of it transmission main) LWC focused its condition assessment on its transmission main system – pipes that would cause the greatest amount of damage in the case of failure. The loss of non-revenue water, either chronically in small amounts or from a catastrophic failure, can result in massive costs to a water utility.

By prioritizing the risk levels associated with their transmission main system, LWC has created an ongoing inspection program to keep a watchful eye on the health of their pipelines. The program utilizes a number of Pure Technologies assessment tools to find active leaks as well as potential future threats.

Solution
In May of 2015, PureRobotics was deployed on the Cross County Header, Ray Lane Easement Pipeline, and Bardstown Road Pipelines. The latest generation robotic crawler is designed to carry sensors and tools up to 1.8 miles (2.9 kilometers) through potable water or wastewater at a speed of 85 feet per minute. For LWC, PureRobotics used CCTV to provide a comprehensive high-definition visual inspection.

The robotic crawler was also outfitted with specialized tools to conduct an electromagnetic assessment on the condition of the pipeline and inertial measurement unit (IMU) for the GIS component. The Inertial Measurement Unit (IMU) deployed with PureRobotics uses a series of Fiber Optic Gyroscopes (FOGs) and accelerometers to track depth, lateral and horizontal movements from a known GPS reference point. The output is a GIS spatial map of the pipeline which depicts elevation changes as well as notable features of interest encountered during the inspection.

Pure’s electromagnetic assessment uses transformer coupling to detect anomalous regions in the pipe cylinder and prestressing wires. This data is correlated with odometer readings from the PureRobotics umbilical tether as well as HD recorded CCTV and IMU to attempt to locate areas of distress in the pipeline.

Results
High definition CCTV inspection results showed a number of longitudinal cracks consistent with overloading. These types of mortar cracks may eventually lead to corrosion of the steel cylinder or prestressing wire and eventually a failure of the pipe.

One pipe section in the Ray Lane Easement pipeline was found to display anomalous electromagnetic signals showing a significant number of broken prestressing wire wrap breaks as well as cylinder wall loss. This was correlated with visual data, showing spalling and exposed steel at the invert of the pipe. LWC intends to investigate this issue at a later date.

Visual assessment also showed a number of pipe sections with spalling. Pure recommended continued monitoring at these locations during future inspections. Electromagnetic assessment also found 11 pipes with anomalous signals not consistent with wire breaks. Investigation performed on one of these anomalous pipes showed a non-standard metal sleeve used in manufacturing. From this information, it was determined that the remaining 10 anomalous pipes could be left in service.

As one of the first utilities to deploy the third generation PureRobotics platform, LWC now has defensible data to move forward with its ongoing rehabilitation program.

Case Study

The City of Calgary provides water and wastewater services for more than 1 million people in the Greater Calgary area. For many municipalities, accurate and regular condition assessment of large-diameter pressure pipelines has become more important in recent years as these assets continue to age and risk of failure increases.

In Calgary, three critical feedermains (14th Street/North Hillhurst, John Laurie and Top Hill) are each constructed of different materials: lined cylinder pipe (LCP), prestressed concrete cylinder pipe (PCCP) and bar wrapped pipe (BWP). The pipes range from 750mm (30-inch) to 900mm (35- inch) in diameter.

Project Details

Services
PureRobotics® electromagnetic condition assessment

PureRobotics® HD-CCTV inspection

Risk Prioritization

Timing
2015
Pipe Material
PCCP, LCP, BWP
Inspection Length
4.74 km (2.9 miles)
Diameter
750mm-900mm (29-35 inch)
Transmission Type
Water

Project Highlights

Condition assessment on 2.92 miles (4.7 kms) of feedermain pipes

Data identified 8 pipes with electromagnetic anomalies consistent with broken pressing wire wraps

HD-CTTV identified 3 pipes with damaged internal mortar and exposed cylinder

Challenge
In an annual condition assessment program, The City inspects its PCCP, BWP and LCP for deterioration. By identifying isolated pipe sections with deterioration, the City is able to make selective repairs in favor of full-scale replacement, which comes at a high cost and may replace sections with significant remaining useful life.

In data collected from more than 14,000 miles of pressure pipe condition assessment, Pure Technologies has found that only a small percentage of pipes (less than 5 percent) are in need of repair and therefore have years of service left. Condition assessment data also suggests that pipe distress is localized, and significant ROI can be achieved by locating and addressing isolated problems through structural inspection.

Solution
To inspect the three feedermains, the City deployed PureRobotics®, a tethered robotic system that delivers live video, and is equipped with electromagnetic technology that can be configured to inspect a variety of pipelines and materials with different operational conditions.

In BWP, the technology identifies and locates broken bars and areas of corrosion on the steel cylinder, which are the main indication this type of pipe will eventually fail. Although BWP looks similar to PCCP in cross section, the design and materials are significantly different.

PCCP is a concrete pipe that remains under compression because of the prestressing wires, with the thin-gauge steel cylinder acting as a water membrane. With BWP, the cylinder plays a much larger role in the structural integrity of the pipe. BWP is essentially designed as a steel pipe with mild steel used to manufacture the steel cylinder and steel bars. PCCP utilizes mild steel for the cylinder, but high strength steel is utilized for the wire, which is wrapped under high tension. As a result, the bar in BWP and wire in PCCP respond differently to environmental conditions that facilitate corrosion.

The high strength steel wire in PCCP is smaller in diameter and wrapped under higher tension, therefore corrosion makes it quite vulnerable to breakage. The mild steel bars in BWP are thicker in diameter and wrapped under less tension, therefore corrosion takes significantly longer to lead to breakage. The type of failure is also much different; PCCP tends to fail suddenly with a large dispersion of energy. This type of failure is less likely in BWP where failures are similar to steel pipe with long periods of leakage occurring prior to rupture. Because of the differences in make-up, BWP and PCCP are inspected using unique methods to determine their structural condition.

Results
Of the 694 pipes cumulatively inspected over the 4.74 kilometers, eight (8) pipes were identified with electromagnetic anomalies consistent with broken prestressing wraps. Additionally, two (2) pipes were found with an anomalous signal not characteristic of broken bar wraps that can be attributed to a change in the pipe cylinder.

Evaluation of the John Laurie Boulevard Feedermain concluded that one (1) pipe was identified to have an anomalous signal likely caused by a non-uniform cylinder. Images obtained from the robot indicated this pipe has damaged internal mortar and exposed cylinder. Additionally, two (2) pipes on this feedermain were identified to have damaged internal mortar and exposed cylinder, but did not contain anomalous signals.

The City of Calgary was pleased with the results, and through condition assessment, has been able to identify and address individual distressed pipe sections on otherwise serviceable feedermains. This has allowed the City to avoid potential ruptures, while increasing service reliability and useful life of the feedermains.

For utilities with large-diameter networks, waiting for failures to occur before repairing or replacing highly critical mains is not an option.

Massive pressured water lleak on a street

With a large amount of buried water infrastructure reaching the end of its service life, operators have every incentive to take a proactive approach to asset management.

Nowhere is this more critical than in busy urban centres. The fallout from an unexpected failure can have major societal costs, and greatly diminish public confidence in the utility.

Asset management begins with condition assessment

Successful asset management begins with condition assessment, the point at which problems and challenges are understood and shaped into definitive plans from both an operational and financial perspective.

To proactively address their pipeline conditions, operators today have access to variety of tools, technologies and engineering analysis that allow for a comprehensive condition assessment of large-diameter pressure pipes, for both water and wastewater systems.

“Unfortunately there is no ‘silver bullet’ with regard to condition assessment technologies,” said Mike Wrigglesworth, Senior Vice President of Pure Technologies. “Each pipeline is unique, and no single technology is the fix for all situations. A combination of factors, from pipe material to soil conditions, operational challenges, age, installation and third party factors will all play a role in the likelihood of failure. Combined with the consequence of failure, a risk-based approach can then be used to select the best condition assessment tool or technologies.”

Matching assessment technology with the pipeline conditions and project goals

While operators can now deploy a number of data-based tools and techniques to assess pipeline conditions, each technology also comes with varying degrees of limitation. For instance, while magnetic flux leakage (MFL) tools provide the highest resolution data for steel pipe, MFL is of limited value for concrete pipe.

Medium resolution techniques such as electromagnetics can identify localized areas of wall loss on metallic pipes such as ductile iron and steel, but not on cast iron pipe as cylinder thickness is often too thick and material properties vary considerably, negatively affecting results. In both cases, it is often prudent to deploy leak detection technologies, as studies show joint defects lead to leaks, and leaks are precursors to failure.

“Often the best solution is to use different but complementary technologies to collect robust condition data that is then evaluated using engineering analysis against a comprehensive risk of failure versus a consequence of failure analysis.”

Sahara® Leak and Gas Pocket Detection

Pure’s proprietary Sahara® inspection platform is a tethered, multi-sensor tool that can identify acoustic-based leaks, gas pockets and visual anomalies in real time, with no disruption to service.

The Sahara tool features a small parachute that uses the product flow to draw the sensor through the pipeline while being controlled from the surface.

SmartBall® Leak and Gas Pocket Detection

SmartBall® is a multi-sensor tool used to identify a variety of conditions in pressurized pipelines. The tool is easy to deploy through existing pipeline features, and travels untethered with the product flow, collecting information.

The tool’s highly sensitive acoustic sensor can locate small leaks and gas pockets, with typical location accuracy within 6 feet (1.8 m).

PipeDiver® Condition Assessment

PipeDiver® is a free-swimming condition assessment tool that operates while the pipeline remains in service.

Originally designed for use in PCCP, the tool has electromagnetic sensors to identify and locate broken prestressing wire wraps. For metallic pipelines, the optimized PipeDiver has the ability to pinpoint localized areas of wall loss.

The tool is also able to deliver video images from inside the pipe.

PipeWalker™ Condition Assessment

The PipeWalker tool provides a viable option for pipeline condition assessment in situations where the pipe is dewatered or where the option to dewater is available.

The tool is equipped with electromagnetic sensors for detecting wire wrap breaks on PCCP pipes and for detecting corrosion on metallic pipes.

PureRobotics® Pipeline Inspection

PureRobotics® is a depth-rated robotic pipeline inspection system that can be configured to inspect pipe applications 24-inches and larger.

Tethered by a high-strength fiber optic cable, the crawler is capable of performing multi-sensor inspections in dewatered pipes or while submerged in depressurized pipes.

The crawler features HD digital CCTV, and can be equipped with electromagnetic sensors, Inertial Mapping, 3-D LIDAR, LASER, SONAR and other tools upon request.

Matching the level of resolution to the risk of the line

While there are a variety of approaches available for assessing a pipeline’s condition, much of an operator’s effort must go into matching the level of resolution of the approach to the overall risk of the line.

The idea is to put the highest resolution technologies on the most critical lines. In the end, the goal of deploying a particular technology (or complementary technologies) is to identify and locate the areas that need rehabilitation or repair as opposed to wholesale replacement of those lines.

Armed with the right information, operators can determine remaining useful life, and confidently move forward to prioritize and target capital spending, while avoiding failures.

The first time new parties come together to work on a pipeline inspection project, they face a lot of pressure to perform.

The team must instill trust and understand each other to ensure the project goes off without a hitch. In this instance, that’s what happened when Pure Technologies (Pure) and its long-time partner WRc came together with;Irish Water, Cork County Council (CCC) to assess and address the condition of a critical water main in the City of Cork, Ireland.

As this was the first collaborative project among the four groups, it was also a test of the planning expertise, engineering skills and technology advances for Pure Technologies and WRc to impress upon Irish Water and Cork County Council. In the end, the inspection was successful, lessons were learned, and a positive new relationship was forged.

Aerial view of the City of Cork

Project Begins With Six Months of Planning

After six months of planning, in March 2017, Irish Water and its consultant WRc engaged Pure Technologies to conduct a non-destructive evaluation of approximately six (6) kms (3.7 miles) of 1500mm (60-inch) and 1200mm (48-inch) prestressed concrete cylinder pipe (PCCP) sections in the water main between Chetwynd reservoir and Carrs Hill, using the SmartBall® pipeline inspection platform.

 

 

SmartBall tool provides acoustic signature related to leaks and gas pockets

For the Inniscarra Water Main inspection, Pure Technologies deployed its proprietary SmartBall technology, a multi-sensor tool used to detect and locate the acoustic signature related to leaks and gas pockets in pressurized pipelines. The tool has the ability to inspect long distances in a single run, and while the SmartBall is deployed, the pipeline remains in service, limiting disruption to customers.

Unlike traditional listening tools like correlators, which have limited success on large diameter pipes, the free-flowing SmartBall technology provides a high degree of accuracy, because as the device travels along the pipeline, it continuously records the acoustic environment within the line. All data is stored onboard the device and later evaluated to determine the presence and location of any leaks or pockets of trapped gas.

Tool tracked at known points along the pipeline alignment

 

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

From insertion to extraction, the SmartBall inspection took a little over six hours, with no unexpected events that were not anticipated during the planning stage.

As the SmartBall was extracted, it was met with a round of roaring applause from assembled team members.

Results lead to effective management of finances and risk

Based on the inspection data, our analysts reported three (3) anomalies characteristic of leaks, and zero (0) acoustic anomalies characteristic of pockets of trapped gas.

Overall, both Irish Water and Cork County Council were pleased with the project results, as they were able to understand the overall condition of the pipeline and make an informed decision for capital improvements of the Inniscarra Water Main. The project demonstrates how Irish Water and CCC can use actionable data to effectively manage their finances and risk, while continuing to provide the community with a safe and reliable delivery of drinking water.

 

A growing number of proactive municipal utilities and power generating operators across North America are reaping the benefits of deploying the latest robotics crawler from Pure Technologies (Pure) to assess the condition of their pipeline networks and save millions of dollars in water loss and prevented breaks.

Unlike slower, limited-distance crawlers, the third generation robotic transporter can quickly navigate up to 1.8 miles (2.9 kilometres) through potable water with ease, and deliver live video and integrity information that can aid in detecting leaks and other anomalies in underground pipes. Since introduction, the latest PureRobotics® platform has delivered data over more than 186 miles (300 km) of pipe and has been deployed for clients including Austin Water Utilities, The City of Ottawa, City of El Paso and Louisville Water.

“We absolutely crushed our previous distance covered in a single day…”

The rollout of our latest generation robot will deliver additional benefits to our clients by providing detailed, real-time, internal condition data in about half the time as the previous generation,” stated Mark Holley, Executive Vice President and Chief Operating Officer of Pure Technologies. “This will reduce our inspection time and correspondingly reduce any facility downtime. In addition, the modular design allows us to customize tools to inspect a broader variety of pipeline sizes and types.


Robot's faster speed important for time-critical shutdowns

 

The PureRobotics pipe inspection system is a modular transporter designed to carry sensors and tools through dewatered pipe or while submerged in depressurized pipes. The advanced robotic crawler is safer than manned inspections, especially where regulations are keeping people out of pipelines in favour of unmanned solutions.

With the new generation of robot, the speed is doubled to 85 feet per minute, which greatly improves efficiency in the field, a huge benefit during time-critical shutdowns.

The standard system features HD digital, pan tilt zoom, closed circuit television for live video streams. The robot can be equipped with a variety of specialized tools including an inertial measurement unit for XYZ mapping geographic information, 3-D LIDAR scanning tools, electromagnetic sensors for assessing the structural integrity of pipelines, or pull condition assessment tools such as 2-D laser technology that can precisely measure a pipeline’s size, shape and level of corrosion.

 

PureRobotics deployed on reclaimed water line for nuclear plant

 

Recently the latest generation PureRobotics platform was deployed during a multi-tool inspection for a reclaimed water line operated by a major U.S. nuclear plant.

Since 1998, the plant has assessed its reclaimed water pipeline using electromagnetic technology(EM) from Pure Technologies to ensure the station continues to operate safely. The inspections cover prestressed concrete cylinder pipes (PCCP) that range from 96 inches to 144 inches in diameter.

The EM inspections are typically performed using the PureRobotics™ delivery platform, or by using manned inspection tools so the pipeline can be visually inspected as well. Electromagnetic inspection provides high quality condition assessment data for understanding the structure integrity of large-diameter pressure pipelines. For the nuclear plant, it is used to assess the number of broken prestressing wire wraps on the PCCP pipeline.

During the latest scheduled EM inspection conducted in 2017, Pure deployed its latest generation robotic crawler.

Robotic crawler beats record and delivers 18,000 feet of condition data in single day

 

What made the inspection so remarkable was the speed of the robot and inspection distance covered during the time-critical shutdown. The inspection set a record for distance covered in a daily inspection, upwards of 18,000 feet of condition assessment footage delivered per day, compared to previous record of 11,000 feet. The robotic inspection covered total distance of nearly 14 miles.

We absolutely crushed our previous distances covered in a single day,” said James Milward, lead developer for the robotic crawler. “The conditions were right, and because we leapfrogged the access points, we finished way ahead of schedule. When you’ve only got a small window of inspection time during a scheduled shutdown, any time saved is a bonus for the client. They were very happy with the outcome.

Good data, faster inspection times, better efficiency, no hiccups, you couldn’t ask for a better inspection project.

It’s a major event when you’ve been asked to perform a first in terms of a pipeline inspection.

For starters, you must feel confident in the inspection technology you recommend. Second, you hope that all your planning for deployment and unexpected contingencies has been anticipated. And finally, with so many eyes focused on the outcome, you hope the first inspection of its kind goes off without a hitch.

That was the case in May 2017, when the Dutch utility Brabantse Delta retained Pure Technologies (Pure) to perform a SmartBall® inspection on a critical untreated wastewater pipeline near the city of Zevenbergen, located in the North Brabant province.

For Pure Technologies, this project marked the first SmartBall acoustic inspection of a rising [force] main in the Netherlands.

Brabantse Delta operates AWP-1, a pre-stressed concrete cylinder pipe (PCCP) pipeline that transfers industrial wastewater from the Moerdiijk pump station to the Hoven pump station. The 800mm (32-inch) pipeline traverses a lot of farmland near the city, which made accessing buried manholes somewhat of a challenge, as many of these were located on private land, making excavation difficult.

Gas pockets are of concern on wastewater lines

The pipeline has not experienced regular failures, but Brabantse Delta was looking for solutions to establish a baseline condition and manage the risk of this critical asset. The primary purpose of the SmartBall inspection was to identify and locate leaks and pockets of trapped gas along the approximately 8.3 km (5.1 mile) pipeline.

We were pleased the overall execution and excited that the SmartBall tool was able to collect inspection data while the force main remained in operation.” Ing. R van Wanrooij, Adviser Civil Engineering, Brabantse Delta

Gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks and gas pockets and for its ability to inspect long distances in a single deployment. Minimal pipeline modifications are required for insertion and extraction.

SmartBall tool tracked at known points along the pipeline alignment

The free-swimming, acoustic-based SmartBall® tool is inserted into the pipeline flow, and after traversing the inspection length, the tool is captured and extracted at a point downstream.

During inspection, the SmartBall tool’s location is tracked at known points along the length of the pipeline to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

Unlike traditional listening tools like correlators, which have limited success on large diameter pipes, the free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls inside the pipe, it can inspect every inch of the main to detect leaks and gas pockets.

Prior to the execution of the project, Pure Technologies reviewed the site and all pipeline drawings. The only real inspection challenge was taking into account the limited number of SmartBall receiver tracking units, as some of the buried manholes were located on private farms.

Inspection results

The inspection went smoothly, and all data successfully collected. From insertion to extraction, the SmartBall inspection took under 5 hours, with no unexpected events thanks to cooperative planning and full support of the Brabantse Delta team.

Preliminary data indicated no leaks and zero (0) acoustic events associated with pockets of trapped gas. Entrained air was present throughout the pipeline, but no events of significance were detected. Entrained air is a migratory event, meaning its location is dynamic and changes over time with the operational flow. These events are expected to move throughout the pipeline, and locations are specific to the time of the inspection.

Overall, Brabantse Delta was pleased with the execution, and excited to know there was an inspection tool that gave them a better understanding on the overall condition of the AWP-1 pipeline. The project demonstrates how Brabantse Delta uses actionable data to effectively manage risk, while continuing to provide the community with a safe and reliable delivery of untreated wastewater.

State of the Water Industry Report 2017

The American Water Works Association (AWWA) has formally tracked issues and trends in the water industry since 2004 through its State of the Water Industry (SOTWI) study. The Association continues to conduct this annual survey in order to:

  • Identify and track significant challenges facing the water industry
  • Provide data and analysis to support water professionals as they develop, implement, and communicate strategies to address current and future issues
  • Inform decision makers and the public of the challenges faced by the water industry
“Water professionals are feeling overwhelmed,” said AWWA president-elect, Brenda Lennox. “A perfect storm of issues is coming together. Crumbling infrastructure is overwhelming enough, but we’re also experiencing huge workforce turnovers and feeling the backlash of that.”

Top Issues

The top five most important issues facing the water industry were identified as follows:

  1. Renewal and replacement (R&R) of aging water and wastewater infrastructure (#1 in 2016)
  2. Financing for capital improvements (#2 in 2016)
  3. Long-term water supply availability (#4 in 2016)
  4. Public understanding of the value of water systems and services (#3 in 2016)
  5. Public understanding of the value of water resources (#5 in 2016)

Case Study

K-water, the national bulk water utility in South Korea, supplies water across the country to smaller cities and controls everything from collection, treatment and pumping to maintenance, inspection and rehabilitation of the nation-wide pipeline system.

In addition to supplying treated water to these small cities, many have contracted K-water to manage and maintain their distribution systems as they battle the challenges of aging infrastructure. Beginning in 2011, K-water has used Sahara® Leak Detection to address non-revenue water and collect condition information about its metallic pipelines.

Project Details

Services
Sahara® Leak Detection
NRW reduction program
Baseline condition assessment
Timing
2012-ongoing
Pipe Material
Steel, Cast Iron, Ductile Iron
Diameter
6-inch (150mm) to 90-inch (2300mm)
Transmission Type
Water

Project Highlights

22 leaks located in 25 miles (40.23 kms) of inspection

Pinhole leaks identified within 5 cm of actual location

Estimated 350,400 m3 of water saved per year in Tongyeong City

Challenge

In 2009, K-water was searching for a large-diame­ter leak detection tool for its critical trunk mains. While K-water has done an exemplary job of maintaining its nation-wide pipeline network, which totals about 5,000 kilometers and has a Non-Revenue Water (NRW) rate of about 2 per­cent, many of its client municipalities suffer from high levels of NRW as their infrastructure ages and begins to leak. K-water was also interested in a tool that would allow them to compare actual pipeline conditions with their extensive pipeline engineering knowledge, allowing for quality con­dition assessment and failure prevention. In 2011, K-water began a knowledge-transfer program with Pure Technologies to become independent operators of Sahara leak detection.

Solution

K-water has built up expert knowledge in pipe­line engineering, a database of information on their pipe materials and pipe failure methods, and has adopted the best condition assessment technologies in the market to help inspect their pipelines so that efficient, prioritized rehabilita­tion and replacement plans can be made.

One condition assessment tool K-water has adopted is the Sahara platform – a tethered system with acoustic leak detection and inline video. While many utilities around the world use this tool for large-diameter leak detection, K-wa­ter has adopted it in an innovative way, choosing to use it as a complete condition assessment tool to provide information on its pipelines and accu­rate location of leaks.

The tool is non-destructive and is pulled by the flow of water by a small drag chute. When the sensor is inserted into a tap, it remains tethered to the surface to allow for immediate checking of suspected leaks and gas pockets, internal pipe wall conditions and pipeline features by winching the sensor back and forth from the surface. The sensor is also tracked at ground level by a staff member, allowing for precise spot markings for excavations. Sahara also provides real-time inline video, which allows the operator to see live pipe conditions as the tool surveys for leaks and gas pockets.

Operating with a national mandate and several stakeholders, K-water faces a number of logistical challenges with its pipeline infrastructure.

One challenge is population density; South Korea is roughly 2 per cent of the size of Canada with almost double the population, meaning large, densely populated regions rely on K-water for consistent water service. A failure or service interruption to a critical trunk main could be disastrous K-water’s credibility with customers.

South Korea is also a very mountain­ous region, meaning pipelines supplying water throughout the country often pass through areas that are difficult to inspect using traditional methods. In addition to the landscape, many of K-water’s large diameter pipelines are buried deep in the ground, making excavation projects com­plex and expensive to complete.

By becoming certified Sahara tool operators, K-water staff can deploy the tool at their own descretion and are able to overcome these chal­lenges to complete inspections in difficult regions.

Results

Tongyeong City, South Korea, which has a high NRW and features 32-inch (800-mm) steel pipe, has been inspected twice; first as part of Pure’s Sahara training program and subsequently by K-water as an independent operator. The inspec­tions in Tongyeong City were extremely success­ful, locating 10 total leaks with high accuracy in 2.5 kilometers of inspection for an estimated sav­ings of 350,400 cubic meters of water per year.

During the training inspections, Pure and K-wa­ter were able to locate pinhole leaks as close as 5-cm above and below the actual leak location – meaning service disruption, excavation and repair times were minimal. In K-water’s subsequent inspection of the same pipeline in Tongyeong City, they were able to excavate and repair all three identified leaks in 5.5 hours each during the night (3 separate repairs), causing little disruption to customers.

In total, K-water has inspected 25 kilometers of pipeline and located 22 leaks of varying sizes. K-water has inspected both its own pipelines as well the regional pipelines that it operates and has covered pipes with diameters as small as 150-mm and as large as 2300-mm, with most pipe being either steel, ductile iron or cast iron pipe. K-water’s 2012 program will cover about 52 kilometers of pipeline for leaks and gas pockets

While the tool has been effective in locating leaks for K-water, its value as a complete condition assessment tool has also been helpful due to the unique challenges faced in South Korea. K-water has been able assess the state of its pipelines by combining the inline video data and its extensive engineering knowledge. By doing this, K-water has become a thought-leader in large-diameter pipeline management.

K-water has successfully applied the Sahara platform for condition assessment in its transmission mains and for leak detection in municipal trunk mains.

Se-Hwan Kim

General Manager, Water Supply Operation & Maintenance Department, K-water

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Case Study

The Milwaukee Metropolitan Sewerage District (MMSD) takes a proactive approach to water management initiatives, as evidenced in the recent condition assessment of the Franklin-Muskego Force Main.

In 2015, Pure Technologies (Pure) worked closely with MMSD to perform a detailed condition assessment of the approximately 25-year old ductile iron pipeline. The purpose of the assessment was to identify the structural condition of the metallic force main, and included pressure monitoring, a SmartBall® leak and gas pocket detection survey, and a PipeDiver® electromagnetic inspection of the pipeline.

Project Details

Services
SmartBall® leak and gas pocket detection

PipeDiver® electromagnetic inspection

Pressure monitoring

Structural engineering

Timing
2015
Pipe Material
Ductile Iron
Inspection Length
2.9 miles
Diameter
20-inch to 30-inch
Transmission Type
Wastewater

Project Highlights

Condition assessment on

4.7km

of feedermain pipes

Data identified

8

pipes with electromagnetic anomalies consistent with broken pressing wire wraps

HD-CTTV identified

3

pipes with damaged internal mortar and exposed cylinder

Challenge

The Franklin-Muskego Force Main carries wastewater along approximately 3 miles of 24-inch and 30-inch ductile iron pipe (DIP).

One of the challenges in assessing DIP is determining if the pipe has undergone any wall thickness loss due to internal or external corrosion, which are the primary causes of failure. DIP in water service with a cement mortar lining generally has fewer internal corrosion failure rates, unless damaged during handling and installation, or later as a result of 3rd party damage.

This is not the case when DIP is used in a force main, where internal corrosion is the primary cause of failure. Gas pockets are of significant concern as concentrations of hydrogen sulfide gas within wastewater may cause corrosion and eventual breakdown of the pipe’s exposed surface.

In a force main, identifying internal areas with potential corrosion is challenging, as traditional gravity pipeline inspection techniques are often not applicable to in-service pressurized pipelines.

One method for assessing gas pockets is to locate air release valves (ARVs) or other high points along the alignment and conduct test pit investigations in those areas. While this is a valid method for locating potential gas pocket locations, additional gas pockets may occur due to differential settlement, improper installation or non-functioning ARVs.

Desktop surveys may not identify and locate all gas pockets along a pipeline, which is why Pure recommends other more precise survey methods.

Solution

To evaluate the condition of the Franklin-Muskego force main, Pure recommended in-line condition assessment. This included inspecting for the presence of gas pockets, using electromagnetics for assessing the condition of the pipe wall and structural engineering to evaluate the significance of defects found.

In October 2015 Pure performed a SmartBall leak and gas pocket detection survey and a PipeDiver electromagnetic inspection of the Franklin-Muskego Force Main.

The SmartBall platform is a free-swimming tool that uses acoustics to detect leaks and gas pockets while the pipeline remains in full service.

Pure’s flexible, free-swimming PipeDiver tool collects electromagnetic (EM) data that is used to measure the relative wall thickness of the cylinder – the main structural component of the pipeline. With PureEM® onboard, PipeDiver can identify localized areas of wall loss in the cylinder of the pipe, and broken bar wraps in BWP, all while the pipeline remains in service.

Results

The results of the C150 design check showed that the pipe’s nominal wall thickness is sufficient for current loading conditions. Transient pressure monitoring indicated that over the period of monitoring, the pipeline operated within its design capacity.

Through the PipeDiver inspection, 13 pipes were found to have a total of 16 electromagnetic anomalies consistent with localized wall loss, ranging between 20 percent to 55 percent wall loss. At the time of writing, MMSD was making plans to excavate and repair one pipe section with three areas of pipe loss ranging from 35 percent to 55 percent wall loss.

The results of the condition assessment indicate that the Franklin-Muskego Force Main is in good condition.

While the assessment recognized several areas with an increased likelihood of failure, overall the data was good, and coupled with Pure’s engineering recommendations, gave all stakeholders confidence in the health of pipeline for the near foreseeable future.

Case Study

The Foothill Municipal Water District (FMWD) serves approximately 86,000 people through its member agencies located in the foothills of the San Gabriel Mountains, bordered between the City of Pasadena and the City of Glendale. In March 2013, Pure Technologies (Pure) successfully completed in La Canada Flintridge, a 2.2-mile internal inspection and condition assessment of a 24-inch mortar-lined steel force main to identify broad areas of wall loss.

Project Details

Services
PureRobotics™ electromagnetic condition assessment inspection

PureRobotics HD-CCTV inspection

Structural assessment

Engineering services

Risk prioritization

Timing
2013
Pipe Material
Mortar-lined Steel
Inspection Length
2.2 miles (3.55 km)
Diameter
24-inch (610-mm)
Transmission Type
Water

Project Highlights

EM data identified 17 anomalies warranting further investigation

FMWD selected 2 locations to perform test pitting

Results revealed minimal wall loss and continued operation of water main

Challenge

For utilities like FMWD, which has no redundancy in its system, finding a reliable inspection method that provides condition data for the entire length of a steel pipeline is an important aspect of its condition assessment program.

As well, as part of the condition assessment, a structural evaluation was performed to determine whether the force main design satisfies AWWA M11 “Steel Pipe – A Guide for Design and Installation, fourth edition” standards. The results of this evaluation has helped FMWD determine where to focus more detailed inspections in order to make detailed rehabilitation decisions for this force main.

Solution

To complete the inspection, FMWD used PureRobotics electromagnetic condition assessment equipped with electromagnetic technology and high-definition closed circuit television (HD-CCTV). The platform is a non-destructive, in-line assessment tool that provides screening level wall thickness data in the circumferential and axial directions of metallic pipelines.

The robotics tool used was assembled inside the pipeline and controlled remotely by operators on ground level. This allowed FMWD to maximize the HD-CCTV function as internal features could be closely inspected with the camera. By opting for an inline assessment in favor of traditional metallic inspection methods, FMWD has a baseline condition of the entire 2.2-mile water main.

Results

After reviewing the electromagnetic data, Pure Technologies was able to identify 17 electromagnetic anomalies that warrant additional investigation. Using the resulting information, the top 10 anomalies were ranked based on the strength, area and repeatability of signal loss and visually using HD-CCTV.

FMWD selected two locations to perform test pitting to obtain higher resolution data needed to evaluate rehabilitation or repair needs and determine the remaining useful life of the water main.

Results of the two test pits revealed minimal wall loss and resulted in the continued operation of the steel water main with no rehabilitation required. Ranking the anomalies based on size allowed the prioritization of further inspection based on sound and defensible engineering judgment.

Risk prioritization is an important facet of any condition assessment program because it allows the most urgent needs to be addressed first. By proactively managing its pipeline assets, FMWD is able to continue to deliver quality water to its member agencies in a cost-efficient manner to meet their projected demands.

Case Study

Evides Watercompany was open to exploring new ways to reduce risks and extend the service life of their buried infrastructure. In particular, Evides wanted to assess the condition of its TL2.60 pipeline, a cement-lined 800mm (31.5 inch) steel pipe, with 2.8 kilometers (1.7 miles) of the inspected pipeline running along an important highway connecting Rotterdam to The Hague.

To assist in the condition assessment, Evides elected to deploy the 24-sensor PipeDiver®, an innovative tool from Pure Technologies designed to assess and address large-diameter metallic pipelines.

Project Details

Services
SmartBall® leak detection

PipeDiver® condition assessment

Timing
2016
Pipe Material
Steel
Inspection Length
2.84 km (1.7 miles)
Diameter
800mm (31.5-inch)
Transmission Type
Water

Project Highlights

 

Four (4)
pipes identified with anomalies

60% wall loss
on one pipe section identified by EM data

Zero (0)
leaks detected

 

HD-CTTV identified
estimated savings due to inspection: 1.1M Euros

 

Challenge
Prior to inspection, Evides created a series of predetermined defects made on a specific pipe segment in a research environment. The objective was to validate the tool against a range of known defects in a pipe with the same characteristics as the pipe inspected. During this process, all defects within the stated sensitivity were detected by the 24D PipeDiver tool at the precise location, providing confidence for the upcoming live inspection.

PipeDiver is a flexible, free-swimming condition assessment tool for pressurized water and wastewater pipelines. The video-equipped tool is ideal for critical pipelines that cannot be removed from service due to a lack of redundancy or operational constraints.

Solution
While PipeDiver has traditionally been deployed on prestressed concrete pipe to identify and locate broken prestressing wire wraps, the 24-detector PipeDiver has been specifically developed for metallic pipelines. For the Evides inspection, the PipeDiver tool with 24 electromagnetic sensors was used to locate and identify steel pipes with anomalies associated with corrosion or reduced wall thickness.

This Evides inspection marked the first condition assessment of metallic pipe using the 24D PipeDiver in Europe, an exercise that confirmed the validity of the tool’s sensor technology and validate once more the effectiveness of the platform to inspect pipelines.

The insertions went off without a hitch, and the PipeDiver sailed through the pipeline obstacle course with ease, gathering EM data along the route.

Results
Of the approximately 237 pipe sections inspected during the real inspection, four pipes were identified with anomalies indicative of cylinder wall loss, ranging between 30 percent and 60 percent. The wall loss defects ranged from 10.8 to 37.7 cubic centimeters (0.64 to 2.30 cubic inches).

After the inspection, three out of the four locations were dug-up to verify the reported defects, using non-destructive ultrasonic techniques. On each of the locations, the defects were found, and the actual material loss was in the range of the reported material loss.

Overall, the results proved the worth of PipeDiver as an advanced condition assessment tool able to deliver precise, actionable data on metallic pipes. The exercise showed the PipeDiver tool as a cost-effective solution versus methods that have operational constraints or require a shutdown or dewatering, or in this case, taken out of service. Evides estimated capital savings of 1.1M Euros as a result of the inspection and repairs.

Quote

“PipeDiver proved to be a suitable tool for one of our most important inspection needs: Corrosion of cement-lined steel pipes. We are especially glad the tool was able to pass a butterfly valve, and to be inserted and extracted through 600mm manholes, as this greatly improves operability and cost effectiveness.”

–Bart Bergmans, Project Manager, Infrastructure Asset Management, Evides Watercompany

Case Study

Daphne is located along the eastern shore of Mobile Bay, an area served by Daphne Utilities, which provides water, wastewater, and natural gas services to approximately 25,000 residents.

In 1985 the City purchased the Lake Forest Utility, and in doing so, Daphne Utilities took over their existing wastewater treatment plant, which was built in the 1970s.  The facility discharges through the Daphne Outfall, a 6,000-foot, 18-inch ductile iron effluent pipeline that discharges treated wastewater into Mobile Bay. Although the main was critical to the City, little information about it was transferred when Daphne Utilities acquired the facility.  Daphne Utilities later officially named the facility the Water Reclamation Facility.

Project Details

Services
Mapping deliverable

Pipeline alignment

Sahara® leak and gas pocket detection

Timing
One (1) day
Pipe Material
Ductile Iron
Inspection Length
1000 feet (304 meters)
Diameter
18-Inch (457mm)
Transmission Type
Treated Wastewater

Project Highlights

Pipeline assessment hampered by

non-existent plans

Obstacles in pipeline path include

urban development and wildlife sanctuary

Zero (0) leaks

eight (8) gas pockets detected

One (1) day

mobilization
1000ft inspected

Challenge
For many years after Daphne Utilities took over the Water Reclamation Facility the outfall line operated as a gravity discharge line. As the population grew and flows to the plant increased, Daphne Utilities installed pumps to occasionally increase the volume of treated wastewater passing through the discharge line. As development expanded, the situation progressed from a time when the pumps occasionally ran, to the point where the pumps ran almost continuously.

Gravity main transformed into a force main

Now, a pipe designed as a gravity main had transformed into a force main, pumping under pressure at all times, with its location and condition unknown – and with no redundancy.

To proactively manage this critical asset, in June 2015, Daphne Utilities retained the services of Pure Technologies (Pure) for a one-day Sahara® leak and gas pocket detection inspection of the Daphne Outfall, with a mapping deliverable.

The primary purpose of the inspection was to determine the pipeline alignment, since you can’t maintain what you can’t locate.  Since the 18-inch outfall was built, the terrain had changed markedly.  The original shoreline had been extended by hundreds of feet to accommodate the construction of a major highway and several hotels and restaurants.
In fact, based on best guesses and poor drawings, Daphne Utilities suspected that a five-story Hampton Inn had been built on top of the 18-inch outfall!
In short, Daphne Utilities didn’t know the exact pipeline location or its operational conditions.

Solution
To ascertain the alignment and condition of the 18-inch outfall, Daphne Utilities engaged Pure Technologies for a single day inspection.  In addition to the challenge of not knowing the exact pipeline alignment, it also appeared that the pipeline traversed under a swamp sanctuary for hundreds of alligators and other wildlife, in an area known as “Gator Alley.”

To conduct the mapping and assessment survey, Pure recommended the Sahara leak and gas pocket detection platform. Sahara is an inline tethered tool that can assess pipelines 6 inches and larger, without any disruption to service.

Because the sensor tool is tethered, an operator can stop and reverse the tool to investigate acoustic events such as leaks, gas pockets and visual anomalies. At the same time, an above-ground operator locates the sensor above ground, marking the exact location of the pipeline at any point along the pipe with sub-meter accuracy.

The mapping capability of Sahara allows utility owners to determine the exact location of their pipeline at any point, as well as the location of any leaks or gas pockets.

Results
Analysis of the acoustic data identified zero (0) leaks and eight (8) air pockets, which were impacting the efficiency of the line, as gas pockets occupy space within the already maxed-out pipeline. During the inspection, the alignment of the pipeline was determined and recorded from the treatment plant to the edge of the marsh where Mobile Bay starts, confirming the pipeline does indeed pass underneath the Hampton Inn.

In a single day, the Sahara crew determined flow velocity, inserted the tethered tool, inspected 1,000 feet, determined the pipeline alignment, and confirmed its location and the location of 8 gas pockets. As a result, Daphne now knows they have gas pockets and they now know the line location in order to execute a plan to deal with the gas pockets.

Not bad for a day’s work.

Case Study

Metropolitana Milanese (MM) manages the integrated water services for the City of Milan, which has more than 2,295 kilometers (1,430 miles) of pipeline in their network.  MM identified a critical transmission main as a priority for inspection, and proactively assessed a nine kilometer section using the SmartBall inline leak detection tool.  The Assiana Linate Transmission Main was selected as a high value main due to its location in the heart of Milan. A rupture would prove to be costly and disruptive to the city, and Metropolitana Milanese had no prior condition information on the main’s integrity.

Project Details

Services
SmartBall® Inline Leak Detection
Timing
2015
Pipe Material
Steel
Inspection Length
9 kilometers (5.5 miles)
Diameter
1200mm (48-inch)
Transmission Type
Water

Project Highlights

23
leaks in 9km identified by SmartBall® inspection

Inspection identified high concentration of leaks in specific zones

Program costs expected to be repaid in 3 years from water savings

Challenge

Assessing the condition of buried infrastructure can be challenging and difficult to predict. Traditional belief dictates the condition of the pipe is directly associated with its age, however extensive field work shows this is not always the case. One-hundred year old pipes can be dug up in like-new condition, and newer pipes can show extensive damage due to operational, environmental, and installation factors. While the Assiano Linate Transmission main, a 1200mm steel transmission main situated in the heart of Milan, was installed in 1982 and therefore is not particularly old, its important nature to the network made it a priority for assessment. Reducing Non-Revenue Water (NRW) is a major concern for municipalities and a proactive approach to pipeline inspection is critical to managing investments.

Solution

Metropolitana Milanese proactively assessed a nine kilometer section of the Assiano Linate Transmission main using the SmartBall leak detection tool. This technology was chosen to allow the transmission main to remain in operation during the inspection, a critical requirement due to the networks served by the main.

The tool is a free-flowing leak detection platform that operates while the pipeline remains in service. It is capable of completing long inspections in a single deployment and is equipped with an acoustic sensor that identifies acoustic anomalies associated with leaks and air pockets. The acoustic signature is then analyzed to determine if it is a leak, air pocket, or an external noise.

Identifying leaks small or large contributes to maintaining the condition of a transmission main. In metallic pipe materials, a catastrophic failure is often preceded by a period of leakage, so identifying and repairing leaks can help to reduce water main failures, as well as reduce Non-Revenue Water loss not detected in water balances.

Results

The SmartBall inspection identified 23 large leaks within 9 kilometers of pipeline inspected. One area of high leak concentration detected 8 leaks in a short 240 meter section. Although Metropolitana Milanese chose a low resolution tool for their assessment program, the concentrated location of the leaks resulted in an accurate condition assessment by finding the weak link in the transmission main.

While many leaks were detected during the inspection, because the overall flow of the main is high, the leakage was undetectable with traditional metering equipment. However, the potential savings from the leak detection program are significant enough to have a positive impact on the city’s Non-Revenue Water Program, and its finances.  Although the production cost of water is relatively low, the expected savings in water loss from repairing the leaks will pay back the costs of the project in approximately three years, including the cost of repair to the damaged section.

Furthermore, the results indicated that limited portions of the main have damage while most of the pipeline appears to be in relatively good condition. This gives a targeted area for repairs without the need to dig up large sections of the pipeline – a costly and time-consuming process.

By determining the specific locations of leaks on the Assiano Linate Transmission Main, Metropolitana Milanese will be able to reduce its NRW and has gained a better understanding of the overall condition of the pipeline. This will aid in future capital planning and will also provide a valuable study into determining the external factors that might be causing the leakage.

Focused repair works for the leaks will allow the utility to extend the life of the pipeline and reduce water loss, thus improving the overall service to its customers. The final data from the inspection will be presented in an innovative asset management overview to Metropolitana Milanese.

Quote

“SmartBall has been a cost-effective solution to assess the condition of a very critical pipe in our network without causing any negative impact in our daily operations.”

–Metropolitana Milanese

Case Study

The City of Montreal supplies drinking water and wastewater services to a population of nearly 1.9 million people. Starting in 2007, Pure Technologies (Pure) began working with the City’s potable water transmission division on a pipeline assessment program that included electromagnetic (PureEM) inspection and acoustic monitoring.

In 2015, as part of a pre-emptive program to reduce loss of non-revenue water and understand the condition of their pipes, the City partnered with Pure to conduct an ongoing, three-year leak detection survey on a series of critical pipes within its potable water network located mostly in the downtown core.

Project Details

Services
Sahara® leak detection

CCTV visual inspection

Timing
2015-Ongoing
Pipe Material
BWP, Steel, Cast Iron, PCCP
Inspection Length
28.9 km (18.5 m)
Diameter
500mm – 1200mm (20-inch – 48-inch)
Transmission Type
Water

Project Highlights

20.8 miles (33.5 kms) inspected to date

46 insertions completed

24 leaks identified

9 leaks identified as feature leaks

Challenge
The City recognized the value of detecting leaks, however small, to prevent these from developing into greater problems. While leaks occur most frequently on small-diameter distributions mains, leaks and ruptures on trunk mains are a much bigger concern for utility operators due to the relatively higher consequence of failure.

In addition to physical losses of water caused by a series of small leaks, the escaping water can eventually erode the surrounding soil making the area more prone to washouts or sinkholes, a major headache especially in densely populated areas. Leaking water can eventually find its way to the surface, or into sewers, overburdening the system. Unplanned excavations to repair unforeseen leaks can also erode consumer confidence in a public utility.

Solution
For its multi-year leak detection program, the City requested Pure to deploy its highly reliable and precise Sahara® acoustic video inspection on 46 kilometers of pipelines chiefly in the downtown core. The pipeline sections consist of PCCP, BWP, cast iron and steel.

The Sahara platform comes with a variety of sensor tools to perform the inspection. This includes an acoustic sensor to perform leak and gas pocket detection, and high-resolution video camera to assess internal pipe conditions.

Because the Sahara tool is drawn by product flow via a small drag chute, and is tethered to a data acquisition unit on the surface, it gives the operator close control to confirm suspected leaks, gas pockets and other visual anomalies. The tool can visually confirm pipe irregularities, continuously recording, allowing for both real-time and post-processing analysis.

For the Montreal project, the purpose of the Sahara inspection was to assess the condition of the pipeline by identifying and locating leaks, pockets of trapped gas and to identify larger visual anomalies utilizing Closed Circuit Television (CCTV) footage collected during the inspection. The data would help shape the rehabilitation urgency and timing.

 

Results
To date, Sahara has had 46 insertions and a total of 33.5 kilometers (20.8 m) have been assessed. Analysis of the data identified 24 leaks and zero (0) gas pockets in the pipeline sections inspected. The Sahara sensor was tracked above ground using the Sahara Locator® device to track the Sahara tool and locate any potential leaks or anomalies found.

 The assessment is proving its worth from a verification viewpoint, and the leaks have been either repaired or addressed for prioritization. The current program is scheduled for completion by 2017.

With its pre-emptive leak detection program, the City is Montreal is a great example of a smart water manager taking proactive efforts at keeping its network in healthy shape.

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Case Study

In 2015, Utilities Kingston retained the services of Pure Technologies to perform a condition assessment on the Dalton Avenue (North End) Pump Station Force Mains.

At approximately 35 years, each asset was entering a critical stage of its life-cycle. The purpose of the assessment was to identify the structural condition of the 450mm and 600mm force mains, both of which are approximately 1,550 meters long and follow a parallel route.

The assessment included transient pressure monitoring, a SmartBall® leak and gas pocket detection survey, and a PipeDiver® electromagnetic inspection of the pipeline.

Project Details

Services
SmartBall® leak and gas pocket detection
PipeDiver® electromagnetic inspection
Transient pressure monitoring
Risk of failure evaluation
Timing
2015
Pipe Material
Ductile Iron, Steel, Reinforced Concrete
Inspection Length
3.05 kilometers (1.9 miles)
Diameter
450mm to 600mm (18 inch to 24 inch)
Transmission Type
Wastewater

Project Highlights

 

3.05 kms cumulative distance of survey

 

1 acoustic anomaly associated with transient gas (SmartBall inspection)

55 pipes with EM anomalies characteristic of localized wall loss (PipeDiver inspection)

 

Zero leaks detected

 

Challenge

The older of the two force mains is 450mm (18-inch) in diameter, constructed of ductile iron built in the late 1950s, and had failed several times over its lifetime. The newer of the two force mains is 600mm (24-inch) in diameter, built from reinforced concrete (RCP) and steel, with two sections of suspected metallic pipe, which was not confirmed in the profile drawings.

As the pipe material specifics were still unknown at the time of the inspection, Pure Technologies elected to conduct a PipeDiver run to accommodate both possible types of pipe material – assumed by all to be bar wrapped pipe (BWP) and prestressed concrete cylinder pipe (PCCP).

Historically, it has proven challenging to assess the condition of pressurized mains that carry sewage, especially those made with ferrous material. Metallic force mains have special operational challenges that don’t apply to gravity sewer systems, and due to the presence of solids in the flow, force mains represent a far more abrasive environment than potable water systems.

Gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall. This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Solution

Transient pressure monitors were installed on the header of each force main and for nearly five weeks the recorded pressure data was used to understand the operational and surge pressures within the force mains and their impact on the structural integrity of the pipelines.

Utilities Kingston began the initial force main condition assessment by deploying SmartBall technology, a free-flowing multi-sensor tool used to detect and locate the acoustic sounds related to leaks and gas pockets in pressurized pipelines. The tool has the ability to inspect long distances in one run, and requires only two access points, one for insertion and one for extraction. SmartBall is an effective condition assessment tool for force mains, which don’t typically feature butterfly valves, allowing the SmartBall to roll through the line quite easily, collecting acoustical data.

Following the SmartBall run, UK deployed the free-swimming PipeDiver assessment tool, which travels with the product flow, and utilizes flexible petals to navigate butterfly valves, tees and bends in the pipeline. Originally designed for use in pressurized concrete cylinder pipes (PCCP), the tool has specialized electromagnetic sensors (PureEM) to identify and locate broken prestressing wire wraps, (one of the main structural components and failure modes of a prestressed concrete pipe).

Historically, technologies available to assess the condition of metallic pipe have been limited. This led Pure TEchnologies to develop the specialized PipeDiver for metallic pipes, equipped with advanced electromagnetic technology to identify broken bars in bar wrapped pipe, and localized areas of wall loss in BWP, steel and ductile iron.

Results

In the end, one (1) acoustic anomaly characteristic of transient gas on the 450mm force main was identified with data collected during the SmartBall inspection. No acoustic anomalies were identified within the 600mm force main during the SmartBall inspection.

Of the 650 pipes inspected with the PipeDiver tool, a total of 55 pipes in the 450mm Dalton Avenue Pump Station force main had electromagnetic anomalies characteristic of localized wall loss. These results represent a high percentage of distress along the length of the pipeline and indicate a high risk of failure.

Recommendations included an extended period of transient pressure monitoring as the maximum pressures recorded exceed the 600mm RCP design limitations. Utilities Kingston should also review the pressure reducing valves at the pump station and investigate the operating procedures to determine the cause of the transient pressures.

The fact-finding data collected from both the inspections and transient pressure monitoring gave Utilities Kingston a better understanding of their real, not assumed assets. The results, which included a DIP risk of failure analysis, were used to complete a structural evaluation of the force mains, and have provided Utilities Kingston with actionable information regarding any necessary repairs or rehabilitation.

Lyon City Square

With a population of nearly 500,000, Lyon is the third largest city in France, a vibrant metropolis known for its modern Confluence district as well as Renaissance palaces and Roman ruins that date back more than 2,000 years.

While Lyon’s historic architecture has aged well, the same cannot be said for its buried infrastructure. In June of 2016, Suez retained the services of Pure Technologies (Pure) to perform a SmartBall® inspection of two critical water mains, the Grigny Water Main and Les Halles Water Main, both located near Lyon. The inspections, conducted over two days, were part of a long-term condition assessment program for the city.

As an industrial services and solutions company specialising in securing and recovering resources, Suez provides its customers (local authorities, industry and consumers) with concrete solutions to address new resource management challenges.

Pipelines constructed of ductile iron and cast iron

The Grigny Water Main is a 500mm (20-inch) cast iron pipeline that transfers Water from the Grigny Pump Station to Saint Romain en Gier. The SmartBall inspection started at a previously installed 150mm (6-inch) tap and ended at a previously installed 150mm tap in Saint Romain en Gier, and covered a distance of approximately 8.6 kilometers (5.3 miles).

The following day Pure deployed a second SmartBall inspection, this time on the Les Halles Water Main, a 400mm (16-inch) ductile iron pipeline that transfers water from Les Halles to Saint Laurent D Chamousset. The purpose of the inspection was to locate and identify leaks and pockets of trapped gas along the 2.9 kilometer (1.8 mile) section of pipeline.

SmartBall under a gas pocket inside a water pipe

SmartBall® tool chosen for ease of use and sensitivity to gas pockets and small leaks

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and its ability to inspect long distances in a single deployment. The free-swimming, acoustic-based SmartBall tool is inserted into the pipeline flow, and after traversing the inspection length, the tool is captured and extracted at a point downstream.

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

For this project, 13 surface-mounted acoustic sensors (SMS) were placed along the Grigny pipeline to track the SmartBall tool during the inspection. For the Les Halles inspection, five (5) SMS were used to track the tool. SmartBall receivers were connected to the sensors on the pipeline at locations to track the tool during inspection.

An extraction net was used to extract the SmartBall tool once it traversed the entire length of both pipelines, and the data was evaluated by Pure analysts to identify acoustic anomalies associated with leaks and pockets of trapped gas.

Screen with Data Analysis

SmartBall survey detects two leaks and zero (0) gas pockets

The acoustic data recorded by the SmartBall tool was analyzed and cross-referenced with the position data from each SmartBall Receiver (SBR) to determine a location for each acoustic anomaly.

From the results conducted on the Grigny Water Main, Pure detected a total of two (2) acoustic anomalies characteristic of leaks and zero (0) anomalies consistent with pockets of trapped gas. Pure analysts classified one leak as a small leak, and a second as a large leak.

For the survey of the Les Halles Water Main, Pure detected zero (0) anomalies characteristic of leaks and zero (0) acoustic anomalies characteristic of pockets of trapped gas.

The results gave Suez actionable data regarding the condition of the pipelines, and the confidence to move forward on fixing the leaks. It’s a great example of a water authority taking proactive efforts at keeping its network in healthy shape.

SmartBall with case and insertion tools

What keeps a water utility manager up at night? Getting a phone call from a distraught resident about an unplanned (and unwanted!) ornamental pond developing in the cul-de-sac.

On an already soggy, wet day in early November 2016, water began filling a cul-de-sac in an affluent neighbourhood in the City of Southlake, Texas. To contain surface flooding, Southlake water authorities took immediate remedial action by sequentially shutting down each water line in the area in an attempt to isolate the leak.

“As for using the Sahara tool to find the leak, upon saw cutting the street and excavating, Pure Technologies hit the bullseye yet again for Southlake.” Kyle Flanagan

Water Department Supervisor, City of Southlake

In addition, the City used external listening devices to try and locate the leak – the external listening devices indicated that some kind of leak was present, but the City was unable to pinpoint the location. In the end, the City had to shut down the 42-inch Caylor bar-wrapped potable water main, a low-pressure gravity main passing through the area. This was done to confirm that the 42-inch Caylor Main was leaking.

Sure enough, once the 42-inch Caylor Main was shut down, the water stopped surfacing. When the City reopened the main, the water did not resume surfacing. Despite the inconclusive evidence, the City remained convinced that the 42-inch main was the leak source.

Workers with horses in a field

Soggy ground, horse pasture and and muddy conditions hamper inspection

With uncertainty remaining, the City of Southlake called in Pure Technologies to assist in identifying and locating the leak. Unfortunately, the bad luck continued, as heavy rains and muddy conditions hampered Pure and its mobilization truck from access to the pipeline right-of-way. Even crews from Southlake got stuck when they tried drive the pipeline right-of-way.

One possible additional access point was available through a private owner’s horse pasture, but low-hanging power lines created a safety hazard that would prevent crews from accessing the site by that route.

Disappointed, the crews demobilized to wait for better weather or a better access point.

Sahara device

Sahara® platform selected for speed, accuracy and on-the-spot results

The next day Southlake identified another access point 1,000 feet further upstream, and prepared it for the Sahara inspection.

The Sahara leak detection platform was selected for its ability to provide same day results, and to accurately locate small leaks with sub-meter accuracy. The tethered tool is propelled by a small parachute inflated by the product flow, requiring a flow velocity as little as one foot per second to progress through a water main.

Because the Sahara inline tool is tethered, an operator has complete control, and can closely examine events of interest such as leaks, gas pockets and visual anomalies in real time.

The tool can detect up to four times as many leaks as correlators because the acoustic sensor is brought right to the leak. The Sahara platform also features inline video that allows operators to observe internal pipe conditions, and many times identify the type of leak – indicating if the leak is on a joint, in the pipe barrel, at a feature, and other details helpful for planning a repair before excavating.

Pipe inner surface

Second attempt to find the leak

For the assembled crews, pressure escalated to quickly find the leak location.

Once the Pure mobilization crew set up the installation equipment and inserted the Sahara sensor, the pressure gauge indicated only 36 PSI, not the best scenario for leak detection. Furthermore, the inspection was heading uphill toward the area of interest, and could expect even lower pressure nearer to the suspected leak location area due to loss of head pressure as the pipe ascended the slope.

Further complicating matters, the pipe wall thickness was determined to be about 4 inches, and leak paths that pass through 4 inches of concrete and mortar can often include sharp bends that can muffle leak signatures.

From the insertion point, Sahara inspected a total of 2,400 feet, passing through the cul-de-sac area at around 1,600 feet from insertion.

Sahara platform inside a pipe filled with water

A slow pullback of the tethered Sahara tool to recheck areas of interest

During deployment, review of acoustic data noted a few areas of interest, but nothing definitive. The inspection continued past these areas of interest in the hopes of finding something more conclusive.  When nothing was found, the Pure crew began a slow pullback of the tethered Sahara tool to recheck the areas of interest.

One of the benefits of a tethered tool is that two inspection passes can be conducted on the same section on the same day.

Of the possible leak areas, one acoustic anomaly seemed promising, and that spot was marked above ground.

Since Pure could not get a consistent peak location, and since the audio lacked many classic leak characteristics, it was flagged as an anomaly on site. After review of the acoustic signature off site using advanced sound enhancing software, Pure Technologies was able to resolve the signature as a leak, and reported it as a leak to the City of Southlake.

Because this suspected leak did not, even in post analysis, present with all the elements of a leak signature, and because it lacked a distinctive peak location, Pure Technologies recommended that the City of Southlake check a 7-foot length of the pipe, all the way around the pipe.

Worker digging to reveal the leak

Surprise, surprise, 4 leaks verified

As directed, Southlake crews excavated the indicated areas and found not one but four leaks. The presence of four leaks in close proximity to one another, all at low pressure, explained the difficulty of finding a leak peak.

The four leaks located ranged from pencil-sized to quarter-sized. The sloppy mortar job over an access plate into the 42-inch Caylor Main was just good enough to help muffle the leaks, but not good enough to protect the cylinder from corrosion and eventual leakage.

Small leak before being fixed

In the end, despite difficulties of inspecting small leaks in a low-pressure environment, the inspection was deemed a success, and Southlake was extremely pleased with the accurate results.

Thanks to collaboration between crews from Southlake and Pure, the mystery leak was solved. The inline tethered Sahara tool came through again.

Calgary, Alberta and Rye Brook, N.Y., April 25, 2017 – Pure Technologies Ltd. (TSX: PUR) and Xylem (NYSE: XYL) announced today that they have entered into a commercial collaboration whereby Xylem will represent Pure’s products and services to the water sector in the Gulf Cooperation Council countries (UAE, KSA, Qatar, Bahrain, Kuwait and Oman), and in India, Singapore and Malaysia.

Pure provides a wide range of patented technologies for managing critical infrastructure across the water, wastewater and key transportation sectors. Xylem is a global water technology leader that offers solutions for managing water across the water cycle. Both companies are actively engaged in addressing customer challenges in water infrastructure, including non-revenue water, extending asset life, and reducing the risk of water main breaks.

Water faucets leaking

“We are delighted to partner with Xylem in promoting our shared vision of applying innovative technologies and strategies to reduce water loss and for pro-active management of water and wastewater pipeline infrastructure,” said Jack Elliott, President and CEO of Pure Technologies Ltd. “Pure has been active in these countries for several years and has established a reputation for technical excellence, value and integrity.  Xylem’s strong presence in these countries will help to grow the market for Pure’s solutions.”

“We are excited to be working with Pure in this new collaboration, which will help us reach even more customers with critical solutions,” said Patrick Decker, President and CEO of Xylem. “It is a natural extension of Xylem’s strategic focus on driving growth in the emerging markets and offering smart water technologies to better meet our customers’ immediate and emerging needs.  This collaboration expands our growing partner ecosystem and helps us create value for our customers and other stakeholders by leveraging our global distribution network.”

Pure and Xylem will be hosting joint workshops in the regions over the next few months to introduce the collaboration to water agencies, industrial water users and regulators.

About Xylem

Xylem (NYSE: XYL) is a leading global water technology company committed to developing innovative technology solutions to the world’s water challenges. The Company’s products and services move, treat, analyze, monitor and return water to the environment in public utility, industrial, residential and commercial building services, and agricultural settings. With its October 2016 acquisition of Sensus, Xylem added smart metering, network technologies and advanced data analytics for water, gas and electric utilities to its portfolio of solutions. The combined Company’s nearly 16,000 employees bring broad applications expertise with a strong focus on identifying comprehensive, sustainable solutions. Headquartered in Rye Brook, New York with 2016 revenue of $3.8 billion, Xylem does business in more than 150 countries through a number of market-leading product brands.

About Pure Technologies Ltd.

Pure Technologies Ltd. is an international asset management, technology and services company which has developed patented technologies for inspection, monitoring and management of critical infrastructure around the world.

Worker joining two pieces of pipe

Using risk-based data analysis and innovative renewal strategies, two US water systems show how utilities can avoid full pipeline replacement, reduce service interruptions, and save money.

As this informative Opflow article discusses, by more precisely understanding the condition of buried infrastructure, water utilities can more effectively focus resources to prolong safety and increase reliability.

Authors: Randy Moore, Travis Wagner, Nathan Faber, Robert Stanley, Buzz Pishkur, Jessie Allen

Gateway of The North City of North Bay

On one hand, it may seem like a waste of capital dollars if you perform a pipeline condition assessment and the final analysis turns up no leaks. Alternatively, you can also look at the no-leak report as a good news validation story, especially when using the information to help establish an asset management plan.

Such was the case for a city of 51,000 situated between the shores of lovely Lake Nipissing and Trout Lake in Northern Ontario.

In September 2016, the  City of North Bay (City) retained the services of Pure Technologies (Pure) to perform a two-phase condition assessment on the Marshall Avenue Force Main (MAFM). The MAFM is a critical 508mm (20-inch) asbestos cement pipeline that services approximately half the city, and transfers wastewater from the Marshal Avenue Pump Station to the North Bay Sewage Treatment Plant.

Aerial picture with sewer map

The City was interested in exploring technologies to help them better understand the actual condition of their force main in order to implement a comprehensive asset management program using the inspection data.

To assist in the assessment, Pure Technologies elected to first conduct transient pressure monitoring, followed by a SmartBall® inspection to acoustically identify and locate leaks and pockets of trapped gas along the pipeline.

Transient pressure monitoring helps understand structural integrity of the pipeline

First, transient pressure monitors were installed at the pump station discharge header. For approximately six weeks, the recorded pressure data was used to understand the operational and surge pressures within the force main and their impact on the structural integrity of the pipeline.

When pipe wall degradation is combined with surge pressures, the likelihood of pipe failure can be significantly increased.  Evaluation of the pump station operation, such as pump start-up mode, typical and peak flows, operating and surge pressures, and surge protection, can provide important information on the stress.

SmartBall with its controls and tools

SmartBall tool provides acoustic signature related leaks and gas pockets

While transient pressure data was collecting, Pure deployed its proprietary SmartBall technology, a multi-sensor tool used to detect and locate the acoustic signature related to leaks and gas pockets in pressurized pipelines. The tool has the ability to inspect long distances in a single run, and while the SmartBall is deployed, the pipeline remains in service, limiting disruption to customers.

Unlike traditional listening tools like correlators, which have limited success on large diameter pipes, the free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls inside the pipe, it can inspect every inch of the main to detect leaks and gas pockets.

From insertion to extraction, the SmartBall inspection took a little over four hours, with no unexpected events as anticipated during the planning stage.

SmartBall functionality chart

Results lead to effective management of finances and risk

Based on the inspection data, Pure analysts reported zero (0) anomalies characteristic of leaks, and 13 acoustic anomalies characteristic of pockets of trapped gas, mostly around air valves.  In particular, gas pockets are of significant concern in force mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall. This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Gas pockets combined with pressure transients can have significant impact on the pipeline, as vacuum conditions may be created. This can cause cavitation at the gas pocket as the transient gas passes, increasing stress on the pipe wall and therefore increasing the risk of failure if the structural capacity has been compromised.

City considering adding more air valves to help expel collecting gas

Based on a hydraulic evaluation of the pipeline, structural fatigue was not a concern, although test pits were recommended to determine asbestos cement thickness and gas pocket mitigation using swabs also recommended. In the near term, the City is considering adding more air valves to the pipeline to help expel collecting gas.

Overall, the City of North Bay was pleased with the project results, as they were able to understand the overall condition of the pipeline and make an informed decision for capital improvements of the Marshall Avenue Force Main. The project demonstrates how the City uses actionable data to effectively manage their finances and risk, while continuing to provide the community with a safe and reliable delivery of wastewater.

Massive pressured water leak

According to AWWA’s 2016 Benchmarking Survey, the average water and wastewater utility has seven breaks per 100 miles of piping every year. Tip-top systems experience just four breaks in that distance, while those at the bottom have 18.

While it’s interesting to note the difference in break rates, it’s unfair to compare one utility to another, as a multitude of factors come into play as to why pipelines can deteriorate to state of failure. Countless sources of stress both inside and outside a pipe related to geographical location, soil-pipe type interactions, age, and construction are among factors that can take their toll on the pipe’s condition.

Worker inspecting pipe

For utilities, the one constant across the spectrum is the acknowledgment that simply replacing pipeline assets is cost prohibitive, and that advanced condition assessment services like those provided by Pure Technologies (Pure) can help utilities confidently make informed decisions that significantly reduce capital and operating costs.

Single-episode blowouts garner all the attention

While single-episode blowouts are quite rare, these tend to garner most media attention, and cause the most obvious blowbacks to the pipeline operator. What the public doesn’t usually notice are the pinhole leaks, hairline cracks, corrosion and leaking gaskets that tend to occur first.

Most catastrophic failures are caused by a sudden unexpected stress such as a water hammer acting on an existing weak point in the pipe. There is a widely held belief that the failure process is a simple one, where a pipe corrodes to the point at which it can no longer withstand the applied internal and external forces, resulting in a main break. However, research has shown that the failure process is more complex than expected.

Corrosion plays a significant role in water main failures, but soil-pipe interactions, manufacturing techniques and human error are also important factors. Failures also take place in multiple stages rather than in a single episode. Early damage not only weakens portions of the pipe, it also allows water to escape, causing corrosion and washing out of the supporting soil.

Broken water pipe on a street

Age alone does not indicate high-risk pipes

Pipes at highest risk are typically constructed using dated materials or methods, running through an area with heavy vehicle traffic. Urban centers typically represent significant loss potential from damage caused by water main breaks as a result of high-density buildings, underground infrastructure, important traffic thoroughfares, and economic loss potential of power, gas, water utilities and legal cases.

The net result is that age alone cannot be relied on as an indicator of a high-risk pipe.

Broken pipe

Types of pipe material and typical cause of failure

Prestressed concrete cylinder pipe (PCCP) has a unique failure mechanism: high strength steel pre-stressing wires that provide strength to the pipe can become distressed and reduce the structural integrity of the pipe. Broken wires can be caused by physical damage to the pipe, corrosion, or hydrogen embrittlement.

Areas of broken wires may be accompanied by leaks, especially in pipelines smaller than 48 inches in diameter, where the internal steel cylinder corrodes at the same rate as the wires or where water escaping through the joint encourages corrosion. Leakage has been proven to be a key indicator of structural condition in lined cylinder pipe, a type of PCCP in which the prestressing wires are placed directly on the steel cylinder. These types of leaks can create voids around the pipe and introduce added stress at an existing weak point.

Cast iron pipes corrode, become brittle and are prone to cracking. Many older North American cities have cast iron pipes that were installed in the 1800s, prior to the existence of pipeline standards, when methods of construction were non-uniform and advanced quality control programs did not exist. Consequently, many pipelines were installed using what are considered poor construction practices by today’s standards.

Ductile iron pipes have failure mechanisms similar to those of cast iron pipes; however they become less brittle and consequently degrade at a slower rate. These pipes may be capable of supporting large leaks for longer periods of time without failing immediately.

Plastic and polyvinyl chloride (PVC) pipes are less prone to corrosion and less brittle than iron pipes. Failures in these pipes are often traced to leaking joints where the escaping water creates voids around the pipeline, causing unplanned stresses on the pipe.

Steel pipes primarily fail due to loss of integrity at welds, and external corrosion causing severe pitting and weakening the pipe wall. Both losses of joint integrity and through-wall corrosion pits lead to leakage long before failure. Older steel pipes in aggressive environments are capable of sustaining massive levels of leakage for decades before failing.

Workers digging with mechanical shovel

Making ongoing condition assessment part of proactive asset management

While pipe material and typical pipe stresses are factors that can contribute to a state of pipe failure, it remains impossible to compare one pipeline to another, and to make generalized statements about remaining service life, especially based on age and depreciation. Instead, it pays to conduct ongoing condition assessment, and then to use that risk-driven asset data collection to reduce the likelihood of replacing pipe that can safely and effectively serve communities for several more years.

Mackay City Coast

Justification of an ongoing condition assessment program can, at times, be difficult for water utilities. However, successful inspections that deliver actionable outcomes on how to manage aging assets make this justification much easier.

Certainly that was the case for Mackay Regional Council (MRC) when it engaged the services of Pure Technologies to conduct a variety of condition assessment inspections on their critical mains in order to improve their understanding of these aging assets.

For MRC, the goal of the 3-year Condition Assessment Program is to undertake and then analyze the results from the preliminary inspections, followed by a commitment to explore secondary condition assessments, where warranted.

Mackay satellital image with mains map

About Mackay Regional Council

Mackay Regional Council is a small but progressive water utility that serves a population of nearly 124,000 on the eastern coast of North Queensland, Australia. The utility has a total of 2,150 km of water and wastewater mains in its network. MRC is proactive in its approach to water management, and takes pride in the development of its industry-leading condition assessment program, initiating the first leg of the program with Pure mid-2016.

SmartBall with case and insertion tools

First SmartBall inspection on two sewer rising mains

In June 2016, MRC retained the services of Pure to perform a SmartBall® inspection of the Coles Road Sewer Rising Main (SRM), also known as force main. The Coles Road SRM is an asbestos cement (AC) and ductile iron (DI) pipeline that transfers wastewater from the Coles Road Sewer Pump Station (SPS) to the Mount Basset Sewer Rising Main. The purpose of the SmartBall inspection was to identify leaks and pockets of trapped gas along the pipeline.

Pure recommended the SmartBall tool for its relative ease of insertion and extraction of in-service pipelines, and its ability to inspect long distances in a single deployment. The tool’s acoustic sensor can detect ‘pinhole’ sized leaks and gas pockets within a location accuracy of plus or minus 1.8 m (6 feet), a critical factor in urban environments where excavations can be costly and disruptive to the public.

After the review of data integrity and backup from the Coles Road site, the crew moved to the Beaconsfield SRM, where a further SmartBall inspection was completed. The inspection went as smoothly as the first, and all data was confirmed for quality.

This technology has assisted us in assessing the operational and potential structural integrity of some hard to access buried mains of high failure consequence without significant service outage or worker safety in a way not previously utilised.  It certainly lifts us out of the purely reactive mode toward the proactive assessment of buried infrastructure in terms of service delivery risk management and maintenance/renewal planning…”

MRC Project Leader

Second SmartBall inspection on a sewer rising main and raw water main

During the next phase of the project, Pure conducted a preliminary condition assessment of two more critical mains, the Mount Basset SRM and the following day, on Marwood Bore Raw Water Main. Pure always utilizes separate inspection sets for potable and wastewater to eliminate any risk of contamination.

SmartBall extraction

Second SmartBall inspection on a sewer rising main and raw water main

Results of the preliminary condition assessment were utilised to identify whether a secondary condition assessment is required.

Historically, it has proven challenging to assess the condition of pressurized mains that carry sewage, especially those made with ferrous material. Sewer rising mains have special operational challenges that don’t apply to gravity sewer systems, and due to the presence of solids in the flow, sewer rising mains represent a far more abrasive environment than potable water systems.

Gas pockets are of significant concern in rising sewer mains, as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Utilizing Sahara™ platform with CCTV

For the third phase of the Program, MRC engaged Pure for a condition assessment of the Gordon Street Water Main. In order to inspect this critical main, Pure conducted three (3) separate insertions using the Sahara inspection platform. The Sahara system uses an innovative tethered platform to conduct non-destructive inline leak and gas pocket detection, and an internal visual inspection via closed circuit television (CCTV), without disruption to service. This allows for real-time reporting of acoustic anomalies detected in the pressurized lines.

The inspection occurred over a period of two nights to minimize traffic disruption. The targeted portion of the main consists of cast iron (CI) and asbestos cement (AC) pipe in three diameters.

“We are still to progress fully into this mode of operation, however this technology appears to provide us a firm foundation to step off from…”

Don Pidsley

Working during the night

Collected data gives MRC actionable information on necessity for secondary assessments

All in all, the data collected to date has given MRC a better understanding of their critical assets. By undertaking a preliminary condition assessment approach, MRC now has actionable information regarding the necessity of future secondary assessments.

Based on preliminary results, minimal disruption and collaborative cooperation between the mobilization teams, MRC has inquired about additional inspections under their in their industry-leading condition assessment program.

Workers meeting in a parking

Some pipeline inspections are more daunting than others, as Daphne Utilities recently found out. Not only was the planned condition assessment on a critical pipeline hampered by non-existent plans, there were also obstacles in the pipeline path that included urban development atop the pipe and an alligator-infested swamp.

In the end, to map and assess their pipeline, Daphne Utilities opted for the Sahara® leak and gas pocket detection platform, which includes the ability to determine pipeline alignment with sub-meter accuracy.  With the Sahara platform, Daphne Utilities could not only determine the exact pipeline location, but also assess its operation and condition.

Daphne’s Story

Affectionately known as the “Jubilee City”, Daphne was incorporated in 1953 and due to its location, serves as a suburb of Mobile, Alabama. Daphne is located along the eastern shore of Mobile Bay, an area served by Daphne Utilities, which provides water, wastewater, and natural gas services to approximately 25,000 residents.

In 1985 the City purchased the Lake Forest Utility, and in doing so, Daphne Utilities took over their existing wastewater treatment plant, which was built in the 1970s.  The facility discharges through the Daphne Outfall, a 6,000-foot, 18-inch ductile iron effluent pipeline that discharges treated wastewater into Mobile Bay. Although the main was critical to the City, little information about it was transferred when Daphne Utilities acquired the facility.  Daphne Utilities later officially named the facility the Water Reclamation Facility.

For many years after Daphne Utilities took over the Water Reclamation Facility the outfall line operated as a gravity discharge line. As the population grew and flows to the plant increased, Daphne Utilities installed pumps to occasionally increase the volume of treated wastewater passing through the discharge line. As development expanded, the situation progressed from a time when the pumps occasionally ran, to the point where the pumps ran almost continuously.

Satellite view with sewer location

Over the years the gravity main transformed into a force main

Now, a pipe designed as a gravity main had transformed into a force main, pumping under pressure at all times, with its location and condition unknown – and with no redundancy.

To proactively manage this critical asset, Daphne Utilities retained the services of Pure Technologies for a one-day Sahara® leak and gas pocket detection inspection of the Daphne Outfall, with a mapping deliverable.

The primary purpose of the inspection was to determine the pipeline alignment, since you can’t maintain what you can’t locate.  Since the 18-inch outfall was built, the terrain had changed markedly.  The original shoreline had been extended by hundreds of feet to accommodate the construction of a major highway and several hotels and restaurants.

In fact, based on best guesses and poor drawings, Daphne Utilities suspected that a five-story Hampton Inn had been built on top of the 18-inch outfall!

In short, Daphne Utilities didn’t know the exact pipeline location or its operational conditions.

Bridges over a river

Section of the outfall traverses area known as “Gator Alley”

To ascertain the alignment and condition of the 18-inch outfall, Daphne Utilities engaged Pure Technologies for a single day inspection. In addition to the challenge of not knowing the exact pipeline alignment, it also appeared that the pipeline traversed under a swamp sanctuary for hundreds of alligators and other wildlife, in an area known as “Gator Alley.”

Due to the location that the line traverses, extra safety precautions were needed for the inspection crews. Project planning included the deployment of an alligator watchman to watch specifically for a notorious 14-foot alligator known to inhabit the area in the vicinity of the 18-inch outfall.

Sahara inspection technology chosen for accuracy at pinpointing leaks and gas pockets

To conduct the mapping and assessment survey, Pure recommended the Sahara leak and gas pocket detection platform. Sahara is an inline tethered tool that can assess pipelines 6 inches and larger, without any disruption to service.

Because the sensor tool is tethered, an operator can stop and reverse the tool to investigate acoustic events such as leaks, gas pockets and visual anomalies. At the same time, an above-ground operator locates the sensor above ground, marking the exact location of the pipeline at any point along the pipe with sub-meter accuracy.

The mapping capability of Sahara allows utility owners to determine the exact location of their pipeline at any point, as well as the location of any leaks or gas pockets.

Results give Daphne jubilant confidence moving forward

Analysis of the acoustic data identified zero (0) leaks and eight (8) air pockets, which were impacting the efficiency of the line, as gas pockets occupy space within the already maxed-out pipeline. During the inspection, the alignment of the pipeline was determined and recorded from the treatment plant to the edge of the marsh where Mobile Bay starts, confirming the pipeline does indeed pass underneath the Hampton Inn.

Not bad for a day’s work

In a single day, the Sahara crew determined flow velocity, inserted the tethered tool, inspected 1,000 feet, determined the pipeline alignment, and confirmed its location and the location of 8 gas pockets.  As a result, Daphne now knows they have gas pockets and they now know the line location in order to execute a plan to deal with the gas pockets.

As for dealing with alligators, that’s unnecessary now.

Alligator watching to the cammera
Staff members behind an open pipe

When you’re a regional water authority with a sound way to identify problems with your aging water pipeline before the problems get bigger, it’s cause for a celebration, highlighted with speeches, live demonstrations and cake included in the ceremony.

In late November 2016, a delegation of government officials, special guests and educators gathered in London, Ontario Canada  to celebrate the successful funding, installation and commissioning of a 60 km (37 miles) Acoustic Fiber Optic (AFO) system installed on the Lake Huron Water System’s water transmission pipeline.

Map with pipeline location

Pipeline draws water from near Grand Bend to terminal reservoir north of London

The pipeline, which supplies drinking water to more than 500,000 people in southwestern Ontario, draws water from the Lake Huron water treatment plant near Grand Bend to the terminal reservoir just north of London. Constructed of 1200mm (48-inch) prestressed concrete cylinder pipe (PCCP), the Lake Huron-to-London pipeline has ruptured four times, most recently in 2012.

To mitigate the chance of a future catastrophic failure on such a critical line, the water authority for the Lake Huron Primary Water Supply System collaborated with Pure Technologies (Pure) to install an acoustic-based monitoring system, designed to ensure the success of the Region’s long-term comprehensive pipeline management program.

The $7.5 million upgrade to the Lake Huron-to London water line is part of $179.1 million in water safety infrastructure investments across Southwestern Ontario.

SoundPrint® AFO Fiber Optic wire

SoundPrint Acoustic Fiber Optic technology tracks and records pipeline deterioration

Pure’s SoundPrint Acoustic Fiber Optic (AFO) monitoring technology is an industry-leading system that that listens, identifies and locates pipeline deterioration in real time. Once installed on a pipeline, the SoundPrint AFO system remotely detects the acoustic signature of wire breaks or “pings” in prestressed concrete cylinder pipe, and records their specific pipe location. If break activity increases, utility staff are alerted and can intervene on the deteriorating pipe in advance of failure.

Under the new system, “We will get an email to say a section of pipe has a break, and they even give us the map location of where it happens,”

John Walker

Operations Manager, Lake Huron and Elgin Area Primary Water Supply

The AFO system remotely detects the acoustic signature of breaks in the pipeline structural reinforcement and records the specific pipe location of the deterioration, alerting operating staff who can intervene in advance of a catastrophic failure of this regionally significant water transmission pipeline.

“A snapping wire or two won’t sound an alarm bell,” says Heather Edwards, project manager at Pure. “But when our monitoring team listens and identifies a large number of pings from wires breaking in a concentrated location, that’s when we focus attention on the acoustic anomalies to determine whether remedial action needs to take place.”

By managing their pipelines with innovative technologies, utilities can save millions of dollars

The project was special for Pure as it showcased the innovative SountPrint AFO technology upon which the company was founded more than 20 years ago.

“We love partnering with forward-thinking utilities like London Region to save money by using innovative technologies like the AFO system,” said Mike Wrigglesworth, senior vice-president of Pure Technologies, who spoke at the ceremony. “Instead of budgeting for an expensive replacement program or dealing with disruptive bursts, London Region has saved millions of dollars by actually managing their pipeline.”

Pure surpasses 700 miles (1,100 km) AFO monitoring milestone

Globally, Pure has surpassed 700 miles (1,100 km) of active AFO monitoring. Currently within North America and China, Pure monitors 56 mains from a combined total of 17 clients, including London Region. Pure’s active AFO system has recorded more than 43,600 wire breaks from its managed roster of pipelines located in North America and China alone.

With the installation of AFO technology in place, the London Region utility ensures active management of their most valuable buried assets, for the life of the asset.

That’s a comforting thought, well worth celebrating.

Sahara platform inside a pipe filled with water

For more than 15 years, water operators have relied on the Sahara® leak detection platform for speed, accuracy and on-the-spot results required for inspection of complex pipeline networks typically found in urban environments.

The Sahara in-line tethered tool can assess pipelines 6 inches and larger, while the line remains in service. Because it’s tethered, an operator has complete control, and can closely examine events of interest, such as a leaks, air pockets, and visual anomalies.

The tool is propelled by the product flow, requiring a flow velocity of only one foot per second, and is able to navigate in flows up to ten feet per second, with no disruption to service.

Sahara device

Sahara tool can be inserted into almost any existing tap 2 inches and greater

To insert the tool into an active pipeline, almost any tap 2 inches and greater can be used. As the tool enters the pipe, a small parachute or drogue is inflated by the flow velocity of the water. The parachute pulls the tool through the pipe, with the probe lighting the way with its onboard LED lighting system, highlighting any visual defects in the pipeline.

If the Sahara tool encounters any acoustic events—such as a leak—the operator can stop the tool at the exact point of the leak. At the same time, an above-ground operator locates the sensor, marking the exact leak location within plus or minus 18 inches (0.5 meter). This enables users to know in real time where the leaks are, and where repairs are needed.

Worker finding the exact spot for a issue reported during the inspection

Detects up to 4 times as many leaks as trunk main correlators

The tool can detect up to four times as many leaks as trunk main correlators because the acoustic sensor is brought right to the leak – pinholes, cracks, joint leaks – Sahara can detetct virtually any type of leak. In addition, the tool can detect air pockets in the pipeline, both visually and acoustically.

As the Sahara tool inspects the pipeline, it may encounter valves that connect a high pressure zone to a low pressure zone, and if one of those valves is not fully closed, Sahara can also detect the lack of isolation between zones during the inspection.

Visual anomalies detected during inspection

Detect leaks, air pockets and visual anomalies while mapping the pipeline path

The tool can navigate single bends without issue, but is limited up to 270 cumulative degrees of bends in a single survey.

While the video and acoustic inspection is taking place, the tool can also be used to map the pipeline path, providing a clear plan view of the pipeline with sub-meter accuracy. The beauty of the Sahara tethered platform is that it can provide a variety of pipeline condition information in real time, with no disruption to service, on all pipe types.

Houston Skyline

Enwave Houston deploys Sahara tool to quickly locate leak in chilled water line

In December 2015, Pure Technologies (Pure) was retained by Boyer Inc. to perform a Sahara inspection on a 24-inch Chilled Water Supply pipeline (CWS) and on a 24-inch Chilled Water Return pipeline (CWR) operated by Enwave Houston.

The purpose of the inspection was to locate a suspected leak on one of the dual lines that run parallel along the downtown core. Large cities often operate central chilled water plants to cool water that is then sold to building owners for use in air conditioning.

Tools on the surface before starting with the inspection

Insertions completed at night, with no traffic disruption or chilled water disruption

Boyer proposed two separate Sahara insertions during the planning phase. Pure completed both insertions at night over a two-day period for a total of 795 feet of pipeline inspected, with no traffic disruption or chilled water disruption. Acoustic data was collected and recorded during the inspections as the Sahara sensor traversed the main. The data was evaluated on site in real time to identify events associated with leaks and pockets of trapped air.

During the inspections, one (1) leak and zero (0) air pockets were detected. The leak was located 144 feet downstream from the insertion point with sub-meter accuracy. This allowed a pinpoint excavation to be made for repairs, minimizing disruption to downtown Houston traffic, and minimizing the contractor`s cost of excavation and road restoration.

Once again, the Sahara tool proved its worth.

It was a perfect day for an inspection.

Under a crisp blue sky, in the polders along a major motorway near Rotterdam, more than 40 water professionals from The Netherlands, Australia and the UK gathered to witness a unique project undertaken by the water utility Evides Watercompany.

The purpose of the project was to showcase the 24-sensor PipeDiver®, an innovative tool from Pure Technologies designed to assess and address large-diameter metallic pipelines.

As the second-largest water utility in the Netherlands, Evides was open to exploring new ways to reduce risks and extend the service life of their buried infrastructure.

Workers looking up

“Our first reaction is positive. PipeDiver proved to be a suitable tool for one of our most important inspection needs: corrosion of cement lined steel pipes. We are especially glad the tool was able to pass a butterfly valve, and to be inserted and extracted through 600mm manholes, as this greatly improves operability and cost effectiveness. Bart Bergmans

Project Manager, Infrastructure Asset Management, Evides Watercompany.

Inspected large-diameter steel pipeline runs along critical highway

The Evides TL2.60 pipeline is a cement-lined 800mm (31.5 inch) steel pipe, with 2.8 kilometers (1.7 miles) of the inspected pipeline running along an important highway connecting Rotterdam to The Hague. The transmission pipeline was selected for its criticality and some operational challenges that Evides wanted to address, including the presence of an inline butterfly valve that precluded other inspection tools from performing at this trial.

Prior to inspection, Evides created a series of predetermined defects made on a specific pipe segment in a research environment. The objective was to validate the tool against a range of known defects in a pipe with the same characteristics as the pipe inspected. During this process, all defects within the stated sensitivity were detected by PipeDiver at the precise location, providing confidence for the upcoming live inspection.

PipeDiver insertion

24-detector PipeDiver launches with eager anticipation and high expectation

All eyes were on the launch of Pure’s 24D PipeDiver tool, scheduled for the first of three identical runs, designed for data redundancy.

PipeDiver is a flexible, free-swimming condition assessment tool for pressurized water and wastewater pipelines. The video-equipped tool is ideal for critical pipelines that cannot be removed from service due to lack of redundancy or operational constraints.

Unlike more restrictive assessment tools, PipeDiver is a neutrally buoyant tool that flows with the product and easily navigates through most butterfly valves, tees and bends in the pipeline, delivering electromagnetic (EM) data for a variety of pipe type and materials.

24D PipeDiver tool developed for locating corrosion on metallic pipe

While the PipeDiver tool has traditionally been deployed on prestressed concrete pipe to identify and locate broken prestressing wire wraps, the 24-detector PipeDiver has been specifically developed for metallic pipelines. For the Evides inspection, the PipeDiver tool with 24 electromagnetic sensors was used to locate and identify steel pipes with anomalies associated with corrosion or reduced wall thickness.

“This inspection and related validations have shown that PipeDiver is able to deliver results that allow for well-founded replacement decision making of large-diameter, cement coated, steel pipelines.”

PipeDiver working inside a pipe

High definition camera records passage for all invitees to watch

Because the inspection exercise had so many invited utilities invested in the outcome, Evides provided inline cameras parked at both the butterfly valve and extraction point to record in real-time the passage of the PipeDiver. Thanks to the cameras, the world could watch.

The insertions went off without a hitch, and the PipeDiver sailed through the pipeline obstacle course with ease, gathering EM data along the route.

Results support long-term asset management decisions

Of the approximately 237 pipe sections inspected during the real inspection, four pipes were identified with anomalies indicative of cylinder wall loss.

After the inspection, three out of the four locations were dug-up to verify the reported defects, using non-destructive ultrasonic techniques. On each of the locations, defects were found, and the actual material loss was in the range reported by Pure Technologies.

Overall, the results proved the worth of PipeDiver as an advanced condition assessment tool able to deliver precise, actionable data on metallic pipes. The exercise showed the PipeDiver tool as a cost-effective solution versus methods that have operational constraints or require a shutdown or dewatering, or in this case, taken out of service.

This Evides inspection marked the first condition assessment of metallic pipe using the 24D PipeDiver in Europe, an exercise that confirmed the efficacy of the tool’s sensor technology and validated once more the effectiveness of the platform to inspect pipelines.

Using pipeline condition assessment platform like the PipeDiver tool can help utilities like Evides to support long-term asset management decisions on their underground infrastructure. The water world couldn’t agree more.

Workers from 14 utilities learning about new technology

14 global utilities in attendance

The PipeDiver project offered the opportunity for 14 of the most forward utilities from around the world to share experiences and learn about innovative technologies used to assess and address large-diameter metallic pipelines. The utilities included:

  • From Australia: Yarra Valley Water, Seq Water, Unity Water, Gold Coast Water, Water Corporation, Sun Water, SA Water
  • From the United Kingdom: Severn Trent Water, Anglian Water, Welsh Water
  • From the Netherlands: Waternet, Vitens, WML, PWN, Evides Watercompany

24-Detector PipeDiver tool

Advanced PipeDiver tool developed for condition assessment of metallic pipes.

Pure Technologies (Pure) never says no to an engineering challenge. If a client has a particular pipeline assessment or monitoring challenge to overcome in order to make a rehabilitation decision, we’ll do whatever it takes to help our clients solve the problem.

Pure Technologies embraces research and development (R&D), with a strong dedication to continually develop new technologies and improve upon existing inspection systems. This attitude of taking a winning platform and making it better was demonstrated again with the introduction of the optimized PipeDiver, an advanced, multi-sensor tool developed specifically for the condition assessment of metallic pipes within pressurized pipe networks.

PipeDiver inspection tool operates while the pipeline remains in service

As a technology platform, PipeDiver is a versatile, free-swimming condition assessment tool that operates while the pipeline remains in service, often providing an easier and less costly alternative than inspection methods that require a shut-down or dewatering.

Two men working with a PipeDiver device

The PipeDiver platform is ideal for critical, large-diameter lines that cannot be removed from service due to operational constraints or lack of redundancy. The PipeDiver tool requires only a 12-inch access, and can be deployed on pipelines that range from 16 inches up to 120 inches.

The tool can be deployed, collect information on pipeline condition and extracted in a single mobilization.

As the PipeDiver platform can be equipped with a closed circuit television (CCTV) camera, the tool is able to record and deliver video images from the inside of the pipeline (quality depends on water clarity).

PipeDiver Cammera working

Tool able to navigate most butterfly valves, tees and pipeline bends

To begin an inspection, the tool is balanced to be neutrally bouyant and inserted into a pressurized or depressurized pipeline through a tap connection, or an existing access point. The tool travels with the product flow, and utililzes flexible petals to navigate butterfly valves, tees and bends in the pipeline.

Originally designed for use in pressurized concrete cylinder pipes (PCCP), the tool has specialized electromagnetic sensors (PureEM) to identify and locate broken prestressing wire wraps, (one of the main structural components and failure modes of a prestressed concrete pipe).

Historically, technologies available to assess the condition of metallic pipe have been full diameter tools (“Smart Pigs”) unable to traverse most water or wastewater pressure pipelines due to inline valve restrictions and limited access for insertion and retrevial of a full diameter tool. These challenges led Pure’s R&D to develop the specialized PipeDiver for metallic pipes, equipped with advanced electromagnetic technology to identify localized areas of wall loss.

The PipeDiver electromagnetic (EM) technology can also be used in bar wrap pipelines to identify broken bars and steel cylinder damage, the two main structural components bar wrap pipe.

PipeDiver device inside a pool of water

Utilities Kingston welcomes PipeDiver to assess its metallic pipeline

Since its introduction, the optimized PipeDiver platform has been deployed for various projects in Europe, Canada and the U.S.

This year Utilities Kingston agreed to pilot the new technology as part of a comprehensive condition assessment on its Dalton Avenue (North End) Pump Station Force Mains. The pipelines are both approximately 1,550 meters long and follow a parallel route for approximately 1 kilometer.

The older of the two force mains is 450 mm (18-inch) in diameter, constructed of ductile iron built in the late 1950s, and had failed several times over its lifetime. The newer of the two force mains is 600 mm (24-inch) in diameter, built from an unspecified concrete pipe from the early 1960s. As the pipe material specifics were still unknown at the time of the inspection, the Pure elected to conduct a PipeDiver run to accommodate both possible types of pipe material – assumed by all to be bar wrapped pipe (BWP) and prestressed concrete cylinder pipe (PCCP).

Force main defects can vary from one pipe material to another

During a forensics exercise on the 600 mm force main using earlier PipeDiver technology, it was revealed that the actual pipe material included 102 suspected metallic pipes, which were not identified as such in the original plan and profile drawings.

This included ductile ironsteel and unexpectedly, reinforced concrete pipe (RCP), which is not usually used in pressurized environments. Electromagnetic inspection of the RCP can only reveal anomalies on the circumferential cage and not the longitudinal bars.

Inserting the PipeDiver device through an inspection hole

Optimized PipeDiver tool deployed in wastewater

Pure deployed its optimized PipeDiver tool to conduct a quality analysis of the 450 mm pipe. The purpose of the inspection was to locate and identify steel and ductile iron pipes that have indications of wall loss.

This marked the first condition assessment of metallic pipe using the optimized PipeDiver in wastewater, an exercise that confirmed the validity of the tool’s sensor technology.

Results lead to actionable information regarding rehabilitation

Of the 650 pipes inspected with the PipeDiver tool, a total of 55 pipes in the 450 mm Dalton Avenue Pump Station Force Main had electromagnetic anomalies characteristic of localized wall loss.

The data collected gave Utilities Kingston a better understanding of their real, not assumed assets. The results, which included a DIP risk of failure analysis, were used to complete a structural evaluation of the force mains, and have provided UK with actionable information regarding any necessary repairs or rehabilitation.

PipeDrive device revision after the inspection has finished
City of Vancouver from the air

With its Pacific Ocean entranceway and towering backdrop of snow-dusted mountains, it’s no wonder the City of Vancouver ranks among the most laid-back, beautiful cities in Canada, and indeed, the world. Water is in its blood.

This spring the coastal seaport city retained the services of Pure Technologies (Pure) to perform a condition assessment and risk analysis of the Powell-Clark Feeder Main, part of the city’s water system that daily delivers 360-million liters of high-quality water throughout the city. During the course of the assessment, the inspection team had to deal with unexpected challenges, but in true West Coast spirit, collaboration between the inspection teams led to success.

Over five days in March 2016, Pure performed an electromagnetic inspection of the subject pipeline utilizing its free-swimming PipeDiver® platform, and an acoustic inspection using its free-flowing SmartBall® inspection tool. Pure also monitored this feeder main using a Transient Pressure Monitor for three months prior to the previous two inspections.

PipeDiver device

PipeDiver inspection identifies electromagnetic anomalies

The Powell Street Feeder Main is comprised of prestressed concrete cylinder pipe (PCCP), ranging from 750 to 900-mm in diameter. The Clark Drive Feeder Main consists of 750-mm of bar wrapped pipe (BWP).

The PipeDiver electromagnetic inspection covered a cumulative distance of 4.57 kilometers and spanned 676 pipes. Unlike more restrictive assessment tools, PipeDiver is a flexible, free-swimming tool that flows with the product and is able to easily navigate through most butterfly valves, apertures and bends in the pipeline, delivering electromagnetic (EM) data for a variety of pipe type and materials.

EM technology provides prestressing wire-break estimates on each individual section of PCCP, which is the best indicator that this type of pipe will fail. This allows for one deteriorated pipe to be identified within an entire pipeline that is in good condition overall, and also provides the baseline condition on all pipes in the inspected distance.

Analysis of the data obtained during the inspection determined that one (1) pipe (less than one percent of the pipeline) in the 750 mm Powell-Clark Feeder Main displayed electromagnetic anomalies consistent with 30 broken prestressing wire wraps. This is well below the average distress rate observed by Pure Technologies in PCCP pipelines, which is 3.8 percent of pipes in structural distress.
SmartBall with case and insertion tools

SmartBall inspection tool used to locate leaks and gas pockets

In addition to the EM inspection, Pure also performed a SmartBall inspection to identify and locate leaks and pockets of trapped gas along the pipeline.

Unlike traditional external listening tools with limited success on large diameter pipes, free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls, it can inspect every inch of a water main to detect leaks and gas pockets.

The SmartBall tool was inserted into the pipeline through a flange access and acoustic and sensor data was collected and recorded as the tool traversed the pipeline. At a distance of 5.8 kilometers, (only 470 meters from the end of the inspection run), the tool stopped tracking.

Crews from the City and Pure put their heads together to solve the problem.

ROV camera shows a tool cart inside the pipe

Collective thinking clears the debris and all is well

By analyzing data from the earlier PipeDiver inspection, Pure determined that unknown debris likely lodged the SmartBall tool.

The City excavated and modified a tap to allow Pure to access the pipeline with a submersible ROV (equipped with a camera) to retrieve the SmartBall tool and examine the debris, which turned out to be an old forgotten tool cart. The cart and SmartBall tool were extracted, the data was evaluated and considered valid, and all was good.

From the SmartBall data, Pure Technologies detected three (3) anomalies characteristic of leaks and zero (0) acoustic anomalies characteristic of pockets of trapped gas.

While no gas pockets were identified during this inspection, two (2) instances of entrained air were identified as migratory acoustic anomalies, and flagged for future inspection, as they may develop new pockets of trapped gas.

Validated results help the City manage its infrastructure

In spite of the cart debris blocking the SmartBall tool during the last few meters of its long inspection journey, the data collected during the pipeline assessment was analyzed as valid.

When combined with the results from the PipeDiver EM inspection, the condition data will be used as part of the City of Vancouver’s asset management initiative and allow for proactive measures in the assessment and management of their infrastructure.

West Palm Beach Aerial View

The City of West Palm Beach (WPB) makes a concerted effort to engage its citizens.

As one of the three largest cities in South Florida, WPB is a vibrant, growing waterfront community with a population of more than 100,000. Since 1974, WPB has experienced exponential growth in its population and correspondingly, in its wastewater management needs. During this time, WPB has continuously upgraded its pumping and treatment processes based on advances in regulations and technology.

In the evolution of its force main strategy, WPB has undertaken a variety of initiatives to manage its network to reflect the needs of its community. This ties into an overall strategy by dealing with rehabilitation needs proactively to prevent costly system failures while planning the rehabilitation and assessment of an entire system over the long term.

West Palm Beach bucks the trend to replace based on age of system

Historically, management of a force main network has been based on the general age of the system without specific information of the system in relation to its normal and extreme weather operation.

Bucking this trend, WPB takes an enlightened view to the management of its wastewater network, with age of the system not an automatic reason to replace or rehabilitate. While complete replacement would be ideal, the cost associated with full scale replacement is unfeasible. Ratepayers demand fiscal responsibility and are reluctant to sign over blank cheques to their utilities.

As a testament to its proactive stance, WPB has completed the first phase of a condition assessment, design and rehabilitation program of its force main network, which includes a nearly six-mile section of pipeline that conveys wastewater from Lift Station 22 to the East Central Regional Water Reclamation Facility (ECRWRF). Comprised of 42-inch and 48-inch lined cylinder pipe (LCP) and 48-inch embedded cylinder pipe (ECP), this force main, constructed in 1974, is considered the most critical piece of underground infrastructure for the City’s wastewater system.

Staff working at insertion site

In 2007, WPB conducted acoustic monitoring of the ECRWRF Force Main to determine what areas were deteriorating, but the results proved inconclusive.

In 2015, with the evolution of condition assessment techniques, WPB retained Pure Technologies to conduct a follow-up inspection using pressure monitoring and non-destructive inline assessment technologies.

For WPB, the process included examination of the ECRWRF pipeline from a wide variety of parameters. For example, manufacturing standards from the original force main design were structurally analyzed in contrast to current design standards.

The program examined current operational and maintenance practices, monitored air release valves and looked at pressure profiles based on the multiple pumping station connections to the force main. By deploying acoustic and electromagnetic technologies from Pure Technologies, WPB identified high priority areas based on gas pockets and structural stress along the force main route. WPB combined this information with rehabilitation and replacement strategies to define the second phase of the management process.

SmartBall® inside a pipe

First inspection: SmartBall® acoustic leak and gas detection

In February, Pure used its SmartBall inspection platform to conduct acoustic leak and gas pocket detection on the line. Unlike traditional external listening tools with limited success on large-diameter pipes, free-flowing SmartBall technology provides a high degree of accuracy, since as the ball rolls, it can inspect every inch of the main to detect leaks and gas pockets.

The SmartBall tool was inserted into the pipeline through a hot tap and acoustic data was collected and recorded as the tool traversed the pipeline, where it was later retrieved at a bypass grit chamber.

PipeDiver® electromagnetic inspection

Next: PipeDiver® electromagnetic inspection

Subsequently, Pure deployed its free-swimming PipeDiver platform to perform an electromagnetic (EM) inspection to locate broken prestressing wire wraps in the LCP/ECP pipe. Unlike more restrictive assessment tools, PipeDiver is a flexible, free-swimming tool that flows with the product and is able to easily navigate through most butterfly valves, apertures and bends in the pipeline, delivering electromagnetic (EM) data for a variety of pipe type and materials.

EM technology provides prestressing wire-break estimates on each individual section of PCCP, which is the best indicator that this type of pipe will fail. This allows for one deteriorated pipe to be identified within an entire pipeline that is in good condition overall, and also provides the baseline condition on all pipes in the inspected distance.

Results guide the success of the program

During the SmartBall inspection, zero (0) leaks were detected, while 23 recordings were indicative of entrained gas and gas slugs.  Of the 1,682 pipes inspected by the PipeDiver tool, approximately 10 percent of pipes displayed electromagnetic anomalies consistent with broken prestressing wire wraps.

Overall, the condition assessment found the majority of the pipe to be in good condition. Pressure monitoring identified intermittent pressure surges within the design standards of the force main. However, this effort elevated the City’s awareness of the relationships between pressure management and the structural integrity of the pipeline.

Based on the completed assessment, the City implemented a two-year project delivery timeline for extending the service life of the force main for another 40 to 50 years.  The schedule included a comprehensive community outreach program that has residents onboard with the phased-in design and construction approach.

SmartBall extraction and retrieval

Tarrant Regional Water District (TRWD) and Pure Technologies U.S. (Pure) have a long history of working together to keep the water transmission mains in the Dallas-Fort Worth (DFW) area in good operating condition.

The partnership began 17 years ago with mutual development of electromagnetic technology to inspect prestressed concrete cylinder pipe (PCCP). One of Pure’s first electromagnetic inspection prototypes was developed (with funding assistance from American Water Works Research Foundation [now Water Research Foundation (WRF)], commercialized (with assistance from TRWD) and first pulled through TRWD’s pipeline on a little red wagon!

Inspection Prototype

TRWD is one of the largest raw water suppliers in DFW with large-diameter pipelines that transport water from the East Texas Cedar Creek and Richland-Chambers Reservoirs. TRWD provides water to almost two million people and spans an 11-county area in North Texas.

Electromagnetic Inspector

Electromagnetic technology platforms recognized around the world

Since 1999, TRWD has utilized Pure’s advanced inspection and condition assessment services to evaluate than 240 miles of PCCP. Over the years, TRWD has deployed a variety of inspection platforms to determine the condition of their critical supply lines. This includes PipeDiver®, a free-swimming electromagnetic inspection technology, Sahara®, an acoustic leak and gas pocket detection tool, and a manned electromagnetic tool equipped with PureEM® to collect full circumferential data of the pipe wall.

The condition assessment data is compiled with a Geographic Information System (GIS) deliverable, which provides TRWD with detailed information that is used to implement a targeted pipeline repair and replacement strategy.

TRWD utilizes Pure Technologies’ cost-effective Assess and Address® approach to target specific pipes for repair or replacement that are near the end of their service life, as opposed to replacing entire sections of pipe in good condition. In addition, this proactive approach allows TRWD to document significant savings over a complete pipeline replacement strategy.

Since 2000, a total of 271 pipes have been replaced during planned maintenance based on the results from Pure inspections.  As a result, TRWD has noticed a dramatic decline in failures since the late 90s doing a risk-based prioritization and replacement/rehab program, in addition to implementing cathodic protection, pressure transient surge reduction measures, and pipeline protection measures from external loads.

TRWD is extremely proactive when it comes to understanding their pipeline infrastructure. They take pride in their ability to locate and repair leaks, and repair or replace damaged pipes during routine maintenance schedules – rather than in emergency situations.

Tech inspecting a pipe with a tool

Over the past decade, several high profile oil and gas pipeline failures have shown that the consequences of a rupture can be extremely severe for both the environment and human life, and can result in billions of dollars in remediation costs. Because of all these negative consequences, governments have made it mandatory to conduct routine inspections on these assets to prevent catastrophic events.

Today, the most common form of pipeline assessment is inline inspection (ILI) with smart pigs. These pigs flow with the product, collecting data on the condition of the pipe wall. When these tools are operating in a live pipeline, it is important to track their precise location and speed, as a lost or stuck pig can obstruct product flow, cause unwanted service disruptions or damage the pipeline.

A common misconception about pig tracking is that a run always goes as planned.  In the majority of runs, nothing unexpected will occur, but there have been a few cases where a minor event can quickly derail the smoothest of jobs, resulting in cost escalations and unnecessary hassle for the pipeline owner. By taking proper precautions and using advanced tracking technology, pipeline owners can ensure that they are prepared for any unexpected event that may occur.

Traditionally, pigs have been tracked by a single technician equipped with a standard geophone to identify the pig passing. This method can be extremely challenging and unreliable, and can result in a lost pig. In order to mitigate the risks of conventional tracking, owners can use remote tracking technology which provides greater reliability and accuracy.

Remote Tracking Prepares Asset Owners for the Unexpected

Remote tracking combines above ground markers (AGMs) equipped with multiple sensors with remote communication technology. This ensures that the pig is being tracked using more than one sensor, which is significantly more reliable than a standard geophone. In addition to tracking with multiple sensors, pipeline owners and ILI vendors are provided with a record of each passage that is downloaded from the AGMs. This record shows the signal of the pig passage, along with other information such as time and speed. The AGMs provide snapshots into a software where they can be used for real-time tracking of the pig’s position, speed, and estimated time of arrival. Pipeline owners can be sure that the results are accurate because the AGMs constantly record data to confirm pig passages when they are turned on.

If a pig gets stuck, the AGMs will know if the pig has not passed a tracking location, making it much easier for field technicians to retrieve it in a timely manner, so no damage is caused to the pipeline. Remote tracking provides reliable information and when unexpected events occur, enables pipeline owners to be better prepared for any issues that may arise.

To learn more about remote tracking and its benefits, download the white paper below.

Sensor with remote communication technology

*Published in World Pipelines Magazine

Oil and gas pipelines have been around for well over a century, and some of the earliest constructed are still in service today.  Although early pipelines were made of wood, and in the past few decades plastics and composite materials have increased in popularity, the vast majority of pipelines in service today are constructed with steel.

Like any pipe material, steel pipe has its downfalls. Steel has a propensity to dent, buckle, corrode and crack when exposed to the environment.  Steel pipeline’s carrying combustible hydrocarbons are buried underground with typically ~1 meter (3 feet) of cover to protect them.  In order to mitigate corrosion, pipelines are covered with a protective coating, utilize cathodic protection (CP), and have their pressure regulated to reduce crack formation and propagation.

Despite all of the design innovations made over the past century, it has not been enough to prevent failures – even the most recently constructed pipelines.  Weather cycles, frost heaves, and road loadings cause physical damage to the pipeline and protective coating.  Operational errors and material defects cause the steel to succumb after years of relentless pressure cycles from the pipeline product itself.  Therefore, proactive pipeline inspections are needed to identify defects, before they cause a leak or rupture.

Pipeline integrity can be validated and assessed using three primary techniques: hydro-testing, the use of Inline Inspection (ILI) tools, and Direct Assessment.

Hydro-testing

Hydro-testing became common practice for pipelines in the 1940s. The process involves taking the pipeline out of service and purging the product, then the pipeline is pressurized above the maximum operating pressure (MOP) with the intent to determine the ability to operate the pipeline at MOP.  While hydro-testing is still widely used today, there are several drawbacks to the process. The water used in hydro-testing is considered hazardous material after being used, meaning owners incur the additional risk and cost associated with disposing of the water after testing. The information gained from the test is also limited in that it provides no information of the actual condition of the pipe, coating, or surrounding environment.

Hydro-testing can also promote internal corrosion of pipelines, especially if the water used is not properly treated for microbiologically influenced corrosion (MIC) and chlorides. Internal corrosion usually occurs if the pipeline is not properly cleaned and dried after the test.  Hydro-testing can also result in pressure reversals, which worsen the integrity of the pipeline [1].  Finally, the pipeline may be required to be out of service for a significant amount of time, resulting in a significant loss of revenue.

Inline Inspection

ILI tools – which are commonly referred to as smart pigs – were developed in the 1960s and commercialized in the 1970s.  These tools are designed to survey the conditions of the pipeline wall with limited disruption and can identify and quantify the corrosion and cracking in steel pipelines [2].  Magnetic flux leakage (MFL) and ultrasonic testing (UT) are common ILI tools used widely by owners today.

ILI is a significant part of pipeline integrity management, and promote safe, efficient and cost-effective pipeline operation [2].  However, it is important to remember that ILI is just a subset of a family of inspection tools used to verify pipeline fitness for service.  As with any inspection technology, ILI tools have a threshold for detection – the tools are unable to reliably detect anomalies that are below their design specifications’ detection ability. Also, internal pipeline inspections are primarily reactive, requiring the damage or wall loss to occur before defect detection is possible.

Direct Assessment (DA)

The most recently developed solution for pipeline integrity management is Direct Assessment (DA), which is a structured, iterative integrity assessment protocol used by pipeline operators to assess and evaluate the integrity of their pipelines.

Adoption and demand for DA is increasing in modern integrity programs due to more stringent industry regulations, aging pipeline networks, limitations of alternate inspection techniques, and the fact that roughly 70 percent of pipelines within North America are difficult to pig.  Direct assessment surveys provide pipeline owners with important information on both the pipeline’s condition and its surrounding conditions, both of which can lead to degradation and eventual failure.

The Stages of Direct Assessment

It should be noted that geotechnical, dent, and buckle threats are not specifically addressed with any of the DA techniques.  All DA protocols are four-step iterative processes which include a Pre-Assessment, an Indirect Inspection, a Direct Examination and a Post-Assessment.  Inspections involve the integration of as much pipeline available integrity data as possible, which includes physical characteristics and operational history, historical and multiple indirect inspections, and direct pipe surface examinations.

In the pre-assessment step, historic and current pipeline data is collected to determine whether DA is feasible, define DA regions, select indirect inspection tools and determine if additional integrity data is needed.

The second step in DA methodology involves the use of non-intrusive and aboveground techniques. These tools assess the effectiveness of the coating and cathodic protection for pipeline external corrosion assessment (EDCA an ECCDA), and predictive modelling, or critical angle calculations for pipeline internal corrosion assessment (ICDA) to identify and define areas susceptible to internal corrosion.

For external corrosion assessment, the state of cathodic protection, coating and soil resistivity are critical factors in determining high-risk areas. For internal corrosion assessment, fluid flow, mass transfer, solid accumulation, mineral scales, corrosion products, and MIC are critical components [3].  For stress corrosion cracking, critical factors include operating stresses, operating temperatures, distance from a compressor station, age of the pipeline, and coating type.

The direct examination step involves the analysis of pre-assessment and indirect inspection data to select sites for excavation and examination of pipe surface. This process validates the inspection data and provides a first-hand evaluation of the pipe surface and surrounding environment.

Finally, the post-assessment phase involves the analysis and integration of integrity data collected from the previous three steps to assess the effectiveness of the DA process and determine the necessary reassessment intervals.

There are six DA standards developed by National Association of Corrosion Engineers (NACE) and they include:

2002 -NACE SP0502-2010 ECDA (External Corrosion Direct Assessment)

2004 -NACE SP0204-2008 SCC-DA (Stress Corrosion Cracking Direct Assessment)

2006 -NACE SP0206-2006 DG-ICDA (Dry Gas Internal Corrosion Direct Assessment)

2008 -NACE SP0208-2008 LP-ICDA (Liquid Petroleum Internal Corrosion Direct Assessment)

2010 -NACE SP0110-2010 WG-ICDA (Wet Gas Internal Corrosion Direct Assessment)

2010 -NACE SP0210-2010 ECCDA (External Corrosion Confirmatory Direct Assessment)

DA is also covered in ASME B31.8S (Section 6.4).  In the United States, DA is covered in US Code of Federal Regulation CFR 49 Part 192.923 (for natural gas pipelines) and 195.888 (for liquid hazardous pipelines).  It is now one of the three accepted inspections (ILI and Hydro-testing being the other two) allowed for oil and gas pipelines.

Identifying Pipeline Anomalies Using Directing Assessment

When completing a DA inspection, there are three types of anomalies that owners are aiming to identify:

1.         External Corrosion (EDCA and ECCDA)

2.         Internal Corrosion (dry gas, wet gas, and liquid petroleum ICDA)

3.         Stress Corrosion Cracking (SCCDA).

Due to the serious consequences of corrosion and leaks in underground pipelines, external corrosion direct assessment (ECDA), and external corrosion confirmatory direct assessment (ECCDA) – as described in ANSI/NACE SP0502 and NACE SP0210 – were developed in an attempt to proactively prevent external corrosion and ensure the integrity of oil and gas pipelines that are difficult to pig.

ECDA is a continuous improvement process intended to identify and address locations at which corrosion activity has occurred, is occurring, or might occur. For instance, ECDA identifies areas where coating defects have already formed, and can ascertain where cathodic protection is insufficient and corrosion is possible, before major repairs are required.

The success of any ECDA requires strong knowledge of the soil/environment, pipeline material, coating, cathodic protection, and foreign/interference current on the pipeline. Also, the accurate selection of susceptible areas for external corrosion relies on using at least two complementary advanced aboveground inspection techniques. These aboveground indirect inspection techniques may include: direct current voltage gradient (DCVG) or alternating current voltage gradient (ACVG) surveys, a cathodic protection close interval potential survey (CP CIPS), alternating current—current attenuation (ACCA) and side drain (for bare or ineffectively coated pipelines) surveys. Normally these aboveground inspections are used in conjunction with pipe locating.

The development of internal corrosion in pipelines is partly because of its complex nature and interaction between constituents that are found in transported gas and liquid products (e.g., oxygen, carbon dioxide, hydrogen sulfide, chloride, bacteria, etc.). When in the presence of water, these contaminants can lead to conditions conducive to the occurrence of internal corrosion. The susceptible locations for internal corrosion are usually where liquids, solids and gas accumulate. In order to ensure that susceptible locations along the pipeline are prevented from internal corrosion, internal corrosion direct assessment methodology is implemented.

Internal Corrosion Direct Assessment (ICDA) methodology has been developed to verify pipeline integrity, especially for pipelines that are not able to accept inline inspection (ILI) tools. ICDA includes Wet Gas Internal Corrosion Direct Assessment (WG-ICDA), Dry Gas Internal Corrosion Assessment (DG-ICDA) and Liquid Petroleum Internal Corrosion Direct Assessment (LP-ICDA). WG-ICDA (NACE SP110-2010) is used in pipelines that assumes that water, or a combination of water and hydrocarbons can be present in the pipeline. It is intended for onshore and offshore systems where liquid to gas ratio is small. It tends to identify locations in the pipeline where corrosion is expected to be severe. DG-ICDA (NACE SP206-2006) is applicable to pipelines that transport gas that is normally dry, but may suffer infrequent upsets, which may introduce water to the pipeline. LP-ICDA (NACE SP208-2008) is employed to assess the susceptibility of internal corrosion on pipelines that transport incompressible liquid hydrocarbons that normally contain less than 5 percent base sediment and water. The success of any ICDA process is dependent on using an accurate corrosion model to predict a precise elevation profile in order to determine susceptible locations for internal corrosion.

DA technology has also proven successful in stress corrosion cracking direct assessment (SCCDA), offering pipeline operators a comprehensive pipeline integrity management portfolio. SCCDA (referenced in NACE SP0204-2008 and ASME B31.8S) is a proactive structured process that seeks to improve pipeline safety by assessing and reducing the impact of stress corrosion cracking. Stress corrosion cracking can occur at neutral or high pH when susceptible pipeline material is exposed to stress, specific susceptible temperature, and a corrosive environment.

The Benefits of Direct Assessment

Direct Assessment is non-intrusive and inspections can be completed during normal operation of the pipeline.  DA is also a proactive integrity management tool that can find anomalies before they become critical defects, while traditional ILI tools are reactive in that they identify existing pipeline damage.

While hydro-testing and ILI tools are an important part of integrity management, the development of DA provides pipeline owners with another solution to identify at-risk areas of pipe before they become a major problem. A combined integrity approach that employs DA can help pipeline owners ensure containment and prevent costly, reputation-harming pipe failures.

References

1.    Pipeline Research Committee, American Gas Association, NG-18 Report No. 111 (Nov. 3, 1980)

2.    NACE 35100, In-Line Inspection of Pipelines, NACE International, May 2012

3.    NACE Training Course, Direct Assessment, NACE International, November 2012

*Published in World Pipelines Magazine

The oil and gas pipeline industry has been under close scrutiny for a long time. It leads the way as one of the most regulated industries in the world, and for good reason.  With so many safety-related, social and environmental factors at stake, comprehensive regulation ensures rigorous standards for the design, construction, operation and maintenance of O&G pipeline systems.

Global economics and political activism also play a role in shaping today’s conversation about pipelines. In North America, public debates about the Keystone XL Pipeline have dominated much of the recent news, compelling operators to vigorously participate in the discussion and advocate their integrity management programs. Although Keystone has been put on hold, social capital can assist in getting projects of this magnitude on the radar again.

Through it all, much of the dialogue has focused on the industry’s commitment to protecting communities and the environment from risk by means of rigorous pipeline integrity management programs. As a result, the requirement for increased pipeline safety drives innovative research into improving the sensitivity and reliability of inline inspection (ILI) tools.

Most operators already deploy trusted inline technologies that detect structural deterioration and help maintain pipeline integrity. However, with pressure mounting from stricter regulation, increased operational costs, commodity price-driven budgetary pressure, and often limited available resources, operators face an increasing number of challenges, including vigilance from highly engaged consumer groups.

Although the pressure to perform is greater than ever, operators are responding appropriately with greater confidence in modern technologies to assist in the operation and monitoring of their pipeline systems.

Better ILI tools instill better confidence in containment

To have confidence in the pipeline, operators must have confidence in the capabilities of ILI tools to detect small anomalies that could lead to potential failures.  They must also trust the reliability and interpretation of the data, knowing with as much certainly as possible that the depth, size and location of the pipe wall anomaly is correct.

Overall the news is good. Between 2002 and 2013, Canadian Energy Pipeline Association (CEPA) member companies were able to transport oil and natural gas with a 99.999 percent safety record. While that statistic sounds impressive, headline-grabbing pipeline incidents do occur, (in 2014 there were 122 natural gas and liquid releases) and when that happens, the repercussions can undo years of containment management trust and goodwill.

While the oil and gas industry boasts a remarkable safety record, a reliance on conventional tools limit the near perfect record.  As much as the technologies have been refined, regulators have noted that inline inspections don’t pick up all defects, and expedient follow-through often depends on the people analyzing the data and planning repairs, a process that can take months.

“Despite their sophistication, the detection capabilities of inline inspection tools have limitations,” the US National Transportation Safety Board noted in its report on the 3.3-million-liter 2010 spill in Michigan.

Limitations of conventional ILI inline inspection technologies

The oil and gas pipeline industry has access to an extensive toolbox of technologies for robust integrity programs. Some tools address cracks or corrosion issues, while other tools focus on stress, pressure and product containment. Cost, resolution, reliability, data analysis speed – each technology has its own strengths and limitations, with no silver bullet as the single solution for collecting pipeline condition information.

For example, there is a strongly-held belief in hydrostatic testing as a reliable method to test a pipeline’s integrity. One of the earliest inspection techniques, hydrostatic testing determines if a pipeline can hold its operating pressure. A form of destructive testing, hydrostatic inspection involves purging the product, flooding the line with water, pressurizing it to a predetermined level and maintaining the pressure for a period. Based on the results, detected anomalies in pressure, volume and density can be a precursor to leaks.

Critics however, argue and have quite effectively demonstrated that the hydrostatic tests lack the ability to monitor ongoing corrosion or cracking and that the high pressure environment can exacerbate previously small defects, increasing risk of future rupture.

Smart pigs for detecting large cracks and corrosion

Unlike hydrostatic testing, which is often conducted on pipelines for acceptance testing or for pipelines recently rehabilitated, pigging is the more commonly accepted method of testing pipeline integrity.

While newer “smart” pigs have an excellent reputation for accuracy, their efficacy is often limited to detecting corrosion and cracking that exceeds the threshold for detection of the technology.  Small corrosion pits and cracks, especially cracks grouped in a colony, can pose a challenge to most conventional ILI pigging devices.

The various ILI technologies are sensitive to axial or circumferential defects, and each has limitation for minimum aspect ratios or cross sectional wall loss area before the ILI tool can report the anomaly.  It is also possible to have cracks and wall loss pits that are in close proximity to girth welds, long seams, and other features in the pipe, which can mask the defect, preventing the ILI tool from properly identifying and sizing.  As a result, it is possible to have leaking cracks and corrosion pits that are too small to be sized and reported from conventional ILI.

Not all lines are piggable

Some pipes are more suitable for pigging than others. While most oil and gas transmission lines were built in long straight sections suitable for pig runs, sections with small diameter pipe and small bend radius pipe configurations can limit many ILI tools.  Lines with expansion loops and miter bends, and in the case of natural gas lines, those with reduced port valves, are factors that can prohibit or restrict the traversing of online tools.

Mass balance measurement and other leak detection tools

To make up for the limitations of conventional ILI technologies, operators often deploy measurement methods and leak detection technologies to complement their integrity programs.

Mass balance is a means of detecting leaks by measuring the mass of product entering the pipeline compared to the mass exiting the pipeline. The limitation for detecting small leaks is the sensitivity of the mass meters being used (2-4% accuracy for conventional orifice meters and 0.25% for turbine meters), and the fact that the product temperature and pressure changes as it moves through the pipeline.

While mass balance is a means to determine leaks, it is also recognized that making actual measurement of mass from volume (through a meter) at different temperature and pressure going in versus coming out of the pipeline, in real time, is difficult, and not very precise or sensitive to small leaks.

As a result, a leak has to release more product than the total tolerance of the mass balance system before a positive leak/release event is alarmed.

Acoustic leak detection

Minute cracks are often preliminary indicators of potential small leaks that produce acoustic emissions at levels often unrecognizable over background noise.

Acoustic leak detection can be conducted with geophones/hydrophones, comparators and acoustic fiber optic techniques, and each of these acoustic tools is subject to different background noise limitations to determine leak detection thresholds.  Not only can these tools have limitations to prevent small leak detection, the expense from installing permanent acoustic systems may reduce the practicality of these technologies.

Emerging technologies on the horizon

To complement hydrostatic testing, conventional pigging tools, and leak detection technologies, the oil and gas industry is evaluating a growing number of emerging external confirmation of containment technologies. These include vapour-sensor systems, hydrocarbon-sensing cables that change in the presence of hydrocarbons, internal pressure wave based tools and fibre-optic based systems that detect temperature changes and acoustic signals associated with leaks.

While these technologies offer hope for more precise surveys, they have yet to be universally accepted or proven. Many are still under development and often require economically impractical installation requirements.

However, there is an innovative, multi-sensor ILI platform that has been used in integrity management programs since 2006, gaining the attention of major pipeline players who have tested the platform, which has now been used on over 25,000 kilometers of pipeline in total.

Introducing SmartBall® technology for Oil & Gas pipelines

To provide a realistic snapshot of a pipe’s condition, many proactive operators are deploying SmartBall technology,  a free-swimming multi-sensor tool for long inspections of piggable and difficult to pig liquid and gas pipelines 4 inches and larger. This advantage makes the ball-shaped tool an excellent choice for traversing not just standard diameter pipes, but for smaller diameter liquid lines and for gas pipelines with loops and frequent sharp bends and heavy wall fittings.

During an inspection, the SmartBall sensors collect acoustic, pressure, temperature, magnetic and inertial data from inside the pipeline.

Primary applications for the SmartBall tool

SmartBall surveys can be conducted independently, at regular intervals, as part of a routine pipeline integrity management program, or as a value-add to inspection programs along with hydro-testing, ILI, or direct assessment.

The tool is launched and retrieved at existing pig traps and is tracked using proprietary acoustic receivers and/or Armadillo pig tracking boxes (AGMs). The location data from acoustic receivers and tracking boxes is used during data analysis to locate any anomalies.

SmartBall technology has three primary applications, and the multi-sensor tool can provide a variety of pipeline data.

1. Confirmation of Containment

Regular confirmation of containment surveys are an important part of integrity management as leaks are often a preliminary indicator of pipe failure.

Unlike conventional leak detection systems, confirmation of containment with SmartBall supplements these systems. The SmartBall tool directly passes leaks, and is therefore capable of detecting losses as small as 150 mL/min, which can be several orders of magnitude more sensitive than conventional methods.

SmartBall surveys can also complement regular ILI surveys by addressing potential pinhole anomalies that have aspect ratios below the reporting threshold of ILI systems.

2. Pressure and Temperature profiles

As the SmartBall is rolling and not sealing against the pipe ID, as conventional pigs do, the tool can also record precise pressure and temperature profiles. The SmartBall platform can be deployed in gas pipelines, where pressure and temperature profiles can be integrated into flow models to assess the points where water vapor may condense out of the gas.

The tool can also be used to assess the point where high temperatures from pump or compressor output may have affected the pipe coating, as well as in settings to validate and improve SCADA and mass balance systems.

3. Pipe Wall Assessment and Inertial Mapping

During inspection, the SmartBall Pipe Wall Assessment (PWA) tool collects magnetic data that can provide a screening of the pipe wall for stress resulting from features like large cracks, large wall loss, dents and points of excessive loading.  The test can also complement hydrostatic testing, as it can survey the pipeline before and after hydro-tests to identify stress that is indicative of pressure reversals.

In addition, the SmartBall PWA tool can produce a girth weld and joint tally for the pipeline, as well as can confirm locations of bends and general geometry of the pipeline.

Helping operators make better decisions

Admittedly, SmartBall is not designed to compete with high resolution technologies like Magnetic Flux Leakage (MFL), which can provide detailed wall loss data.

What SmartBall can do is complement other integrity tools by providing additional data sets to ensure pipeline integrity. In a single deployment, it can detect anomalies associated with pinhole leaks and stress that doesn’t necessarily involve wall loss; e.g. geotechnical strains.  It can also detect change in pressure and temperatures.

Ultimately, the SmartBall tool can help capture enough data to confirm the integrity of the pipe and give operators enough microscopic knowledge to make better, informed, risk-based decisions on the health of their pipelines.

At Singapore International Water Week 2016, one of Pure`s licencees presented a poster on two acoustic-based technologies (tethered Sahara® and free-swimming SmartBall®) used to locate 674 leaks on large-diameter trunk mains operated by this Malaysia water operator.

Conducted over four months, the in-line inspection and resulting repairs has saved total of 46.7 million liters of water daily. The pipe diameters ranged from 300mm to 2,200mm.

 

SmartBall in-line leak inspection platform

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and ability to inspect long distances in one deployment. The free-swimming, acoustic-based SmartBall assembly is inserted into the flow of a pipeline, traverses the pipeline, and is captured and extracted at a point downstream.

Sahara in-line leak detection platform

The tethered Sahara tool includes an acoustic sensor to perform leak and gas pocket detection, a high-resolution video camera to assess internal pipe conditions, and an electromagnetic sensor to identify stress in the pipe wall. Because the parachute-like tool is drawn by product flow and is tethered to a data acquisition unit on the surface, it gives the operator close control to confirm suspected leaks, gas pockets and other pipeline anomalies.

 

Georgia Road Sign

Unlike many large, well-funded municipalities, smaller mid-sized communities often lack the financial resources to conduct proactive inspections on their buried infrastructure. Generally it’s a common situation prevalent across much of the United States.

For this reason, when several medium-sized Georgia communities were provided state funding for an inspection and condition assessment on critical sections of their water pipelines, they jumped at the opportunity to have actionable information about their actual pipeline condition.

A baseline condition inspection helps operators make defensible decisions

The Georgia Environmental Finance Authority (GEFA) facilitates programs that conserve and protect Georgia’s energy, land and water resources. In this instance, GEFA provided technical assistance funding for seven mid-sized communities to perform condition assessment on large diameter lines, which for these communities, ranged from 8-inch polyvinyl chloride (PVC) to 24-inch ductile iron pipes.

Pure Technologies was retained to perform condition assessment work for seven (7) Georgia communities, which included Marietta Board of Lights and Water, Paulding County, Haralson County, City of Dublin, City of Valdosta, Spalding County, and Coweta County—whose populations ranged from 10,000 to 100,000.

For the most part, Pure performed a SmartBall® leak and gas pocket inspection and Transient Pressure Monitoring with Fatigue Analysis on the potable water pipelines for the subject communities.

In addition, Pure was also retained to deploy a SmartBall® Pipe Wall Assessment (PWA) on the ductile iron mains for the City of Valdosta Utilities Department and the Marietta Board of Lights and Water.

PWA data

SmartBall PWA technology is used to evaluate metallic pipelines by detecting and measuring the changing levels of the magnetic field, which is related to the stress in the pipe wall. As a screening tool, PWA technology provides an indication of pipe sections exhibiting higher levels of stress, which can be used as a first stage of pipeline condition assessment to help make informed decisions on higher resolution investigations, inspection, data collection and subsequent management or rehabilitation.

SmartBall tool chosen for its ease of use and sensitivity to small leaks

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and ability to inspect long distances in one deployment. The free-swimming, acoustic-based SmartBall tool is inserted into the flow of a pipeline, traverses the pipeline, and is captured and extracted at a point downstream.

SmartBall inside a pipe with a net

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

Deploying the SmartBall tool allowed each inspection to take place while the mains remained in service, a benefit much appreciated by the communities.

“This was an excellent opportunity to offer mid-sized communities in Georgia with a non-destructive internal inspection of critical pipes within areas where traditional methods may not able to collect this important information. Pure provided very professional service to work with the Utilities and help develop a specific plan to acquire this valuable data.”

Larry Lewison, NRW Analyst, Consultant

Inspection not without its challenges

In general, for most of these smaller communities, condition assessment was a novel concept, which meant lots of communication between Pure and the utilities. Mid-sized utilities, understandably, are often hamstrung by a lack of as-built drawings, geographic information systems (GIS) or other connection and appurtenances information on their pipeline network.

In the end, based on Pure’s many years of inline inspection experience and expertise, obstacles were overcome and the overall inspection program was a positive learning experience for all.

Results from cumulative 11.7 miles of inspection

Immediately after each inspection, the data was downloaded from the SmartBall tool, verified for quality and sent to Pure Technologies for review by the analysis team.

Based on the acoustic results of all the SmartBall inspections, three (3) true leaks and zero (0) acoustic anomalies characteristic of gas pockets were found on a cumulative distance of 11.73 miles of pipe inspected. For the city of Valdosta, which included a PWA inspection, Pure identified 30 specific pipes as having anomalies indicative of stress. For the Marietta Board of Lights and Water, Pure detected 61 stress anomalies along the pipe wall. This indicates a 22 percent anomaly rate, which is average compared to historical data on similar pipelines.

In addition, Pure also performed fatigue analysis for all PVC pipes, and no immediate concerns were noted.

The results indicate that the assessed mains are generally in serviceable condition, and gave the Georgia communities confidence in the overall health their systems, with no need for immediate rehabilitation, except for the three leaks that warranted attention. This process allows the communities to develop a sustainable long-term strategy for managing their critical buried assets.

Insertion and extraction sites

Utilities have limited asset management funding at their disposal and yet waiting for failures to happen before repairing or replacing critical water mains is simply not a cost-effective option.

Cities need a working water infrastructure. It’s that simple. The solution, though, has tended to be a lot more complicated. The majority of urban water infrastructures are old and reaching the end of their usage expectancy. In addition, most are buried deep beneath the very cities they service and system-wide pipeline replacement is far too costly. Yet, if those large-diameter pressurized pipelines unexpectedly fail, the consequences can be catastrophic, to the city and the people living there. It can also shake the public’s confidence in the utility, harming its reputation in the process.

The fact is, not all old pipe is bad pipe. The Water Research Foundation Report found that age is not a primary factor for pipe failure. Many buried pipes, well over 100 years old, can still be considered in “like new” condition. Through extensive research and data from more than 14,000 milesof pressure pipeline inspection, we have found that less than 1% of pipes are damaged enough to need immediate repair. And that’s good news for cash-strapped, resource-short pipeline operators.

Unfortunately, there is no “one technology fits all” solution to this problem, which is why the choice of assessment tools is critical. The smartest choice is to deploy different but complimentary technologies that can collect the robust condition data required to evaluate which pipes need repair or replacement and which should be left alone. This pipe-by-pipe approach helps utilities make informed decisions based on assessment results, which in turn can reduce capital costs by as much as 90 percent.

Pure Technologies’ Assess and Address® approach is not only logical, scalable and cost effective, it also provides the highest return on investment.

Beginning with Pure’s risk-based assessment method followed by the deployment of complimentary technologies – like SoundPrint® – we work together with utilities to help facilitate pro-active, cost effective renewal and enduring pipeline management strategies that help keep our cities up and running for years to come.

Hanging rock with a sheep above

Don’t Get Stuck Between a Rock and a Hard Place

City of Ottawa Skyline

When your inspection task is to survey a critical pipeline for leaks, nothing is more satisfying than trusting your technology to predict the leak location and then standing by as the client excavates the area to find a flow of water within one meter of exactly where you said it would be.

The above-described “leak-where-predicted” recently happened with the City of Ottawa, when Pure Technologies (Pure) deployed its SmartBall® inspection platform to locate leaks along a critical transmission main, as part of a long-term condition assessment program for the municipality. Over the past five years, Pure has used its suite of platform tools, including Sahara®PipeDiver®, and PureRobotics®, as well as the free-swimming SmartBall device, for deployment on the City’s ongoing Drinking Water Transmission Main Condition Assessment Program.

Transmission main comprised of 1220mm (48-inch) lined cylinder pipe

The City’s potable water distribution system consists of 3,728 km of both local water mains and large-diameter transmission mains that move large volumes of water throughout the capital. The City has approximately 230 kms of transmission mains ranging in diameter from 600mm to 1980mm, (24-inch to 78-inch) subdivided into 96 segments for the purpose of a risk-based prioritization.

For the subject project, the City of Ottawa retained the services of Pure to perform a SmartBall tool inspection to identify and locate leaks and pockets of trapped gas along the Baseline Road Water Transmission Main, a high priority pipeline. The 1220mm (48-inch) diameter pipeline is comprised of Lined Cylinder Pipe (LCP) mostly constructed in the 1970s.

Pipe leaking

SmartBall tool chosen for its ease of use and sensitivity to small leaks

The SmartBall tool was chosen as an inspection platform for its sensitivity to small leaks, minimal pipeline modifications required for insertion and extraction and ability to inspect long distances in one deployment. The free-swimming, acoustic-based SmartBall assembly is inserted into the flow of a pipeline, traverses the pipeline, and is captured and extracted at a point downstream.

SmartBall extraction process

During inspection, the SmartBall tool’s location is tracked at known points along the alignment to correlate the inspection data with specific locations. As the SmartBall tool approaches a leak, the acoustic signal will increase and crescendo at the point when the tool passes the leak.

For the City of Ottawa project, five (5) surface-mounted acoustic sensors were placed along pipeline to track the SmartBall tool during the inspection. SmartBall receivers were connected to the sensors on the pipeline at the locations indicated to track the tool during inspection.

The SmartBall device was inserted into the pipeline through a 100mm drain near a hospital. Acoustic and sensor data was collected and recorded as the SmartBall tool traversed the pipeline for more than three kilometers. The SmartBall was then extracted from a reservoir using a Remotely Operated Underwater Vehicle and data was evaluated to identify acoustic anomalies associated with leaks and pockets of trapped gas.

Verification with ground microphones turned up unexpected results

From the survey results, Pure detected one (1) acoustic anomaly characteristic of a leak and zero (0) anomalies consistent with pockets of trapped gas.

Although Pure was confident in the SmartBall leak detection data, sometimes it’s worth a try to verify an anomaly with a complimentary technology. In this instance, ground microphones, regarded as a conventional a leak detection tool, were deployed to try and detect leak sounds. Although the suspect area was marked, neither Pure nor the client could pick up leak-related sounds from the ground microphone.

Even though the leak was not picked up by the ground microphone, Pure was confident that the acoustic signature from the SmartBall was caused by a leak, based on more than 15 years of experience identifying leaks. That confidence and experience proved right, and when the suspected area was excavated, the leak was located within a meter of where data analyst calculated the leak to be.

The results gave the City of Ottawa actionable data regarding the condition of their pipeline, and the City was able to fix the leak reducing non-revenue water loss and any potentially costly damage caused by the leak. It’s a great example of a proactive utility taking efforts to improve the reliability of its services.

SmartBall extracted by Pure technicians

*Published in World Pipelines Magazine

The oil and gas pipeline industry has been under close scrutiny for a long time. It leads the way as one of the most regulated industries in the world, and for good reason.  With so many safety-related, social and environmental factors at stake, comprehensive regulation ensures rigorous standards for the design, construction, operation and maintenance of O&G pipeline systems.

Global economics and political activism also play a role in shaping today’s conversation about pipelines. In North America, public debates about the Keystone XL Pipeline have dominated much of the recent news, compelling operators to vigorously participate in the discussion and advocate their integrity management programs. Although Keystone has been put on hold, social capital can assist in getting projects of this magnitude on the radar again.

Through it all, much of the dialogue has focused on the industry’s commitment to protecting communities and the environment from risk by means of rigorous pipeline integrity management programs. As a result, the requirement for increased pipeline safety drives innovative research into improving the sensitivity and reliability of inline inspection (ILI) tools.

Most operators already deploy trusted inline technologies that detect structural deterioration and help maintain pipeline integrity. However, with pressure mounting from stricter regulation, increased operational costs, commodity price-driven budgetary pressure, and often limited available resources, operators face an increasing number of challenges, including vigilance from highly engaged consumer groups.

Although the pressure to perform is greater than ever, operators are responding appropriately with greater confidence in modern technologies to assist in the operation and monitoring of their pipeline systems.

Better ILI tools instill better confidence in containment

To have confidence in the pipeline, operators must have confidence in the capabilities of ILI tools to detect small anomalies that could lead to potential failures.  They must also trust the reliability and interpretation of the data, knowing with as much certainly as possible that the depth, size and location of the pipe wall anomaly is correct.

Overall the news is good. Between 2002 and 2013, Canadian Energy Pipeline Association (CEPA) member companies were able to transport oil and natural gas with a 99.999 percent safety record. While that statistic sounds impressive, headline-grabbing pipeline incidents do occur, (in 2014 there were 122 natural gas and liquid releases) and when that happens, the repercussions can undo years of containment management trust and goodwill.

While the oil and gas industry boasts a remarkable safety record, a reliance on conventional tools limit the near perfect record.  As much as the technologies have been refined, regulators have noted that inline inspections don’t pick up all defects, and expedient follow-through often depends on the people analyzing the data and planning repairs, a process that can take months.

“Despite their sophistication, the detection capabilities of inline inspection tools have limitations,” the US National Transportation Safety Board noted in its report on the 3.3-million-liter 2010 spill in Michigan.

Limitations of conventional ILI inline inspection technologies

The oil and gas pipeline industry has access to an extensive toolbox of technologies for robust integrity programs. Some tools address cracks or corrosion issues, while other tools focus on stress, pressure and product containment. Cost, resolution, reliability, data analysis speed – each technology has its own strengths and limitations, with no silver bullet as the single solution for collecting pipeline condition information.

For example, there is a strongly-held belief in hydrostatic testing as a reliable method to test a pipeline’s integrity. One of the earliest inspection techniques, hydrostatic testing determines if a pipeline can hold its operating pressure. A form of destructive testing, hydrostatic inspection involves purging the product, flooding the line with water, pressurizing it to a predetermined level and maintaining the pressure for a period. Based on the results, detected anomalies in pressure, volume and density can be a precursor to leaks.

Critics however, argue and have quite effectively demonstrated that the hydrostatic tests lack the ability to monitor ongoing corrosion or cracking and that the high pressure environment can exacerbate previously small defects, increasing risk of future rupture.

Smart pigs for detecting large cracks and corrosion

Unlike hydrostatic testing, which is often conducted on pipelines for acceptance testing or for pipelines recently rehabilitated, pigging is the more commonly accepted method of testing pipeline integrity.

While newer “smart” pigs have an excellent reputation for accuracy, their efficacy is often limited to detecting corrosion and cracking that exceeds the threshold for detection of the technology.  Small corrosion pits and cracks, especially cracks grouped in a colony, can pose a challenge to most conventional ILI pigging devices.

The various ILI technologies are sensitive to axial or circumferential defects, and each has limitation for minimum aspect ratios or cross sectional wall loss area before the ILI tool can report the anomaly.  It is also possible to have cracks and wall loss pits that are in close proximity to girth welds, long seams, and other features in the pipe, which can mask the defect, preventing the ILI tool from properly identifying and sizing.  As a result, it is possible to have leaking cracks and corrosion pits that are too small to be sized and reported from conventional ILI.

Not all lines are piggable

Some pipes are more suitable for pigging than others. While most oil and gas transmission lines were built in long straight sections suitable for pig runs, sections with small diameter pipe and small bend radius pipe configurations can limit many ILI tools.  Lines with expansion loops and miter bends, and in the case of natural gas lines, those with reduced port valves, are factors that can prohibit or restrict the traversing of inline tools.

Mass balance measurement and other leak detection tools

To make up for the limitations of conventional ILI technologies, operators often deploy measurement methods and leak detection technologies to complement their integrity programs.

Mass balance is a means of detecting leaks by measuring the mass of product entering the pipeline compared to the mass exiting the pipeline. The limitation for detecting small leaks is the sensitivity of the mass meters being used (2-4% accuracy for conventional orifice meters and 0.25% for turbine meters), and the fact that the product temperature and pressure changes as it moves through the pipeline.

While mass balance is a means to determine leaks, it is also recognized that making actual measurement of mass from volume (through a meter) at different temperature and pressure going in versus coming out of the pipeline, in real time, is difficult, and not very precise or sensitive to small leaks.

As a result, a leak has to release more product than the total tolerance of the mass balance system before a positive leak/release event is alarmed.

Acoustic leak detection

Minute cracks are often preliminary indicators of potential small leaks that produce acoustic emissions at levels often unrecognizable over background noise.

Acoustic leak detection can be conducted with geophones/hydrophones, comparators and acoustic fiber optic techniques, and each of these acoustic tools is subject to different background noise limitations to determine leak detection thresholds.  Not only can these tools have limitations to prevent small leak detection, the expense from installing permanent acoustic systems may reduce the practicality of these technologies.

Emerging technologies on the horizon

To complement hydrostatic testing, conventional pigging tools, and leak detection technologies, the oil and gas industry is evaluating a growing number of emerging external confirmation of containment technologies. These include vapour-sensor systems, hydrocarbon-sensing cables that change in the presence of hydrocarbons, internal pressure wave based tools and fibre-optic based systems that detect temperature changes and acoustic signals associated with leaks.

While these technologies offer hope for more precise surveys, they have yet to be universally accepted or proven. Many are still under development and often require economically impractical installation requirements.

However, there is an innovative, multi-sensor ILI platform that has been used in integrity management programs since 2006, gaining the attention of major pipeline players who have tested the platform, which has now been used on over 25,000 kilometers of pipeline in total.

Introducing SmartBall® technology for Oil & Gas pipelines

To provide a realistic snapshot of a pipe’s condition, many proactive operators are deploying SmartBall technology,  a free-swimming multi-sensor tool for long inspections of piggable and difficult to pig liquid and gas pipelines 4 inches and larger. This advantage makes the ball-shaped tool an excellent choice for traversing not just standard diameter pipes, but for smaller diameter liquid lines and for gas pipelines with loops and frequent sharp bends and heavy wall fittings.

During an inspection, the SmartBall sensors collect acoustic, pressure, temperature, magnetic and inertial data from inside the pipeline.

Primary applications for the SmartBall tool

SmartBall surveys can be conducted independently, at regular intervals, as part of a routine pipeline integrity management program, or as a value-add to inspection programs along with hydro-testing, ILI, or direct assessment.

The tool is launched and retrieved at existing pig traps and is tracked using proprietary acoustic receivers and/or Armadillo pig tracking boxes (AGMs). The location data from acoustic receivers and tracking boxes is used during data analysis to locate any anomalies.

SmartBall technology has three primary applications, and the multi-sensor tool can provide a variety of pipeline data.

1. Confirmation of Containment

Regular confirmation of containment surveys are an important part of integrity management as leaks are often a preliminary indicator of pipe failure.

Unlike conventional leak detection systems, confirmation of containment with SmartBall supplements these systems. The SmartBall tool directly passes leaks, and is therefore capable of detecting losses as small as 150 mL/min, which can be several orders of magnitude more sensitive than conventional methods.

SmartBall surveys can also complement regular ILI surveys by addressing potential pinhole anomalies that have aspect ratios below the reporting threshold of ILI systems.

2. Pressure and Temperature profiles

As the SmartBall is rolling and not sealing against the pipe ID, as conventional pigs do, the tool can also record precise pressure and temperature profiles. The SmartBall platform can be deployed in gas pipelines, where pressure and temperature profiles can be integrated into flow models to assess the points where water vapor may condense out of the gas.

The tool can also be used to assess the point where high temperatures from pump or compressor output may have affected the pipe coating, as well as in settings to validate and improve SCADA and mass balance systems.

3. Pipe Wall Assessment and Inertial Mapping

During inspection, the SmartBall Pipe Wall Assessment (PWA) tool collects magnetic data that can provide a screening of the pipe wall for stress resulting from features like large cracks, large wall loss, dents and points of excessive loading.  The test can also complement hydrostatic testing, as it can survey the pipeline before and after hydro-tests to identify stress that is indicative of pressure reversals.

In addition, the SmartBall PWA tool can produce a girth weld and joint tally for the pipeline, as well as can confirm locations of bends and general geometry of the pipeline.

Helping operators make better decisions

Admittedly, SmartBall is not designed to compete with high resolution technologies like Magnetic Flux Leakage (MFL), which can provide detailed wall loss data.

What SmartBall can do is complement other integrity tools by providing additional data sets to ensure pipeline integrity. In a single deployment, it can detect anomalies associated with pinhole leaks and stress that doesn’t necessarily involve wall loss; e.g. geotechnical strains.  It can also detect change in pressure and temperatures.

Ultimately, the SmartBall tool can help capture enough data to confirm the integrity of the pipe and give operators enough microscopic knowledge to make better, informed, risk-based decisions on the health of their pipelines.

Oil and gas pipeline owners conduct routine inspections of their pipelines using inline inspection (ILI) tools known as pigs. ILI pigs can identify defects within the pipe wall and need to be tracked when they are travelling through a pipeline.

Pig tracking can be expensive (as much as 25% of the ILI budget) and costs can vary from vendor-to-vendor, especially when you factor in the different methods used to track pigs, such as remote tracking and conventional tracking. In order to ensure that tracking budgets are used efficiently and defensibly, each ILI run should be thoughtfully planned to determine the most appropriate tracking method.

Per Mile Cost Fluctuations

Drawing of a worker

Even after thorough planning, cost estimates can vary from vendor-to-vendor, raising questions about per mile cost fluctuations. To reduce the per mile cost of tracking, service providers often reduce the quality of tracking per mile. In traditional tracking, sending out lesser-trained technicians at cheaper rates, enacting only minimum safety measurements and using only one tracking sensor to identify pig passages are all ways that vendors can reduce per mile tracking costs.

An important consideration for pipeline owners and ILI vendors is determining how much risk they are willing to take when tracking their ILI programs. In most cases reducing the per mile costs by 10 to 15 percent is not worth the risk of using low-quality tracking techniques. A single missed or lost pig can easily negate the savings from using the lowest-cost provider.

In most cases, using remote tracking can decrease both the risk and cost of an ILI run. Remote tracking requires fewer staff and equipment resources than conventional tracking and is much safer.

To learn more about remote tracking and its benefits, download PureHM’s pig tracking white paper.

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City of Milwaukee Skyline

Milwaukee is a water hub, and not just because of its location along the shores of Lake Michigan, which holds 4.3 percent of the world’s supply of fresh drinking water. The City also boasts of global leadership in water technology, having won a U.S. Water Prize for innovative watershed-based approaches toward water sustainability.

The City takes a proactive approach to water management initiatives, as evidenced in the recent condition assessment of the Franklin-Muskego Force Main. Ownership of the pipeline is shared between the City of Muskego and the Milwaukee Metropolitan Sewerage District (MMSD), the government agency that provides water management services for about 1.1 million people in 28 communities in the Greater Milwaukee Area.

Metallic valves

MMSD and Muskego request detailed structural assessment on metallic force main

In 2015, Pure Technologies (Pure) was contracted to perform a detailed condition assessment of the approximately 25-year old pipeline. The purpose of the assessment was to identify the structural condition of the metallic force main, and included pressure monitoring, a SmartBall® leak and gas pocket detection survey, a PipeDiver® electromagnetic inspection, and structural evaluations of the pipeline.

Notably, the latest investigation used electromagnetic technology delivered on the 24-sensor mini PipeDiver platform to validate inspections conducted the previous year along the same lines.

Ductile iron pipe is a challenging material to assess

The Franklin-Muskego Force Main carries wastewater along approximately 1.6 miles of 24-inch and 1.3 miles of 30-inch ductile iron pipe (DIP). A small section of 20-inch DIP force main was also included in the survey.

One of the challenges in assessing DIP is determining if the pipe has undergone any loss of wall thickness due to internal or external corrosion, which are the primary causes of failure. DIP in water service with a cement mortar lining generally has fewer internal corrosion failure rates, unless damaged during handling and installation, or later as a result of 3rd party damage.

This is not the case when DIP is used in a force main, where internal corrosion is the primary cause of failure. Gas pockets are of significant concern as concentrations of hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Gravity mains vs pressurized mains

In a force main, identifying internal areas with potential corrosion is challenging, as traditional gravity pipeline inspection techniques are often not applicable to in-service pressurized pipelines.

One method for assessing gas pockets is to locate air release valves (ARVs) or other high points along the alignment and provide pipe wall assessment in those areas. While this is a valid method for locating potential gas pocket locations, additional gas pockets may occur due to differential settlement, improper installation or non-functioning ARVs.

Therefore, these desktop surveys may not identify and locate all gas pockets along a pipeline, which is why Pure recommends other more precise survey methods.

SmartBall with case and insertion tools

SmartBall inspection summary

In June 2014 and October 2015 Pure performed a SmartBall leak and gas pocket detection survey of the Franklin-Muskego Force Main. Acoustic and sensor data was collected and recorded as the free-flowing SmartBall device traversed the pipeline.

During the 2014 survey, Pure detected zero (0) anomalies characteristic of leaks and one (1) anomaly that characterized a fully developed gas pocket.  During the 2015 survey, the SmartBall tool detected zero (0) anomalies characteristic of leaks and four (4) acoustic anomalies characteristic of fully developed gas pockets on the force main.

PipeDiver tool. insertion

24-sensor PipeDiver electromagnetic inspection

In 2014 Pure conducted a PipeDiver electromagnetic inspection, followed by a re-inspection in 2015, utilizing the new, 24-sensor electromagnetic PipeDiver tool. The technology ascertains a magnetic signature for each pipe section to identify anomalies that are produced by areas of corrosion or reduced wall thickness.

During the 2015 electromagnetic inspection using the mini PipeDiver, 13 pipes were found to have a total of 16 electromagnetic anomalies consistent with localized wall loss.

The electromagnetic inspection conducted in the 2015 inspection used an enhanced exciter coil allowing the electromagnetic field to return a more pronounced response. In addition to the enhanced exciter coil, the tool used in the 2015 inspection had a total of 24 receiving sensors, improving the ability of the tool to identify defects.

Confident conclusions

The results of the condition assessment indicate that the Franklin-Muskego Force Main is generally in serviceable condition, which was confirmed after an excavated pipe established a true baseline condition.

While the assessment recognized several areas with an increased likelihood of failure, overall the data was good, and coupled with Pure’s engineering recommendations, gave all stakeholders confidence in the health of pipeline for the near foreseeable future.

City of Belmont Skyline

To help budget over the next 20 years, the City of Belmont (City) wanted to proactively understand and assess their force mains through a comprehensive condition assessment. Located in the San Francisco Bay area, Belmont serves 26,000 residents and maintains more than 90 miles of sewer mains comprising of 85 miles of gravity mains and 5 miles of force mains, of varying size and material.

To address its goal, the City contracted Pure Technologies (Pure) to deploy a wide range of both proprietary and third-party technologies and techniques to achieve a holistic assessment. The risk associated with a failure was significant, owing to a lack of redundancy, difficulty and cost of bypassing flow and potential for severe consequences to public health and the environment.

Pure provided inspection and condition assessment services on eight of the City’s force mains. The project scope included GAP analysis, condition assessmentengineering analysis, and necessary repair or replacement recommendations to establish a long-term management plan for Belmont’s force main inventory.

Variety of solutions and technologies used to assess inventory

A number of solutions and technologies were used to assess Belmont’s force mains. Phase one involved a GAP analysis, performed by interviewing operations staff and reviewing historic information, GIS maps, and drawings.

Phase two included an assessment of the eight force mains through the use of various technologies, including SmartBall® leak and gas pocket detection, SmartBall Pipe Wall Assessment (PWA), soil corrosion survey, hydrogen sulfide monitoring, transient pressure monitoring, and hydraulic evaluation.

SmartBall with extraction tool and controls

SmartBall leak detection is a free-flowing tool used to locate leaks and gas pockets in pressurized pipelines. The tool is equipped with a highly sensitive acoustic sensor that is able to locate “pinhole” sized leaks. Pipeline leaks are of concern for force mains as these emit illegal discharges to the environment and are often found to be a precursor of major failures. In metallic pipes, gas pockets are of significant concern, as hydrogen sulfide gas within wastewater may be subsequently converted to sulfuric acid by bacteria in the slime layer on the pipe wall.  This may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Pipe wall assessment (PWA) is a screening technology for assessing the condition of metallic pipelines by identifying pipe sections with increased levels of stress. SmartBall gas pocket and leak detection services were used for the 8-12-inch diameter mains.

Transient pressure monitoring and hydraulic evaluation used on the smaller mains

Transient pressure monitoring and hydraulic evaluation was used to evaluate the smaller 6-inch force mains. Hydraulic pressure transients occur in pipelines when steady-state-conditions of the system change due to pressure or flow disturbances. It is important to conduct transient pressure monitoring and hydraulic evaluation because damage from pressure transients can include cracking of mortar coating or lining, crack propagation, movement at joints, and structural fatigue.

During the condition assessment, Pure evaluated the likelihood and consequence of failure criteria and developed a scoring system, placing each force main in one of three categories: low risk, moderate risk, or high risk.

Satellite image with location map

For phase three, Pure conducted a life cycle and financial analysis, outlining the potential life and replacement/repair costs for each force main. By comparing results identified in each assessment phase, the City of Belmont can now move forward and create both a short-term and long-term rehabilitation plan.

“Through innovative technology, comprehensive data gathering and analysis, Pure Technologies helped us to assess condition of our large force mains within budget constraints, to help us plan our future capital improvement program…”

Each main evaluated with an overall risk rating

The GAP analysis included a review of all the information given to Pure at the beginning of the project and included historic information, GIS, and some drawings. During this phase, many of the parameters such as pipe length and material were found to differ from what was originally thought through the process of internal inspections and external excavations.

Pure conducted the SmartBall leak and gas pocket detection survey on four force mains and found 21 unique anomalies. The SmartBall PWA discovered seven indications of stress on the two metallic pipelines.  Hydraulic analysis of all eight force mains revealed that several force mains have a nominal increased potential for failure due to significant pressure swings and a large quantity of pumping cycles. Hydrogen sulfide monitoring was performed on six force mains to quantify the potential for internal corrosion caused by hydrogen gas.

Once all tests were completed, each force main was evaluated by its likelihood of failure and consequence of failure, and then given an overall risk rating.

Assessment includes life cycle and financial analysis

By determining overall risk for each force main, Pure was able to complete a life cycle and financial analysis and provide Belmont with the best data available to make long-term decisions on managing their assets. Each force main was given an estimate of its remaining life as well as a financial comparison of different management option costs. The financial comparison took capital replacement costs into account with Pure’s Assess & Address™ approach in both the best case and worst case scenarios. In both instances, the management options showed costs significantly lower than a full capital replacement option.

Using both the data and short and long-term recommendations provided by Pure, Belmont is now fully equipped to make the best possible decision and budget accordingly over the next 20 years, while continuing to address and mitigate risk.

Traditional methods of wastewater condition assessment focuses almost exclusively on the gravity system and valve
actuation, using tools such as smoke testing, CCTV, and zoom cameras. While effective on gravity mains and valves,
these methods are not applicable in force mains.

Inspecting force mains is more challenging due to lack of redundancy, lack of access points, cost, technology limitations, while the consequence of force main failures can be significant financially, environmentally and socially.

A successful wastewater asset management program uses a holistic approach which prioritizes the entire system, collects data through condition assessment and provides analyzed reports in order to develop a targeted, informed action plan for long-term sustainability of a collection sewer system.

Pigging is the most common form of inline inspection used by oil and gas pipeline owners. There are two ways of tracking a pig through a pipeline; legacy tracking and remote tracking. Historically, pigs have been tracked using legacy methods, where a field technician would follow the pig from site to site to confirm its location and ensure the pig reaches the trap.

Remote tracking combines leading-edge above ground markers (AGMs) and Remote Tracking Units (RTU’s) that are pre-deployed before an ILI run and are used to track the pig from a central location. As a pig approaches a tracking site, the remote unit is activated to track the tool, and does not require a field technician to be on site.

It is a common misconception that remote tracking is more expensive than traditional legacy tracking methods due to the presence of advanced technology; however, remote tracking is often significantly cheaper than legacy tracking.

When to use remote tracking

Moon, Earth and satellite

Remote tracking is less expensive than legacy tracking when there are multiple pig runs or accessibility issues with tracking locations. Using remote tracking, each site only needs to be accessed twice – for equipment deployment and retrieval. Using legacy methods for a multi-pig run would require trackers to access each site multiple times, which can significantly increase costs.

While this seems insignificant, reducing the number of field trackers, trucks, and subsistence charges can drastically reduce a project’s cost. In addition, remote tracking helps to normalize project costs, as unexpected delays or standby days don’t result in additional costs for the pipeline owner.

Before any ILI run, pipeline owners should evaluate all the potential risks and costs to determine the best method of tracking the pig. If multiple pig runs need to be conducted, tracking locations are inaccessible, or if the run will span over a long distance, remote tracking can save pipeline owners upwards of 50 percent compared to traditional legacy tracking.

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Louisville Water Tower and Pumping Station house the WaterWorks Museum

To many history buffs, “the prettiest ornamental water tower and pumping station” in the U.S. belongs to Louisville Water Company (Louisville Water). In 1860, the water company, which today provides water to more than 850,000 people in Louisville, Kentucky and surrounding communities, built its first water tower and pumping station in the form of a Greek temple complex.

Today, the Louisville Water Tower and Pumping Station house the WaterWorks Museum, and Louisville Water continues to make history using modern technology from Pure Technologies to assess its extensive water network.

Focused on pipes with the potential to cause the most damage

Following a water main break in 2009 that resulted in the loss of 15 million gallons of treated water, Louisville Water began a Transmission Assessment Program, first deploying Pure’s PipeDiver® technology to conduct a practical and cost-effective way to inspect transmission mains. Over the succeeding years, this program has evolved to include with other assessment technologies from Pure’s toolbox.

Transmission Assessment Program utilizes a variety of assessment tools

In the summer of 2015, Louisville Water deployed PureRobotics to assess 3.41 miles of 24 to 30-inch transmission mains in its network. With over 4,100 miles of pipeline to maintain (200 miles of it transmission main), Louisville Water focused its condition assessment on its transmission main system – pipes that would cause the greatest amount of damage in the case of failure. The loss of non-revenue water, either in continuing small amounts or from a catastrophic failure, can result in massive costs to a water utility.

By prioritizing the risk levels associated with their transmission main system, Louisville Water has created an ongoing inspection program to keep a watchful eye on the health of their pipelines. The program utilizes a number of Pure Technologies assessment tools to find active leaks as well as potential future threats.

In May of 2015, PureRobotics was deployed on the Cross County Header, Ray Lane Easement pipeline, and Bardstown Road pipelines. For Louisville Water, PureRobotics used CCTV to provide a comprehensive high-definition visual inspection. The robotic crawler was also outfitted with specialized tools to conduct an electromagnetic assessment on the condition of the pipeline and inertial measurement unit (IMU) for a GIS component.

The Inertial Measurement Unit (IMU) deployed with PureRobotics uses a series of Fiber Optic Gyroscopes (FOGs) and accelerometers to track depth, lateral and horizontal movements from a known GPS reference point. The output is a GIS spatial map of the pipeline which depicts elevation changes as well as notable features of interest encountered during the inspection.

PureEM electromagnetic assessment detects anomalous regions in the pipe cylinder and prestressed wires. This data is correlated with odometer readings from the PureRobotics umbilical tether as well as HD recorded CCTV and IMU to attempt to locate areas of distress in the pipeline.

Anomalous pipe

One of the 11 anomalous pipes excavated.

Due to its mobility, PureRobotics is ideal for multiple isolated inspection runs where a quick setup and breakdown can improve efficiency.  The transporter can be deployed from a number of access styles including valves, open flange, and open pipe. In the case of the Louisville Water inspection, the PureRobotics system was inserted into the pipeline via newly installed vertical gate valves and existing boiler plate style hatches. Inspection lengths varied in length from 70 feet to beyond 2,000 feet.

Staff deploying PureRobotics

Louisville Water deployed PureRobotics to assess its transmission mains.

Results gave Louisville Water the confidence to prioritize its rehabilitation program

High definition CCTV inspection results showed a number of longitudinal cracks consistent with overloading. These types of mortar cracks may eventually lead to corrosion of the steel cylinder or prestressing wire and eventually a failure of the pipe.

One pipe section in the Ray Lane Easement pipeline was found to display anomalous electromagnetic signals showing a significant number of broken prestressing wire wrap breaks as well as cylinder wall loss. This was correlated with visual data, showing spalling and exposed steel at the invert of the pipe.

Visual assessment also showed a number of pipe sections with spalling. Electromagnetic assessment also found 11 pipes with anomalous signals not consistent with wire breaks. Investigation performed on one of these anomalous pipes showed a non-standard metal sleeve used in manufacturing. From this information, it was determined that the remaining 10 anomalous pipes could be left in service.

As one of the first utilities to deploy the third generation PureRobotics platform, Louisville Water now has defensible data to move forward with its ongoing rehabilitation program. For this historic water utility, modern technology really can help.

Kingston Pipe Material Map

Internal measurement map indicates various pipe materials detected during the conditon assessment of the Dalton Avenue force mains in Kingston.

The familiar adage, “never assume anything” certainly applies to the water and wastewater pipeline industry. The message was brought home to Utilities Kingston (UK) early this year when the utility was surprised to find unexpected pipe material on sections of pipe during a condition assessment on its Dalton Avenue (North End) Pump Station force mains.

Conducting a condition assessment on a pipeline can pose a particular challenge if the pipe material is unknown, as each pipe type exhibits specific characteristics that affect its structural integrity. Despite the challenge, UK managed to move forward thanks to assistance from Pure Technologies, bringing its inspection, risk assessment and engineering analysis services, along with its comprehensive suite of technologies to survey the pipeline for leaks, gas pockets and wire breaks.

Utilities Kingston is unique in Ontario, combining water, wastewater, gas and electrical services, and a broadband fibre optics provider under one company.  UK’s engineering and public works departments provide potable water and wastewater collection and treatment to 36,000 customers.  The utility owns and operates approximately 550 kilometres of water mains and 500 kilometres of sewer mains to service the local population of nearly 125,000.

With an average age of 35 years, each of their pipeline assets is entering a critical stage in its life-cycle.

The subject pipeline had experienced a failure and as a result, the utility was interested in exploring technologies to help them implement a comprehensive asset management program for their pipelines.

Condition assessment includes various screening technologies

UK retained Pure to perform a condition assessment inspection, consisting of a SmartBall® leak detection survey, a PipeDiver® electromagnetic inspection and a transient pressure monitoring on the Dalton Avenue Sewage Pump 450-millimeter and 600-millimeter force mains. The two sewage force mains are both approximately 1,550 meters long and follow a parallel route for approximately 1 kilometer.

The older of the two force mains is 450-mm (18-inch) in diameter, constructed of ductile iron, was built in the late 1950s, and had failed several times over its lifetime. The newer of the two force mains is 600-mm (24-inch) in diameter was an unspecified concrete pipe from the early 1960s. As the pipe material specifics were still unknown at the time of the inspection, Pure elected to conduct a free-swimming PipeDiver electromagnetic run to accommodate both possible types of pipe material – assumed by all to be bar wrapped pipe (BWP) and prestressed concrete cylinder pipe (PCCP). The PipeDiver inspection platform uses electromagnetic (EM) sensors to evaluate the existing condition of the pre-stressing wires. EM inspections collect a magnetic signature for each pipe section to identify anomalies that indicate zones of wire break damage. The presence of wire breaks in concrete pressure pipe is often a sign of impending failure.

Pure’s SmartBall tool was deployed on both pipes, checking for leaks and gas pockets.

PipeDiver on a street

Force main defects can vary from one pipe material to another

During a forensics exercise on the 600-mm force main using 12-detector PipeDiver technology, it was revealed that rather than BWP or PCCP, the actual pipe material included reinforced concrete pipe (RCP), which is not usually used in pressurized environments. Electromagnetic inspection of the RCP can only reveal anomalies on the circumferential cage and not the longitudinal bars.

Furthermore, the inspection identified 102 suspected metallic pipes, which were not identified as such in the original plan and profile drawings.

PipeDiver tool before insertion

Prepping the PipeDiver tool before insertion.

Pure first: metallic pipe condition assessment using mini PipeDiver tool in wastewater

Pure deployed its electromagnetic 24-detector mini PipeDiver tool to conduct a condition assessment of the 450-mm pipe. The purpose of the enhanced electromagnetic inspection is to locate and identify steel and ductile iron pipes that have indications of wall loss.

This marked the first condition assessment of metallic pipe using the 24-detector mini PipeDiver tool in wastewater, an exercise that confirmed the validity of the tool’s sensor technology.

Results lead to actionable information regarding rehabilitation

In the end, one (1) acoustic anomaly characteristic of transient gas on the 450-mm forcemain was identified during the analysis of the data collected during the SmartBall tool inspections.

No anomalies resembling leaks were identified within the 600-mm force main.

Of the 650 pipes inspected, a total of 55 pipes in the 450-mm Dalton Avenue Pump Station force main had electromagnetic anomalies characteristic of localized wall loss (DIP). These results represent a high percentage of distress along the length of the pipeline and indicate a high risk of failure.

The data collected from both the inspections and transit pressure monitoring gave Utilities Kingston a better understanding of their real, not assumed assets. The results were used to complete a structural evaluation of the force mains, and have provided UK with actionable information regarding any necessary repairs or rehabilitation.

Team Members of Pure and UK

Members of the Pure and UK team pose after a long day of inspection.

Lisboa Map

SIMAS Oeiras e Amadora distributes drinking water to 350,000 customers in the Lisbon region of Portugal.

Drinking water systems degrade over time, with the useful life of the pipe and component parts often lasting for decades. Of course, age is only part of the equation. The deterioration of any particular pipeline depends on a multitude of factors, including pipe material and class. To complicate matters, factors such as soil environment, chemical properties of the water, climate changes, and operational particulars can all contribute to weakened pipes.

All that said, when a suspected leak develops in a pressured main after only five years in operation, it’s important to locate and repair the leak and determine what operational, environmental or installation factors led to the failure.

That was the situation faced by Intermunicipal Service Oeiras and Amadora, a water management company responsible for the distribution of drinking water for the municipalities of Amadora and Oeiras in the Lisbon region of Portugal. SIMAS Oeiras e Amadora distributes water to more than 350,000 customers who have come to rely on the public company for their water services.

The F. Passarinhos-Atalaia duct is a pressurized pipeline that supplies water to one of eight reservoirs operated by SIMAS Oeiras e Amadora in the municipality of Amadora. Installed in 2007, the large 600 mm (24-inch) transmission main, made from ductile iron material, delivers drinking water to approximately 31 percent of Amadora’s residents, making it a critical part of the municipality’s buried infrastructure.

Pressure drop indicated possibility of critical leak

In 2012, SIMAS Oeiras e Amadora detected a noticeable pressure drop in the system, indicating the possibility of a critical leak, the predecessor of a potential rupture that could negatively impact the environment and significantly disrupt day-to-day life in the community.

When traditional leak detection methods—geophones and acoustic correlators­ were unable to detect the location and size of the leak, SIMAS Oeiras e Amadora called on its contractor to perform a leak detection survey using the innovative SmartBall tool from Pure Technologies (Pure).  Because of the criticality of the line, the survey was conducted while the pipeline remained in operation.

Since 2007 utilities all over the world have been using Pure’s SmartBall pipeline inspection technology to save millions of dollars in water loss and prevented water main breaks.

SmartBall inside a pipe

Pure’s SmartBall tool can be launched while the main remains in operation.

SmartBall tool launched without disrupting service

Pure’s patented SmartBall tool is an aluminum-core, foam-shell ball packed with several different sensors that can be launched into a water main without any disruption to client service.

Unlike traditional external listening tools that have limited success on large diameter pipes, SmartBall is the industry’s only free-flowing multi-sensor technology that provides the highest degree of accuracy, since as the ball rolls, it can inspect every inch of a water main to detect potential problems such as leaks and gas pockets. Its highly sensitive acoustic sensors can locate ‘pinhole’ leaks and gas pockets within a location accuracy of 1.8 meters.

The SmartBall was inserted into the pipeline through a 6” gate valve and the journey took two hours and 49 minutes. One small leak was detected, 863 meters from the insertion site. This leak was repaired and allowed SIMAS Oeiras e Amadora to recover costs associated the loss of non-revenue water, had it remained undetected.

Assess assets from inside the pipe rather than from external clues

Leak detection is a necessary step to reduce water loss and prevent major water main breaks. The benefits of leak detection are obvious in increased revenues, lower risk of contamination, lower liability due to a reduction of main breaks, and increased public trust.

Although the SmartBall tool detected just one leak, the inspection gave SIMAS Oeiras e Amadora the capacity to assess assets from inside the pipe rather than drawing conclusions from indirect, external clues. If leaks are discovered early, operators can take necessary action to makes repairs before they become a major problem.

This process allows progressive operators like SIMAS Oeiras e Amadora to develop a sustainable long-term strategy for managing their critical buried assets.

Amsterdam, Holland

Would you take on a new pipeline inspection challenge, even if you knew it would land you in hot water?

Recently Pure Technologies (Pure) was able to chalk up success by adding one more type of pipeline to its inspection resumé. In this instance it was a district heating pipeline owned and operated by Eneco, one of the largest producers and suppliers of natural gas, electricity and heat, serving more than two million business and residential customers in the Netherlands.

District heating make sustainable sense

The concept of heat pipelines makes a lot of environmental sense. Throughout northern Europe, many municipalities and power generators have built closed systems of vacuum-insulated pipelines that circulate hot water from power plants and incinerators, sometimes above 100°C, through radiators in houses, businesses and other structures. This is an efficient method of heating buildings, and boasts a 98 percent heat retention rate during transmission.

SmartBall with case and insertion tools

Pure performs SmartBall leak and gas pocket detection survey

Recently Eneco contracted Pure to perform a comprehensive SmartBall® leak and gas pocket detection survey of the Centrale Merwedekanaal to WOS District Heating System. This is a 500 mm steel pipeline within a 700 mm steel pipeline of which a vacuum is created in the annular space to insulate the hot water. The survey purpose was to locate leaks and pockets of trapped gas present in the pipeline at the time of inspection.

The subject pipeline, originally installed in 1985, was suspected of having a leak, owning to an observation of water present in the annular space. As mentioned, the heating system pipeline consists of an inner 500 mm steel pipeline and an outer 700 mm steel pipeline, with a vacuum maintained in-between. The lines, constructed both above ground and below ground, incorporate numerous 90 degree bends and u-shapes, to allow for expansion and contraction as the product temperature changes.

Tracking with a laptop connected to the SmartBall

During the project, Pure inspected approximately 2.6 kilometers of the pipeline, with the goal to locate the leak(s) causing the water loss.

For the survey, Pure proposed the SmartBall leak and gas pocket detection system, a free-swimming, acoustic-based technology that detects anomalous acoustic activity associated with leaks or gas pockets in pressurized pipelines.

While other leak detection techniques such as noise loggers and correlators may identify a single leak or gas pocket between each sensor, they cannot accurately locate the limits of an anomaly nor identify multiple anomalies. In this specific case, the use of noise loggers is hindered by isolation. The SmartBall tool travels directly past each acoustic anomaly of interest on the inner pipe and thus significant advantages are recognized.

Unique challenges to overcome

The standard procedure for tracking the SmartBall tool depends on positioning acoustic sensors on the outside of the inspected pipe and listening to the device as it passes. Since the line is so well insulated from heat loss, it is also well insulated against sound transfer, which meant it unlikely for good tracking on any sensor mounted to the outer 700 mm pipe. Additionally, Eneco was understandably averse to compromising the integrity of the vacuum seal of the line, and therefore did not wish to expose the 500 mm pipe to mount sensors. In the absence of external tracking means, other reference points in the data are critical for accurately locating anomalies within the pipeline.  SmartBall contains gyroscopes that can measure bends in the pipeline that it traverses, and as there were many aforementioned 90 degree bends, these were clearly seen in the data.  The bends in the Eneco pipeline made for great geospatial reference points and therefore allowed for locating anomalies with relatively high confidence.

Pipeline over the surface

SmartBall tool deployed to survey district heating pipeline

The acoustic data recorded by the SmartBall tool was analyzed and cross-referenced with the position data. From the data collected and analyzed, the SmartBall device detected five (5) possible weaknesses, which were clearly visible in the data. Zero (0) gas pockets were detected. The results give Eneco actionable data regarding the condition of their pipeline, and despite challenges, the assessment is proving its worth. It’s a great example of a proactive utility taking efforts to maximize its capital expenditures.

Historical pipe installation

An archived photo from installation of the pipeline five decades ago.

When your pipeline operates well for five decades, it’s easy to be lulled into a false sense of security about the condition of your buried assets. Out of sight, out of mind.

Then, in an instant, that mindset can change.

For Canadian River Municipal Water Authority (CRMWA), that wakeup call happened after dealing with two unexpected failures in quick succession earlier this year. The failure repercussions quickly introduced CRMWA to Pure Technologies, a leader in technologies for the inspection, monitoring and management of critical infrastructure.

CRMWA provides water to 11 member cities in the Texas Panhandle and South Plains region, near the cities of Amarillo and Lubbock. The water authority, which serves more than 500,000 people, draws water from Lake Meredith through a 358-mile aqueduct system completed in 1966. Comprised of approximately 55 miles of non-cylinder prestressed concrete pipe (PCP) along with approximately 300 miles of reinforced concrete pipe (RCP) and bar wrapped concrete cylinder pipe (BWP), the main aqueduct can deliver up to 118 million gallons of water daily to the 11 member cities.

Digging out failed pipes

One of the pipe failures that caused a blowout.

December 30: First blowout ends flow to 9 cities

The first indication of a problem occurred with a pipe rupture on Dec. 30, 2015, which abruptly ended the flow of water to nine of CRMWA’s member cities, leaving the cities to use precious reserves or their own water.

With the initial failure of a 72-inch (1830-millimeter) diameter non cylinder prestressed concrete pipe (PCP), the water agency lost millions of gallons of water, forcing a temporary pipeline shutdown to make immediate repairs.

January 5: Soon after the first blowout was repaired, an adjacent pipe began leaking

Five days later, on Jan. 5, CRMWA completed repair number one, and started to refill the system when an adjacent pipe began leaking.

This new leak lead to an emergency mobilization from Pure at the request of CRMWA. Pure’s condition assessment technologies have helped clients prevent more than 2,300 failures worldwide, resulting in billions of dollars in savings, and hundreds of billions of gallons in water savings. Pure has also located more than 4,000 leaks on water mains using its leak detection technologies.

Broken concrete pipe exposing the internal anatomy

One of the EM anomalies verified and excavated for repairs.

January 5-6: Pure mobilized to begin a manned electromagnetic survey

The same day, a crew of three mobilized from Dallas to the failure site near Amarillo. The purpose was to conduct a non-destructive evaluation using Pure’s electromagnetic inspection technology on the pipe immediately adjacent to the damaged sections. Over the next two days, Pure scanned 8,822 feet with internal manned electromagnetics.

January 8: Based on expedited EM analysis, Pure informed CRMWA of two large anomalies in two pipes near the first failure.  Over the next two days CRMWA completed the second leak repair, and hoped for more time to conduct a third repair where Pure called a large electromagnetic anomaly.

January 11: After Pure demobilized from the job site, the client turned on the pipeline, and after flowing for 12 hours, a second failure occurred, in the area located where Pure’s EM analysis indicated a potential problem.

January 12-13: Over the next few days, Pure verified five electromagnetic anomalies in three pipes near the failure site while CRMWA completed additional repairs. Based on the verified results, CRMWA requested a total of approximately 47 miles of manned EM inspection, which was completed by mid-March.

“The electromagnetic inspection was well worth the cost. Now we know the condition of our pipelines. We know the locations of our problems. The scan revealed 16 pipes where corrosion had put the lines at risk for developing additional blowouts. Those have been repaired much more cheaply and quickly than the costs of fixing blowouts.”

Kent Satterwhite

General Manager, CRMWA

Preparing the pipeline paid off by finishing ahead of schedule

CRMWA worked around the clock leading up to the inspections to dewater and prepare the pipeline for the internal inspections. The hard work paid off well, with no holdups on the inspection progress. The excellent planning by CRMWA and Pure allowed the inspection to wrap up ahead of schedule. Once the internal inspection was completed, Pure was also able to perform a destructive calibration on a pipe section which CRMWA provided, which was helpful for the analysis of the data collected. CRMWA was also able to repair 16 pipes that were very close to failure as identified by the electromagnetic surveys.

Sometimes one unexpected pipeline problem can compel long term planning and action, as it did with CRMWA. The Water Authority now has a defined plan to assess the condition of their pipeline, giving them the confidence to move forward with greater assurance and peace-of-mind.

Man with fish inside pipe

After a long day,  Pure and CRMWA celebrated with a fish dinner, caught while draining the raw water line.

Fish inside a cooler

In order to mitigate risk, pipeline owners spend approximately $1.5 billion every year on pipeline integrity for the thousands of kilometers of pipe across North America. Pipeline integrity often employs the use of inline inspection (ILI) tools known as pigs. These pigs are inserted into a pipeline and pushed along the pipeline by the flow of product. ILI tools have multiple functions, and can be used to clean and assess the condition of the pipeline, as well as to purge different products in a multiproduct pipeline. There is a risk of the deployed pig getting stuck or lost if it is not tracked properly. Locating a lost pig can be costly to the vendors if it is not found quickly and can cause severe damage to the pipeline.

Many legacy tracking providers do not provide a record of each pig passage to prove a pig has actually passed a location. Instead, this is left to the word of the tracker and sometimes is not a reliable source of information. Trackers are not intentionally misleading stakeholders about where a pig is, but traditional methods often make it difficult to tell if a pig has passed or not.

Traditional legacy tracking providers typically use standard geophones to track and identify a pig passage. It is often difficult to determine if a pig has passed because the signal on the geophone is quick and sometimes difficult to hear. This leads to false positives showing a pig has passed even when it hasn’t.

Using more than one sensor to reduce incidents

Using Advanced Pig Tracking, pig passages are detected using multiple sensors to ensure information is defensible and reliable. Advanced tracking systems are equipped with multiple channels. These sensors work simultaneously and reduce incidents of false positives or missed pigs. Not only do these systems come equipped with multiple sensors, but they also provide stakeholders with a record of each pig passage throughout the run.

Sensor for tracking pigs

The record shows the signal of the pig passage as well as the timestamp and pig speed at the specific location. These snapshots can then be uploaded into LiveMap, and are used for real time tracking of the pig’s position, speed, and estimated time of arrival. Conventional above ground markers (AGMs) rely on triggered passage files unlike Advanced Pig Tracking AGMs, which constantly record data when turned on.

To find out more about the other myths of pig tracking, and how Advanced Pig Tracking is more reliable than traditional methods, click the link below.

Download full PDF

Over the past decade, the world has been gripped by many stories of pipeline failures, especially those with severe consequences to the environment and human life. These failures have resulted in billions of dollars in remediation costs, and understandably, this makes pipelines some of the most regulated assets in the world. The use of inline inspection (ILI) tools, such as pigs, is the most common form of pipeline integrity. Pipeline pigs are tools inserted into a pipeline and pushed along by the flow of product through the pipeline. The tool has multiple functions, and can be used to clean and inspect the pipeline, as well as to purge different products in a multiproduct pipeline. When these tools are operating in a live pipeline, it is important to know their precise location and speed, as they are very expensive to replace. A lost or stuck pig can obstruct product flow, causing unwanted service disruptions, or at worst, pipeline ruptures.
Geophone

When tracking a pig through an oil or gas pipeline, it is often difficult to know if it has passed a tracking location, especially for inexperienced pig trackers. The majority of legacy tracking is done only with a standard geophone, a device which converts ground movement into voltage, and relies solely on the word of the technician tracking the pig. By using only a standard geophone, a technician cannot reassure an ILI vendor when the pig has passed a location. The geophone can give a technician many false positives; therefore, the technician’s word will not inspire much confidence in an ILI vendor.

Lack of experience can lead to tracking challenges

To be able to identify a pig passage with only the use of a standard geophone, an experienced tracker needs to reduce the likelihood of error. Many of the trackers who are sent out in the field are inexperienced and are unable to provide this. By solely relying on a standard geophone, field technicians can easily miss a pig passing through a station, and can lead to problems later in the run. Accurate pig tracking requires the right tools and defensible data. Remote tracking can be a more efficient system and provides more concrete data than legacy tracking systems.

Reliable tools and data

The Armadillo Tracks system uses multiple sensors to track every pig deployed into a pipeline. The sensors work simultaneously and record a snapshot of each pig passage. These snapshots prove when a pig has passed a tracking location and helps ILI vendors with benchmarking and reporting. With more reliable tools and data, vendors can have peace of mind knowing problems during a pig run will be minimized.

Technical map generated by Pure & Armadillo Tracks

To learn more about how remote tracking systems benefit ILI vendors and the other myths of pig tracking, download the White Paper here.

Download full PDF

Houston and Oaklahoma

Sahara® technology is winning accolades from satisfied owners and operators of buried infrastructure the world over. In North America, two recent projects demonstrate the benefits of using this in-line tethered tool for critical leak detection surveys, especially when speed and accuracy are paramount.

Sahara Diagram

Sahara is the first tool designed for live inspection of large diameter mains, and one of the most accurate tools available for detecting and locating real-time leaks, gas pockets and structural defects in complex networks typically found in urban environments.

The tool is inserted via a valved appurtenance, and then moves through the pipeline using the flow of water and a small drag chute – all without interrupting service. Once the sensor tool is inserted, it remains tethered to the surface. This allows for real-time results and maximum control, as the tool can be winched back and forth to immediately confirm suspected leaks and other anomalies. The sensor is also tracked at ground level by a staff member, allowing for precise spot markings for excavations.

Oklahoma City welcomes Sahara leak detection survey on critical main

In March 2015, McKee Utility Contractors (McKee) retained Pure Technologies (Pure) to perform a quick-turnaround leak detection survey on a troublesome 72-inch Transmission Main (TM) in Oklahoma City. The critical TM, which is composed of prestressed concrete cylinder pipe (PCCP) and transmits potable water, is owned and operated by Oklahoma City Water Utilities (OCWU).

In this instance, OCWU suspected a leak along a low point of the line where surface water was noticed. A previous catastrophic failure on the line compelled the utility to call on the prime contractor McKee to dig, locate, and repair the leak.

Thwarted by two days of digging and not finding the leak, McKee called on Pure to assess approximately 4400 feet of pipe and to determine the location of the leak source and any gas pockets using Sahara leak detection technology.

Quick mobilization, short turnaround timing

The planning and execution took place in short order. McKee contacted Pure on Saturday, the project planned on Sunday and by Monday a field crew and equipment were mobilized to the site in Oklahoma City. On Tuesday, a single inspection was performed, and one (1) leak was detected 360 feet downstream from the Sahara insertion point. The leak was classified as a large leak based on the audible range.  The inspection continued for a total inspection distance of 546 feet.  No other leaks were detected at the time of inspection.

By the time Pure began extracting the Sahara tool, McKee had ordered a backhoe enroute, and by afternoon the pipe was excavated, the leak located, and the repairs were able to begin.

Shane McKee, president of McKee was extremely pleased with the accuracy of the Sahara technology and the fast turnaround from the Pure team.

“Based on the results I’ve seen, I’m never again digging up another pipe again without Pure and its technology to help guide the process.”

Shane Mckee

Shane Mckee, McKee Utility Contractors

Sahara Insertion Tool

Houston energy company deploys Sahara tool to quickly locate leak in chilled water line.

Large cities often operate central chilled water plants to cool water that is then sold to building owners for use in air conditioning.

In Houston, Enwave Houston delivers chilled water through 5.4 miles of pipe to air-condition 24 buildings, including Minute Maid Park, home of the Houston Astros. The 27,000 ton system uses ice storage technology to help keep central business district buildings comfortable in spite of summer`s high temperatures and humidity.

In December 2015, Pure was retained by Boyer Inc. to perform a Sahara inspection on Enwave`s 24-inch Chilled Water Supply pipeline (CWS) and also on their 24-inch Chilled Water Return pipeline (CWR). The purpose of the inspection was to locate a suspected leak on one of the dual lines that run parallel along the downtown core.

Data identified events associated with leaks and air pockets.

Boyer proposed two separate insertions during the planning phase. Pure completed both proposed insertions over a two-day period for a total of 795 feet of pipeline inspected. Acoustic data was collected and recorded during the inspections as the Sahara sensor traversed the main. The data was evaluated to identify events associated with leaks and pockets of trapped air.

During the inspections, one leak and zero air pockets were detected. The Sahara sensor was tracked above ground to track the sensor along each pipeline and verify the endpoint of each endpoint. The leak was located 144 feet downstream from the insertion point on the second day with sub-meter accuracy, allowing a pinpoint excavation to be made for repairs, minimizing disruption to downtown Houston traffic, and minimizing the contractor`s cost of excavation and road restoration.

When time and accuracy matter, utilities count on the Sahara platform.

The two case studies demonstrate the efficacy of the Sahara leak detection system. When time and pinpoint accuracy matter, the Sahara platform gets the job done right.

SmartBall on a net at the end of a pipe

For this leak detection survey, Pure’s innovative free-swimming acoustic tool gathered critical information about the aging pipeline assets of this historic Arabian city.

This large public utility supplies bulk water to this bustling, historic resort city located in the Arabian Penninsula region. The city’s infrastructure – above ground and below – has recently been modernized to keep up with growth and support the expanding tourist industry.

Recognizing that its underground infrastructure was reaching the end of its service life, the water utility called on Pure Technologies Abu Dhabi (Pure) and its local agent International Aramoon Company, to perform a series of SmartBall leak detection surveys on 150 kilometers (93 miles) of its ductile iron pipe (DIP) water network.

SmartBall gathers critical information about the city’s buried pipeline assets

Every pipeline is unique and comes with its own set of assessment challenges. When an operator has a strong understanding about the risk and operational conditions of their system, an appropriate and defensible inspection plan can be developed.

For this project, Pure introduced its proprietary SmartBall leak detection platform to identify and locate leaks and pockets of trapped gas along the water pipeline.

Pure began the SmartBall inspection project facing a number of challenges. For starters, due to limited access to historical drawings, the pipeline system and route was relatively unknown, with only a scanned copy of the schematic available for review.  Operational challenges included fluctuating flows within the pipeline, as well as a lack of access points for insertion and extraction.

To make matters more difficult, Pure faced issues related to the isolation of branches during the inspection.  The utility could not provide the option for a valve exercise prior to the trial “dummy” SmartBall run, which was decided on to eliminate the chances losing the real SmartBall.

Acoustic intensity of anomaly and actual leak located

 Left: Acoustic intensity of anomaly.   Right: Actual leak located

SmartBall acoustic tool collects data as it rolls through the pipeline

Pure began the project with an ocular visit attended by the client and a pipeline maintenance operator to understand the right of way and alignment of pipeline sections. The distances between pipeline features were measured using an odometer, while bend locations were assumed based on street references from the schematic drawing.

Since the pipeline was non-redundant and could not be shut down, insertion and extraction points were provided by hot tapping the pipeline.

Prior to the official SmartBall launch, Pure conducted a trial run with a dummy ball on each pipe section to eliminate the chance of losing the SmartBall on its journey. Both the dummy ball run and SmartBall inspection were deployed on the same day to reduce the possibilities of flow fluctuations.

As the free-swimming SmartBall tool rolls through the pipeline, it collects acoustic data. The acoustic sensor identifies the sound of water leaving the pipeline, or the sound of trapped air at the top of the pipeline, which can reduce water flow and increase strain on pumps.

Easy to deploy, SmartBall also makes it easy to screen the pipeline for leaks, which could indicate a structural problem that deserves further attention.

Assessment identifies 21 leaks on 68 kilometers of pipe

To date, the SmartBall tool has inspected more than 68 kilometers (29 miles) of pipe within the city’s network, with additional runs planned. The inspection resulted in the identification of 21 leaks of various sizes. Of the total, 14 leaks have been verified and repaired by the utility.

The investigation confirmed that with good condition assessment, asset life can be extended, while managing utility’s exposure to risk. This mindset sets a good example for other Arabian cities to follow in developing a sustainable long-term strategy for managing aging infrastructure.

Flower Mound Sign

Named for a prominent landmark mound with more than 175 species of wild flowers, the Town of Flower Mound is ranked as one of the ten best places to earn a living and raise a family in Texas.

To complement these natural and economic positives, the scenic Town of 70,000 is also known for its municipal water stewardship and proactive approach in maintaining the quality of its buried infrastructure. This includes 430 miles of water mains and 230 miles sewer pipes serving 22,000 residential and industrial connections.

As part of the ongoing program for condition assessment of its buried infrastructure, the Town recently retained the services of Pure Technologies U.S. Inc. (Pure) to conduct a Sahara® leak and gas pocket detection inspection of approximately 21,200 feet of the Potable Water Main (PWM), which connects the Pintail Pump Station to the Waketon Water Tower. Constructed in 1973, the critical section of 20-and 30-inch pipeline is comprised of bar-wrapped (AWWA C303)steel and ductile iron pipe.

“Most pipelines are designed for 50 to 75 years expectancy, and service life can vary depending on factors such as depth, soil conditions and pipe material,” said Randy Williams, Utility Services Manager of Flower Mound Public Works (FMPW) District. “Rather than waiting for breaks to happen, the Town strives to assess the condition of the assets before that happens.”

The Sahara inspection followed a structural assessment using a PipeDiver® inspection of this same pipeline conducted one month earlier and covered many of the identical pipeline sections. FMPW chose CCTV inline video and enhanced electromagnetic (EM) assessment to provide a comprehensive condition assessment.

PipeDiver platform carried to the insertion point

Pure’s free-flowing PipeDiver platform, which preceded the Sahara inspection along the same pipeline, is being carried to the insertion point.

Detecting small leaks with Sahara inspection platform

The Sahara® pipeline inspection platform is one of the most accurate tools available for leak detection, gas pocket detection, and locating structural defects in complex networks of large diameter water and wastewater pipes.

The tethered tool is capable of locating very small leaks typically within 1.5 feet (0.5 meters) of their actual location. The tool also features inline video that allows operators to observe internal in-service pipe conditions.

Added value: Flower Mound inspection included design and installation of taps

The insertion locations for the Sahara inspection were dictated by the previous PipeDiver inspection, which indicated a large number of bends and long distances to cover with less than ideal access.

In light of the limitations, and within a very short time frame, Pure took on the responsibility to manage the tapping process in-house, including the design, excavation and installation of the taps to insert and extract the Sahara tool from the pipes. Although this task was atypical of work normally provided, it is an example of the added value Pure can bring to a project.

Detected: one leak, one large gas pocket, plus improved GIS information

It’s still early in game, and the electromagnetic results have yet to be fully evaluated. Nonetheless, the Sahara inspection detected a leak on an undocumented offtake installed on pipe suspected to have been blanked off and buried, and now leaking.

In addition to pinpointing the leak and gas pocket, the condition assessment located an additional six undocumented outlets the Town was previously unaware of, leading Pure and FMPW to surmise that the outlets were installed and equipped with blind flanges for future expansion. Additionally, during this inspection, sections of pipeline alignment were discovered to be quite different than what FMPW expected.

FMPW now has a true comprehensive condition assessment of their pipeline that includes GIS quality mapping, video inspection and recording of the pipeline interior, leak and gas pocket identification and repair, and assessment of the structural integrity on a pipe-by-pipe basis — allowing for localized verification and repair. Overall, GIS information has been improved, with location and images of possible leaks, defects or anomalies.

“The proactive approach we’re taking allows us to predict water main breaks, which improves our reliability of service,” said Williams. “When you locate a defect, you can schedule a repair, notify people, and get it done at the right time of day, and at a schedule of our choosing. Everybody benefits.”

Randy Williams, Utility Services Manager of Flower Mound Public Works (FMPW) District, talks about the Utility’s approach to condition assessment.

Scottish Water takes innovative and responsible approaches to pipeline management. To assess the condition of its Newmore Raw Water Main, the water provider used PipeDiver™ inline inspection technology, the first use of the technology in Europe.

Scottish Water (SW) is the fourth largest water and wastewater provider in the United Kingdom (UK), serving more than 5 million customers in 2.4 million households. As one of the country’s largest businesses, with a £1 billion (US$1.54 billion) annual turnover, SW also acts as the wholesaler of water and wastewater services in the competitive market for business customers in Scotland.

A leader in the industry, SW has long undertaken innovative and responsible approaches to pipeline management. For its inventory of strategic infrastructure assets, the water operator is employing advanced techniques to build detailed criticality and integrity profiles. These profiles will be used to develop and maintain dynamic and fully detailed pipeline management plans.

Spray released from air valve and Pure crew readying PipeDiver for insertion

(Left) Pure and Scottish Water crew standing by as spray released from air valve. (Right) Pure crew readying PipeDiver for insertion to assess condition of Newmore Raw Water Main.

Inspection covered 14.6 kilometers (9.1 miles) and spanned 3,382 pipes

Scottish Water had long been working on conducting a risk-based condition assessment of its transmission main that delivers raw water from the Redburn to a reservoir feeding the Newmore water treatment plant, in the Inverness region of Scotland.

The purpose of the inspection was to locate and identify leaks and pipes with stress, using proprietary leak detection and electromagnetic technologies. The inspection covered 14.6 kilometers (9.1 miles) and spanned a total of 3,382 pipes composed of 685-millimeter (27-inch) and 762-millimeter (30-inch) pipe.

PipeDiver technology locates and quantifies stress

Pure Technologies, in partnership with WRc, began its initial screening assessment in March 2015 with SmartBall™ technology, a free-swimming leak and gas pocket detection tool used to record acoustic data on the pipeline. This data was evaluated to identify acoustic anomalies associated with leaks and pockets of trapped gas.

From the data, Pure identified 5 anomalies associated with leaks and no acoustic anomalies characteristic of pockets of trapped gas.

In August 2015, a few months after completing the leak detection survey, Pure mobilized its team to undertake a first within Europe – a structural condition assessment using PipeDiver™ technology, an inline tool used to locate and quantify distress.

The PipeDiver tool is free-swimming and comprised of three parts – a battery module, electromagnetic module and a tracking module. The electromagnetic sensors are located on each fin and collect a magnetic signature for each pipe section to identify anomalies that are produced by damage to the structural component for the integrity of the pipe.

Inspection results

The inspection determined 12 pipes with EM anomalies consistent with pipe distress damage.

To repair, replace or leave alone? That is the risk-based question

The PipeDiver inspection determined that 12 pipes in the Newmore Transmission Main displayed electromagnetic anomalies consistent with damage. Effective analysis of electromagnetic data first requires baseline knowledge of how the electromagnetic signal behaves when no damage is present. This baseline is then compared to the data signal received when damage occurs on the pipe. To understand how the data signal responds, Pure performed calibration scans on pipes similar to the inspected pipe, provided by Scottish Water.

While the electromagnetic technology provides data for structural deterioration, the challenge is to determine how much damage creates an unacceptable level of risk, thereby requiring intervention actions.

Pure has developed an innovative approach for pipeline management using structural models along with hydraulic evaluation data to deliver a Pipe Performance Curve used for the management of a pressure main. The decision-making tool plots stress versus pressure, and will allow SW to understand when a pipe is trending toward ultimate failure, which in turn will help in making defensible investment decisions.

Utilities Complete Condition Assessment Of Bar-Wrapped Pipe With Smartball®, Pipediver®, And Robotic Platform Tools

By the early 1940s, cast iron pipe was losing its historic cachet as the go-to material for new buried infrastructure. Cast iron’s replacement was bar-wrapped pipe (BWP), and it quickly gained acceptance as a reliable, durable and cost-effective pipe material for use in large-diameter transmission and sewer force mains.

Typically, BWP consists of a welded steel cylinder with reinforcing bars wrapped around the cylinder to provide strength. An internal concrete lining and external mortar coating provide corrosion protection to the steel components. The watertight membrane enables the composite pipe to withstand high internal pressures and the effects of external earth and traffic loads.

Until recently, BWP condition assessment proved difficult

Despite early adoption from many pipeline operators, the downside to BWP has been the difficulty to assess the pipe’s condition, where failures are often precipitated by deterioration of the reinforcing bars and long periods of leakage that often go undetected.

It’s now 70 years later, and the methods to assess the condition of bar wrapped pipe have only been recently developed and commercialized. On this forefront, Pure Technologies is recognized for its toolbox of condition assessment technologies that can identify broad areas of cylinder corrosion and bar breaks.

Two Texas cities join forces to assess shared BWP water supply line

In one specific case, the city of Irving and a partnering agency in North Texas joined together to initiate a condition assessment project of their shared water supply line, made up primarily of bar-wrapped pipe. Constructed in 1955, the 48-inch Jamison Water Transmission Main is a critical non-redundant pipeline that conveys potable water to a combined population of 400,000 residences within the Dallas Fort-Worth Metroplex.

The two agencies worked side by side to implement an Assess and Address™ pipeline inspection protocol to determine the condition of the pipeline and to increase the utilities’ reliability of water delivery.

The condition assessment utilized inline acoustic leak and air pocket detection, robotics with high definition CCTV and enhanced electromagnetic detection, transient pressure monitoring and non-linear Finite Element Analysis (FEA) of the steel cylinder corrosion and broken bar wraps.

The results concluded that 97 percent of the 583 pipes inspected had no detectable damage. Less than 3 percent of the total pipes inspected exhibited minor distress, of which 15 (2.5 percent) pipes exhibited thinner steel cylinder.

Through close collaboration, the two agencies were able to effectively manage a shared asset with the goal of preventing disruptive and expensive pipe failures. The information gained from the assessment will allow for the implementation of a cost-effective, long-term management plan to extend the life of the pipeline.

Trinity River Authority of Texas (TRA) evaluates 8.8 miles of critical BWP transmission main

In a second case involving BWP, Pure collaborated with Trinity River Authority on assessing the condition of a pipeline that is a critical link in the reliable delivery of drinking water to five cities within the Dallas-Fort-Worth Metroplex. The aging pipeline was scheduled for replacement due to previous failures and inability to be removed from service for repairs.

To understand the overall pipeline condition, TRA contracted Pure to inspect and evaluate the pipeline by conducting comprehensive hydraulic, leak detection and condition assessment on 8.8 miles of the 30-inch bar-wrapped pipe.

For the leak and air pocket assessment, TRA used the SmartBall® inspection tool, a non-destructive, free-swimming technology that measures the acoustic activity associated with leaks and gas pockets in pressurized pipelines. Regular leak detection inspections can help utilities identify leaks that may not be visible at the surface.

Increased reliability, reduced capital costs

For the structural inspection, TRA used PipeDiver®, a free-swimming electromagnetic tool that identifies bar breaks and broad areas of cylinder corrosion in BWP using PureEM technology while the line remains in service.

The inspection of the BWP identified 14 pipes with bar break damage and 72 pipes with electromagnetic anomalies resembling cylinder defects out of 1284 inspected pipes. By repairing specific pipe sections with deterioration, TRA was able to avoid replacing the entire pipeline at a high capital cost and continue providing reliable service to customers in the region.

Dallas Water Utilities Discovers Massive Hidden Sinkhole And Achieves Huge Savings Through Annual Leak Detection Program

The year began with the Lone Star state experiencing its fourth year of drought, compelling State Governor Greg Abbott to reissue an Emergency Disaster Proclamation in early May to deal with the declining aquifer levels and severe water shortages. Only a few weeks later, torrential rains flooded so much of the state that the Governor issued another Emergency Disaster Proclamation to prepare for the new crisis. Then, another long stretch of baking heat.

Weather extremes push water utilities to the limit

For most utilities, weather can play havoc with buried infrastructure. While drought can cause the dry brittle ground to shift and pipes to break, excessive rain can result in washouts, loss of bedding and risk for accelerated pipe failures.

In 2015, weather extremes in such a short period taxed water utilities across Texas. Despite the challenging environmental conditions, Dallas Water Utilities (DWU) moved forward to carry out its annual leak detection program. Over the years, DWU has focused its water loss reduction efforts on both its critical large-diameter transmission mains, which have the highest consequence of failure, and on its distribution systems.

Pipe leaking

Detection results include discovery of a large pipe leak near a major roadway

Staff inserting Sahara tool

Crews successfully used the Sahara® tool to locate 10 leaks in 16 miles of inspection.

DWU’s first condition assessment program using electromagnetics was completed in 2001, followed by the use of newer leak detection technologies in succeeding years. The program is now in its 14th year of operation, and DWU has become a showcase utility for proactive pipeline management, a fact recognized by the Texas Water Development Board.

DWU adds 16 miles to its leak detection program in 2015

DWU’s distribution system is one of the largest in the United States, being a regional provider, the utility delivers water service to 2.4 million customers within the Dallas and surrounding city limits. The major distribution system includes over 4,900 miles (7,800 km) of distribution and transmission mains.

DWU’s goal is to continually evaluate, upgrade and replace its water and wastewater assets in order to make its systems operate efficiently. DWU’s long-time partner in this infrastructure endeavour is Pure Technologies (Pure). This year Pure was contracted to perform leak and air pocket detection for 16 miles (25.7 kilometers) of water mains made of a variety of materials, including prestressed concrete cylinder pipe (PCCP), cast iron pipe (CIP) and ductile iron pipe (DIP).

DWU deploys inline detection tools

For inspection of its transmission mains, DWU has long used Sahara leak detection and inline closed circuit video (CCTV) provided by Pure. More recently, DWU has also used SmartBall® technology for longer inspections.

Sahara is the first tool designed for live inspection of large-diameter mains, and one of the most accurate tools available for detecting leaks, gas pockets and structural defects in complex networks typically found in urban environments.

The tool is pulled by the flow of water by a small drag chute while the line remains in service. When the sensor is inserted into a 2-inch tap, it remains tethered to the surface. This allows for real-time results and maximum control, as the tool can be winched back and forth to immediately confirm suspected leaks and other anomalies. The sensor is also tracked at ground level by a staff member, allowing for precise spot markings for excavations.

Detection results include discovery of massive sinkhole near major roadway

The 2015 inspections, conducted over 23 days, challenged the Pure and DWU crews as they faced an environment with temperatures soaring to 104°F (41°C) on many consecutive days.

In spite of the trying working conditions, the crews successfully used the Sahara tool to locate 10 leaks in 16 miles of inspection. This included the unexpected discovery of a very large leak in the barrel of a 12-inch ductile iron water main. DWU’s proactive repair prevented a collapse since the large leak was creating a cavernous sinkhole near a major roadway.

By locating and repairing the leak, which had been seeping water for an estimated year, DWU averted a potential catastrophic crisis and saved the utility at least 893,000 gallons of lost water per year, equivalent to filling 1353 Olympic-sized swimming pools.

Olympic-sized swimming pool

Large leak discovery saved DWU at least 893,000 gallons of lost water annually, equivalent to filling 1353 Olympic-sized pools.

Sahara and SmartBall inspections in Dallas have been extremely successful, locating 160 leaks in 209 miles. The estimated water savings from these leaks is about 4 MGD. For DWU, the reduction in failures has reduced loss claims and service interruptions, as well as reduced treatment and delivery costs.

Whatever the weather, DWU is moving forward.

The Usutu Water Scheme supplies raw water to a number of coal-fired power stations and towns in the Mpumalanga province of South Africa. The bulk water pipeline, completed in the late 1970s, consists of large diameter (DN1300 mm) pre-stressed concrete non-cylinder pipe (PCP) that links two mains for a total of 90 kilometers between the Rietspruit, Davel and Kriel Reservoirs.

Recognizing that the infrastructure might be reaching the end of its lifespan, the Department of Water and Sanitation (DWS) called on SSIS Pipeline Services, which represents Pure Technologies in South Africa, to conduct a comprehensive condition assessment of the pipelines.

Destructing the old to help evaluate the current pipe state

Due to a lack of records, DWS provided Pure with old removed pipes, as well as spare pipes that were destructively evaluated to determine the design specs and calibrate the electromagnetic signal to accurately detect wire breaks.

Every pipeline is unique, and if a utility has a strong understanding of the operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed, pipe by pipe. Pure came onboard bringing its inspection, risk assessment and engineering analysis services, along with its comprehensive suite of technologies to survey the pipeline for leaks, gas pockets and wire breaks.

Civil Engineering Cover June 2015

Pipediver Field crew operators insert the PipeDiver inspection tool into the pipeline.

Field crew operators insert the PipeDiver inspection tool

Pipediver Field crew operators insert the PipeDiver inspection tool into the pipeline.

Ostrich

Project begins with leak detection surveys

For DWS, Pure and SSIS began with leak and air pocket detection surveys, employing Pure’s proprietary SmartBall™ technology. As the free-swimming SmartBall tool rolls through the pipeline, it collects acoustic data. The acoustic sensor identifies the sound of water leaving the pipeline, or the sound of trapped air at the top of the pipeline, which can reduce the water flow and increase strain on the pumps.

Easy to deploy, the SmartBall tool is an excellent screening tool for PCP inspection programs by identifying leaks and air pockets in the main. These areas provide a preliminary look at the condition of the pipeline.

As a follow-up to the SmartBall survey, SSIS employed its Sahara® platform, a tethered tool with attached audio-video surveys to gain a better understanding of the leak locations along the pipeline. A total of ten leaks were detected and accurately located using SmartBall and Sahara.

PipeDiver™ electromagnetic survey evaluates the pre-stressing wires

Because the Usutu pipelines could not be taken out of service, crews inserted Pure’s revolutionary PipeDiver™ tool, which features collapsible fins that allows it to pass through sharp bends, diameter reductions and butterfly valves as it is carried by the flow of water.

The free-swimming PipeDiver inspection platform uses electromagnetic (EM) sensors to evaluate the existing condition of the pre-stressing wires. EM inspections collect a magnetic signature for each pipe section to identify anomalies that indicate zones of wire break damage. The presence of wire breaks in concrete pressure pipe is often a sign of impending failure. This inspection method is the best available technology to determine the baseline condition of the PCP mains.

While the PipeDiver survey was performed, the critical pipeline remained in operation. The entire 90 kilometers of pipeline was inspected in three runs, and the inspections found the majority of pipes to be in good condition.

Investigation replaces uncertainty with peace-of-mind risk assessment

In addition to using to the monitoring technologies described above, Pure also conducted a variety of other risk assessment and engineering analysis services for the project.

This included field verification data to compile a calibrated hydraulic model to mime the steady state and transient behaviour of the pipelines. The results showed that DWS’s current operating procedures worked well to control the flow and prevent pressure surges.

Pure Technologies also completed a finite element analysis (FEA) to quantify the structural ramifications of the broken pre-stressing wires detected by electromagnetic inspection. This analysis was used in tandem with the electromagnetic inspection results in the risk assessment.

DWS sets a good example for managing its transmission main assets

The project highlights the value of embracing a proactive pipeline condition assessment programme using best practices, expertise, and cutting-edge technology.

The investigation confirmed the asset life can be extended, while managing DWS’s exposure to risk and sets a good example for other South African utilities to follow in developing a sustainable long-term strategy for managing their asset

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A ruptured sewer pipe can attract a lot of unwanted attention, even when it happens on private property. Last year, hours before celebrities were to arrive at the Golden Globes Awards show at the Beverley Hills Hotel, a reputed sewer pipe burst, spewing a mess of wastewater on the red carpet, according to media reports. When large pipes fail, it’s usually breaking news. And when the failed pipeline is part of a pressurized wastewater force main network, repercussions to the environment and the public have the potential to be catastrophic, with fallout to a utility’s reputation. In Canada, pressurized force mains that carry sewage make up only about 7.5 percent of the typical wastewater system compared to gravity mains. Because sewer force mains tend to run constantly, and often operate without redundancy, there is little opportunity to assess the pipes. When problems arise, and a critical force main is out of commission, the entire wastewater system can stop, causing overflows or the need to implement costly bypass pumping. Worse still, pollution generated by a raw sewage leak can flood to the surface and into a watercourse. Clean-up costs can be staggering and environmental impacts can be devastating.

PureRobotics device

The PureRobotics platform can assess the structural integrity of force mains and provide inline video to observe internal pipe conditions.

Force mains have unique signs of impending failure

Internally, force mains have unique warning signs of failure. Because of the sewage flow, trapped gas pockets can allow concentrations of hydrogen sulfide gas to be released from solution and subsequently convert to sulfuric acid by bacteria on the pipe wall, leading to corrosion of the pipe wall. As the pipe wall corrodes internally, it becomes weaker and more likely to fail unexpectedly. While corrosion and defect failures on sewer pipelines are a fact of life for wastewater utilities, these failures do not occur systemically. As a result, knowing when to replace and when to preserve assets through close inspection is more critical than ever.

SmartBall with extraction tool and controls

Managing force mains proactively can help utilities prevent environmental regulation violations that are expensive to mitigate.

Addressing the high consequence of failure in wastewater pipes

Aging pipes, increasing costs of failures and high replacement costs represent significant challenges facing force main owners. As a result, utilities have come to rely on Pure Technologies for its suite of technologies that can identify the weak links. Selective rehabilitation of force mains maximizes the life of the asset, typically at 10-15 percent of replacement costs. Pure’s strategy employs a risk-management approach that looks at likelihood of failure (LOF) and consequence of failure (COF). LOF variables are related to the chance that a pipe could fail, and include: pipe age, material, operating conditions and soil conditions, among other things. COF variables may include the pipe size, its location, environmental and social consequences of a rupture, interruption to service and tarnished public reputations.

Low risk assessment

For low risk force mains, screening and desktop evaluations such as hydraulic analysis and pressure management within the system are often enough to manage the assets. As risk goes up, however, utilities should look at higher resolution technologies that offer more confidence for higher predictability.

Medium resolution assessment

The SmartBall® Pipe Wall Assessment (PWA) tool is Pure’s best technology for identifying leaks, gas pockets and wall stress locations in metallic sewer force mains. PWA technology looks at pipeline walls affected by loading and bedding conditions, as well as other factors that cause stress on the pipe, including structural damage caused by internal or external corrosion. As the free-swimming SmartBall tool rolls through the pipeline, it collects both acoustic and electromagnetic (EM) data. The acoustic sensor is used to identify the sound of wastewater leaving the pipeline, or more often, the sound of trapped gas at the top of the pipeline. Trapped gas within a force main may lead to internal corrosion and eventual breakdown of the pipe wall which is the primary cause of force main failures. In addition to the acoustic data, the SmartBall platform also collects EM data to identify areas of the pipe wall that are under stress. Areas of the pipe wall with damage will be under more stress than areas with limited or no damage. Stress on the pipe wall can also be caused by other factors such as excessive loading and hard bedding surrounding the pipe. Recent developments in SmartBall technology now allow for the combination of leak and gas pocket surveys with PWA surveys in a single deployment, providing a complete screening tool for force mains. Based on initial surveys using the SmartBall PWA tool, areas where gas pockets overlap with stress anomalies represent the largest area of concern of force main owners, as it indicates a high likelihood of corrosion.

High resolution assessment

In force mains with a higher risk, utilities should also consider assessment with a higher resolution tool in addition to a pre-screening survey that detects anomalous changes. For lines that cannot be taken out of service, Pure can deploy the PipeDiver tool, which uses electromagnetic sensors to detect areas of damage along the pipeline. The inline inspection system is an innovative, free-swimming condition assessment platform specially designed for in-service inspection of pressure pipelines. Configured with PureEM™ sensor arrays, the tool can be used with precision to identify wire breaks in PCCP and broad areas of cylinder corrosion in metallic pipe.

No one solution for every pipe or pipeline

While there is no silver bullet for assessing every pipeline, if a utility has a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows force main owners to develop a sustainable long-term strategy for managing their critical force main assets.

This notion came to life in a North American survey conducted in 2014 and published online this year in The American Water Works Association Journal on current sustainable infrastructure practices among water and wastewater utilities.

Authored by associate professor Amy Landis, the survey found that of the 125 American utilities that responded, less than half “failed to implement some form of sustainability practice, which ranged from renewable energy to infrastructure repair to demand management. Of the respondents, only 18 percent of utilities reported publishing a sustainability policy or vision.”

Surprising results in spite of critical importance

The results are rather surprising, considering that sustainable water infrastructure is critical to providing the American public with clean and safe water. The American Society of Civil Engineers (ASCE) gives drinking water and wastewater infrastructure a “D” grade, which puts the infrastructure in “poor and at risk” with most of the assets approaching end of service life, some reaching the age of 100 years old or more.

For combined water and wastewater utilities, the most common selected metric to evaluate sustainability practice was “water consumption and/or water delivery efficiency” at 63 percent. Coming in second for sustainable infrastructure practice was “employ trenchless pipe repair and/or rehabilitation.”

Old main

Buried assets are approaching end of service life, some reaching the age of 100 years old or more.

Helping water utilities embrace sustainability

The good news is that it is easier today for public water utilities to move forward on the path to social, environmental, and economic sustainability. Modern inline technologies and precise data analysis tools certainly help the effort.

For more than a decade, Pure Technologies has played a key role in helping progressive utilities follow through with actions to promote sustainable practices for their water and wastewater infrastructure.

Sustainable practices include helping pipeline owners optimize capital and remaining useful life as they seek to more efficiently manage their assets.

As a trusted global leader specializing in the assessment, monitoring and management of pressurized pipelines, Pure has completed structural condition assessment on more than 8,000 miles of critical water mains. This has helped utilities avoid critical pipeline failures that can be expensive to remediate and damaging to their reputation. In addition, Pure has located more than 4,000 leaks on mains using inline leak detection. Through these activities, billions of gallons have water have been saved through repaired leaks and avoided pipe failures.

Pipe Surface Inspection

By understanding the operational conditions in their system, utilities can develop a defensible plan for managing their infrastructure.

Capital savings can be invested back into the system

The numbers continue to impress. Based on Pure’s condition assessment data, we have found that 96 percent of pipe sections do not have any deterioration at all and are in “like new” condition, while less than 1 percent of pipe sections require immediate repair. This is comforting information to utilities with aging pipelines still in operation, as is the case with the remarkable cast iron water main buried in 1831 beneath what is now Greenwich Village.

By identifying and repairing isolated sections that require intervention followed by a long-term management strategy, a utility can realize major capital program savings over replacement or large-scale rehabilitation. On average, a utility owner can proactively manage a pipeline for 5 to 15 percent of the capital replacement cost. The money saved can be invested to fix and sustain other parts of the system.

The U.S. EPA and ASCE estimate the funding costs associated with buried infrastructure ranges from more than $200 billion to 1 trillion over the next 25 years. The numbers are staggering. Pure Technologies is helping utilities manage their buried infrastructure through its Assess and Address™ approach to pipeline management, and as result, has saved clients hundreds of millions of dollars in replacement costs.

Public pressure to do the right thing

With drought, climate change and water conservation now part of the daily conversation, the pressure is on for public utilities to incorporate sustainable practices into their planning. It’s the right thing to do, from an economic, environment and social standpoint.

By having a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows utilities to develop a sustainable long-term strategy for managing their infrastructure well into the next century.

Metallic pipes have a long history in distribution systems throughout North America, with cast iron and carbon steel making their debut in the early 1800s. In many states, pipelines deploying the early metal are still in service, including the cast iron water main buried in 1831 beneath what is now Greenwich Village.

Risk prioritization as a starting point

Before undertaking any metallic pipe inspection, a utility should first complete a risk prioritization of all their buried assets, factoring in a variety of consequence of failure (COF) and likelihood of failure (LOF) variables to determine the highest/lowest risk pipelines. A distribution pipe buried in a cornfield probably has a lower risk profile than a water main buried under a children’s hospital.

This first step in risk analysis is critical, and can help determine a prioritized strategy. The higher the risk, the more an operator requires reliable information for an action plan to replace, rehabilitate or inspect the pipes further to gather more precise data.

Using asset risk to guide the management strategies, an operator can feel confident about implementing the right approach, at the right time, with the lowest financial impact. Overall, this strategy ensures long-term service, reliability and safe operation.

Match the technology and inspection method with the risk

This initial process also allows operators to choose the most appropriate inspection method based on different pipe material and operational requirements, including lack of redundancy.

If the analysis ranks the mains as medium to high-risk pipes, it makes sense to utilize medium to high-resolution inspection technologies. High risk pipes are probably more expensive and more difficult to replace, and probably affect more people if taken out of service.

 

Medium Resolution Technology

Pipeline Inspection and Condition Assessment Services

PureEM™

PureEM technology represents a form of non-destructive testing that provides a snapshot of the pipeline`s condition by inducing electric currents/magnetic fields within the pipe to measure an electromagnetic response. By creating these fields, PureEM data identifies specific areas of the pipe wall with large EM anomalies. In the case of metallic pipes, these anomalies typically represent broad areas of corrosion.

Typically, metallic pipes are first assessed with a prescreening tool – including inline leak detection and pipe wall assessment – followed by PureEM testing, using one of three platform tools. This multi-tool approach provides the operator with a variety of condition information that can help inform renewal decisions.

With PureEM manned inspection tools, field technicians have the option enter the pipeline with a PureEM inspection tool (e.g. push cart, bicycle) and traverse the length of the pipeline, inspecting for damage. The tool can be used in dewatered water and wastewater pipelines.

Free-Swimming Pipeline Inspection

PipeDiver®

When configured with PureEM, the free-swimming PipeDiver tool is an effective medium resolution tool to assess areas of damage along a pipeline that is live or can’t be taken out of service due to a lack of redundancy or operational constraints. It is ideal for metallic pipes with a higher consequence of failure, since the tool operates while the pipeline remains in service.

PureRobotics™ – Pipeline Inspection

PureRobotics™

Pure`s long range, multi-sensor robotic inspection vehicles are capable of conducting PureEM inspections on steel and ductile iron pipes. The robotic vehicle can be used in depressurized and partially dewatered and wastewater pipelines.

No one solution for every pipeline

Every pipeline has a unique set of conditions, which is why there is no one silver bullet that works across the board.

However, if a utility has a strong understanding of the risk and operational conditions of different areas in their system, an appropriate and defensible inspection plan can be developed. This process allows operators to develop a sustainable long-term strategy for managing their critical buried assets.

To combat drought conditions, lawn care companies have come up with creative ways to maintain their business.

Change is in the air. One only needs to check the daily news to understand why climate change, drought and water infrastructure have become frequent buzzwords heard around the water cooler.

For residents of states that stretch from the Pacific Coast to across the southwestern United States, the summer of 2015 may go down in history as one of the driest seasons on record, with widespread restrictions on water usage.

This past spring California Governor Jerry Brown proclaimed mandatory water cutbacks for all residents. Calling this “perhaps the worst drought California has ever seen since records began being kept about 100 years ago,” the Governor ordered cities and towns to cut usage by as much as 36 percent.

With the stroke of a pen, the simple act of washing your car, watering your lawn or taking a shower instead of a bath has become a conscious decision. The repercussions of water restrictions are even changing kitchen habits for cooks, restaurants and food producers, and across the nation many water-thirsty crops are forcing consumers to pay higher prices at the grocery store.

Water supplies and delivery systems threatened

Population growth, drought and severe climate changes have resulted in declining reservoir and aquifer levels, threatening water supplies and delivery systems. The water level in Lake Mead, the largest drinking-water reservoir in the United States, has dropped so much that the city of Las Vegas agreed to spend US$800,000 to build a deeper 3-mile long intake pipe to address the problem for residents and visitors.

“We have to think differently,” said Michael Connor, the deputy secretary of the Interior Department. “It’s not enough just to conserve water. We have a lot of infrastructure, but a lot of it doesn’t work very well anymore. We need to undertake what amounts to a giant re-plumbing project across the West.”

Daunting challenges demand innovative solutions

Although there are no simple solutions, the crisis has given us ample opportunity to reconsider how we use water and what we can do to conserve, reuse and repair. And while proactive water conservation is a smart way for consumers to react, the crisis puts increased pressure on water utilities to better manage their resources and pipeline networks.

One of the biggest drivers for utilities is finding ways to reduce the loss of water from leaky pipes. According to the American Water Works Association, that loss can range between 14 to 18 percent, nationwide. When a state like California distributes an estimated 38 billion gallons a day, the savings potential is immense, from both a financial and resource standpoint.

 Pure Technologies works with water utilities to help manage their resources and pipeline networks

Cutting edge leak detection technologies help preserve water

Pure Technologies, a world leader in infrastructure management, has been helping utilities and water authorities manage the life cycle of their pipeline assets for more than a decade.

To date Pure has assessed, analyzed and monitored more than 8,700 miles of pressurized pipeline, everything from distribution and transmission mains  delivering drinking water to wastewater pipelines carrying raw sewage.

Through our technical platforms and engineering services, Pure’s condition assessment technologies have helped clients prevent more than 2,300 failures worldwide, resulting in billions of dollars in savings, not to mention hundreds of billions of gallons in water savings. Pure has also located more than 4,000 leaks on water mains using our leak detection technologies.

Not surprising, the real job is just beginning, as society becomes acutely more aware of water issues.

You can’t manage what you don’t measure

Globally, utilities have come to value Pure’s expertise in helping them to sustainably manage their water networks using inspection as the cornerstone to understanding what needs to be addressed.

Getting a firm handle on water loss means taking a holistic approach. Utilities can effectively reduce their real water losses by completing regular leak detection in their distribution network using traditional leak detection tools, like correlators, combined with a transmission main leak detection program using inline tools that can accurately locate high-loss leaks.

Service providers such as Wachs Water Services can also reduce water loss through a valve management program, which improves valve condition and location information for field staff. An effective valve program allows a utility to reduce their response time – and the associated water loss – when a pipe failure does occur.

Regular condition assessment of water mains can also identify pipes that are at risk of failure, and can effectively reduce failures that result in large water losses.

All this operational efficiency is going over well with stakeholders and a more informed public that appreciates sustainable efforts and has embraced singing shorter songs in the shower.

Water and sewer utilities across North America are facing a major funding gap related to their buried pipeline infrastructure. Based on current estimates, utilities do not have enough capital available to fix or replace their aging assets. In addition to the funding gap, utilities are under scrutiny because of increased incidences of pipeline failures that are disruptive to communities and expensive to mitigate.

This new reality has forced utilities to squeeze more remaining life out of existing assets, creating more demand for condition assessment programs that allow utilities to identify specific areas of damage and selectively repair pipelines in favor of full replacement.

Historically, condition assessment has been in the realm of a few specialized firms that respond to high profile pipeline failures; however, the industry has changed and condition assessment is becoming widely used and trusted. This approach has been adopted by many utilities that have successfully managed risk and extended the life of assets for a fraction of the cost of a replacement program.

According to a study by Pure Technologies, the majority of pipelines 16 inches and above can be cost-effectively managed for between 5 and 15 percent of the replacement cost. The study found that pipeline damage is typically not systematic across an entire pipeline, but is usually localized due to factors such as design, manufacturing, installation, environmental, operational or maintenance factors.

Equipped with this information, utilities can be assured that assessing the majority of their mains before replacement can reduce their infrastructure gap and extend the useful life of assets.

However, one question that often gets asked about condition assessment programs is how a utility should choose the right condition assessment solution.

The easiest way to solve this challenge is to employ a risk-based approach to condition assessment using a variety of tools that offer different resolutions.

Staff inserting tools

Defining Risk and Pipeline Priorities

Risk is a measure of the probability and consequence of uncertain future events, in this case, potential pipeline failure. A basic approach can be used to define risk even in complex systems; simply, risk is a product of Consequence of Failure and Likelihood of Failure (CoF x LoF).

Consequence of Failure (COF) refers to the damage a failure would cause based on factors like its location, the amount of users it supplies, and its size and operating pressure. Likelihood of Failure (LOF) refers to the probability of a failure occurring based on factors such as age, pipe material, soil conditions, operating pressure, failure history, among others.

Generally, the Consequence of Failure is well defined by the potential damage a pipeline failure would impose on the surrounding environment and is generally fairly static – or – once defined, it is unlikely going to change rapidly.

With this in mind the key to managing risk, or the possibility that a pipeline could fail, is in understanding the Likelihood of Failure. This can be achieved by quantifying the physical condition of the pipeline and understanding and quantifying the factors that affect the potential for deterioration of the assets.

Once risk is defined, the pipeline inventory can be prioritized which helps in the selection of condition assessment approaches and the application of the appropriate technologies. In general, high-risk pipelines warrant a detailed assessment while low risk pipelines can use lower resolution alternatives.

Using Risk to Select Condition Assessment Techniques

When selecting condition assessment techniques, qualifications and technical judgment should be used in lieu of price. High resolution tools come with a higher cost, but saving money on a low resolution condition assessment is not a responsible alternative for a high-risk main.

For example, the savings gained by selecting a low resolution technology for a large-diameter pipeline with a high CoF are often miniscule in comparison to the repair and capital programming decisions that result from the low resolution condition assessment data. If the data is inconclusive or inaccurate, a utility may unnecessarily invest millions in a capital replacement program that was not required, easily eliminating the savings achieved by selecting the less expensive condition assessment option.

Tech monitoring results

Additionally, the cost of a failure should be considered when selecting a lower-cost assessment for a critical pipeline. The average cost of a large-diameter pipe failure is between US $500,000 and $1.5 million; money saved on lower-resolution assessments can easily be negated by the cost of mitigating a single failure and the resulting reputational damage.

One method of selecting a technology is to compare uncertainty to risk. As mentioned earlier, risk is a measure of the probability and consequence of uncertain future events. When dealing with a high-risk asset, it is important that the solution allows the utility manager to minimize the uncertainty of the condition assessment. More importantly, it is crucial that the utility manager knows the condition of the asset to the best extent possible, particularly in areas where there is a high Consequence of Failure.

Pure Technologies has a suite of condition assessment tools with different resolutions. Our low resolution solutions can provide basic condition data on leaks, air pockets and areas of pipe wall stress that could represent damage. This is a valuable prescreening option for high-risk mains, or alternatively for lower risk mains, can be enough detail for a utility to manage the asset.

Pure’s medium and high resolution tools provide more comprehensive data for higher risk pipe. Our high resolution tools can provide detailed accuracy, for example, locating small pits on metallic pipe. The data collected from both medium and high resolution tools is often used by utilities to create rehabilitation plans for critical mains.

Regardless of the solution provider, it is important that utilities employ a balanced, risk-based approach to condition assessment that uses appropriate tools. The most important factor a utility owner can remember is that there is no silver bullet to assess an entire system.

To solve the mystery behind Non-Revenue Water (NRW), utilities need to play detective and think like a modern day Sherlock Holmes. Pipeline operators can look for clues using deduction, engineering forensics and the latest leak detection tools designed to help find the real and apparent sources of water loss in their water networks. Real losses refer to water lost from leaks and main failures, while apparent losses come from theft and metering inaccuracies.

Problems arise because NRW often goes unnoticed until a leak surfaces or a catastrophic failure happens. Sherlock Holmes might conclude his case with “death by a thousand small cuts,” while utilities might conclude their investigation with the loss owing to “a thousand small leaks.”

Every day, billions of gallons of water are lost worldwide due to factors including leaks, water main failures, theft and metering inaccuracies. Not only does this represent a waste of this critical resource that many people cannot reliably access, but it also represents a huge loss of revenue and energy required to pump and treat the water. To that, add a loss of confidence in the utility, especially with disgruntled ratepayers asking why their water bills are so high.

Worldwide, the NRW cost to utilities is staggering

The NRW loss boggles the mind. The World Bank estimates that NRW costs utilities worldwide about US$14 billion annually. By reducing these losses by half in areas with the highest NRW, the World Bank estimates that US$2.9 billion cash would be generated, giving an additional 90 million people access to treated water.

While the NRW rate in the United States is estimated by the United States Environmental Protection Agency (EPA) in the range of 10 to 40 percent, the water loss rate in developing countries can be as high as 60 percent – owing to fewer resources available to put against water loss management programs.

Clearly, focusing leak and theft detection system-wide is the first step in a NRW-reduction strategy to mitigate problems and improve pipeline reliability.

Globally, Pure Technologies is regarded as a highly reputable service provider with the experience, expertise and technology services designed to help manage NRW projects for both small and large utilities.

Over the course of investigating more than 3,200 kilometers (2,000 miles) of pipeline, Pure’s inline leak detection services have effectively found an average of 3.5 leaks per kilometer (2.2 leaks per mile) in large-diameter water trunk mains.

Pure helps K-Water develop its leak detection program in South Korea

Pure has developed a successful NRW leak detection program with K-water, the national bulk water utility in South Korea that supplies water across the country.

Through its water system, K-Water controls everything from collection, treatment and pumping to maintenance, inspection and rehabilitation of the nation-wide pipeline system. The pipes in these critical bulk trunk mains are primarily large-diameter, and supply water to many of the smaller cities across South Korea.

In addition to supplying treated water to these small cities, many municipalities have contracted K-water to manage and maintain their water systems as they battle the challenges of ageing infrastructure buried in often mountainous terrain.

While K-water’s critical trunk mains have a very low NRW rate, usually around 2 percent, many of its clients suffer from high rates of NRW as their aging pipeline infrastructure begins to leak.

Sahara® tethered pipeline inspection system to the rescue

To address leaks and ageing systems, K-water adopted Pure’s advanced Sahara® technology, a tethered system that combines acoustic leak detection and inline video. While many utilities around the world use this tool for large-diameter leak detection, K-water instead chose to use it as a complete condition assessment tool to provide information on its pipelines as well as the accurate location of leaks.

K-water’s expert internal engineering group utilizes the Sahara video feature to assess the condition of its steel pipes by identifying defects on the pipe wall and joints.

By using this inline detection tool, K-water has been very successful in reducing water loss, saving millions of gallons of water annually.

As the K-water example points out, carrying out regular, comprehensive leak detection programs can help utilities significantly reduce water loss. Not only do these initiatives save money and improve pipeline reliability, the programs also contribute to utility confidence in promoting long term sustainable water use.

Though not quite as old as Rome’s ancient aqueduct system, the water and wastewater infrastructure operated by many North American utilities might, to some observers, appear just as antiquated.

For many pipeline operators, failures on pipelines installed decades ago are increasing in frequency, and as large-diameter pipeline assets begin to fail more frequently, the results can be more severe. This ongoing problem leaves utilities between a rock and hard place on whether to maintain or replace their assets.

Pipeline operators might do as the astute Romans did – take a step-by-step proactive approach to manage their transmission systems, enhanced today with the help of modern inline technologies.

The U.S. Environmental Protection Agency and American Society of Civil Engineers estimate the funding costs associated with buried infrastructure ranges from more than $200 billion to $1 trillion over the next 25 years. Pure Technologies is helping utilities manage their buried infrastructure through its Assess and Address® approach to pipeline management. This approach has saved clients hundreds of millions of dollars in capital replacement costs.

Assess and Address the System for Potential Problems

Conventional pipeline management allowed a pipeline to fail multiple times before replacement. While this “three strikes and you’re out” approach may work well for small-diameter distribution pipelines, it isn’t a cost-effective solution for large-diameter pipelines, especially those built without redundancy and without practical options to shut down.

A capital replacement program for large-diameter pressure pipelines not only carries a high price, but also poses significant logistical challenges, especially in urban centers. The headaches get bigger if a section of problematic pipeline runs through the downtown core and is the main source of water for a hospital or office tower.

Through the assessment of more than 8,000 miles of large-diameter pipelines, it is clear that even problematic transmission mains can be managed. In fact, Pure has found that 96 percent of pipe sections do not have any deterioration at all and are in “like new” condition, while less than 1 percent of pipe sections require immediate repair.

Better Understanding Ensures Fewer Surprises

In order to effectively manage a pipeline system, utility operators must first understand their pipeline system. Since many systems were built decades ago, the drawings are often out of date, as features have been added or removed over the years. By completing the knowledge-gathering process before attempting inspections or repairs, utility operators can avoid surprises and create a streamlined pipeline management effort.

By working with a firm that specializes in condition assessment, utility operators can gain a better understanding of their network, and create a prioritized plan for inspection or renewal.

As an example of smart collaboration, Pure Technologies has partnered with Washington Suburban Sanitary Commission (WSSC) in a multi-year program to manage approximately 145 miles of prestressed concrete cylinder pipe (PCCP) water transmission mains that serve nearly 2 million customers outside of Washington, DC. By adopting the Assess and Address model, WSSC has been able to evaluate and actively monitor the condition of its PCCP inventory instead of completing an expensive capital replacement project. To date, over 70 miles of PCCP is being safely managed for approximately 6 percent of the capital replacement cost, saving WSSC nearly $2 billion, which was the estimated capital cost of replacing the assets entirely.

Pure’s fundamental approach to pipeline management programs is to maximize the life of the existing pipeline. Maintaining an existing pipeline though proactive repair and management is in the utility’s economic interest. Our approach identifies deteriorated pipe sections, allowing for isolated repairs that extend the life of a pipeline, rather than making broad recommendations to replace the entire pipeline with capital funds.

Based on the average annual capital spending of large water utilities, it would take decades to replace large-diameter assets entirely, without factoring in the need for other capital renewal projects. Not only is this expensive and time consuming, it is also logistically challenging and disruptive to replace large sections of pipeline.

The Assess and Address Approach Involves 4 Steps

To successfully implement a pipeline management program, utilities can generally follow four key steps:

  1. Understand – Review current pipeline data, complete a risk evaluation, and develop appropriately scaled condition assessment strategies for prioritized pipelines.
  2. Assess – Execute condition assessment using a variety of tools to collect data and evaluate the data to assign condition ratings. This step includes a report of findings and recommendations on how to manage the pipeline.
  3. Address – Problematic locations identified in the condition assessment can be renewed immediately or planned for future re-inspection.
  4. Manage – After rehabilitation, the risk of failure is lower and proactive management measures should be employed to maintain a low risk.

As a result of Pure’s pipeline management programs with clients that range from small towns to major cities, utilities have seen a significant per-mile reduction in costs, while obtaining technically superior data on the real condition of their most critical pipeline assets. With such impressive numbers, it’s something ancient Roman engineers would appreciate.

Sewer pipes below a road

A critical component of Queensland Urban Utilities’ sewerage network is a series of large-diameter sewer rising mains – also known as force mains – which are responsible for transporting 50 per cent of raw sewage in the Brisbane area for treatment. The mains are made of mild steel cement-lined (MSCL) pipe and prestressed concrete pipe (PCP), of diameters ranging from 1295 to 1840 millimetres (52 to 74 inches). The reliability of these sewer rising mains are important from both a customer and environmental perspective.

Building upon previous assessments conducted by Pure Technologies’ Engineering Services, Queensland Urban Utilities sought to identify industry best practices for assessing these critical large-diameter rising mains. The goal of the assessment was to understand the current condition of the mains and identify what remedial works or condition monitoring approaches would help maintain the safe operation of the mains, while extending the life of the assets in accordance with management plans.

In consultation with Pure Technologies, a comprehensive assessment methodology was developed which included: SmartBall® leak and gas pocket detection; ground surveys to determine residual ground cover; isolation, dewatering and cleaning of the mains; CCTV and laser profiling to determine internal deterioration; valve inspections; PureEM™ inspection to determine structural deterioration of the pipe walls; internal visual inspection to confirm and further document findings; transient pressure monitoring to identify loading conditions; and an engineering assessment with rehabilitation recommendations.

PureNET Overhead

A customised EM tool was designed to assess the condition of QUU’s
steel pipe.

Field Data Collection

The inspection provided QUU with actionable information about their assets.

 

Related Topics

“Queensland Urban Utilities is keen to embrace new technologies to improve our customer service and the reliability of our water and sewerage network,” says Jonathan Farrell, Design Manager at QUU. “The technical expertise provided by Pure has allowed us to undertake an accurate condition assessment and have the appropriate data to make an informed decision on the current condition of the mains. This will allow us to plan cost-effective, timely upgrades to ensure the asset reaches its design life.”

This was a first-of-its-kind assessment in Australia applying new inspection technologies, including the customisation of a 48-detector PureEM tool, as well as a new risk assessment technique for metallic pipes. Detections from the PureEM inspection (i.e. discrete areas of structural deterioration) were validated utilising alternate electromagnetic and ultrasonic techniques, which provided supplemental condition information for the structural assessment.

Inspection and assessment work on two of these critical mains has been completed at this point. The inspection identified specific pipes along the mains with deterioration; but more importantly, the engineering assessment with structural modeling determined that less than 1 per cent of pipes are at a higher risk of failure, meaning the main is in primarily good shape. This data coupled with engineering recommendations is enabling Queensland Urban Utilities to make informed decisions on the mains, including: selective repair or replacement, condition monitoring, and operational changes (i.e. safe working pressure), all for a fraction of the capital replacement costs.

In addition, the work associated with the assessment has provided Queensland Urban Utilities with some valuable lessons learned on the safe management and operation of the mains.

 

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Cast Iron Pipes

Managing Metallic Pipelines

Pure offers a number of leading edge technology options for assessing the condition of ferrous water and wastewater mains.

Padre Dam Municipal Water District Assesses Steel Pipeline with Advanced Inline Technology

In November 2012, PDMWD wanted to assess the condition of a 1.2-mile (2-kilometer) stretch of 20-inch (500-mm) mortar-lined steel pipeline that was thought to be in poor condition and may need replacement. Before committing to the large capital project, PDMWD completed a non-destructive inline assessment.

Steel Pipes

Steel Pipe

In an article from the August 2013 Issue of Municipal Sewer and Water, the author explores how Baltimore City Public Works (BPW) is managing its again water system using Acoustic Fiber Optic Monitoring and free-flowing electromagnetic (EM) technology.

Across the United States, there are many thousands of water and wastewater utilities that serve populations less than 50,000. Although the majority of attention surrounding aging infrastructure focuses on the challenges of large utilities, these small utilities are often faced with greater challenges.

Smaller utilities often have fewer resources – both financial and personnel – devoted to managing their water and wastewater systems. At times, this can lead to the utility having  less information available about their system, such as pipe drawings, break and leak history and condition data.

Coupled with having fewer resources, small utilities often have primary mains that are non-redundant and represent the sole source of supply or collection for the population, making a leak, rupture or shutdown of any kind very disruptive.

The City of Tarpon Springs, FL serves a population slightly less than 25,000. With limited resources and a mandate to provide both reliable water supply and wastewater collection for its customers, the City decided to assess the condition of one of its primary 14-inch force mains that experienced a failure in summer 2013.

The Dixie Highway Force Main is made of 14-inch ductile iron pipe (DIP) and poly-vinyl chloride (PVC) pipe, which was installed after the failure. In summer 2014, the City decided to complete condition assessment on nearly 1 mile of the force main to identify specific areas of concern before investigating further replacement.

Since internal hydrogen sulfide corrosion is the primary cause of DIP force main failure – and was the cause in 2013 – an inline survey was completed to collect relevant condition data.

For the inspection, the City used the SmartBall® tool, which can locate leaks, gas pockets and pipe wall stress in metallic pipelines. Leaks or failures on wastewater pipelines can have a devastating effect on the environment and can lead to litigation and consent decrees. In addition, gas pockets in force mains are of significant concern as hydrogen sulfide gas within the wastewater can be converted to sulfuric acid by bacteria in the slime layer on the pipe wall, which may cause corrosion and eventual breakdown of the pipe’s exposed surface.

Leaking Pipe

The SmartBall PWA tool is removed after the 1-mile inspection.

Sahara Insertion

Staff at Tarpon Springs Water were onsite during the inspection.

While inline leak and gas pocket assessment is a well-developed approach for force main operators, the development of pipe wall assessment (PWA) technology provides a more comprehensive level of condition information – areas of the pipe wall with damage will be under more stress than areas with limited or no damage.

By identifying stress anomalies, it provides operators with a detailed report of areas that warrant a more detailed assessment or testing.

The SmartBall assessment identified no leaks and nine gas pockets along the force main. Three of the gas pockets are located along the PVC section of pipe, indicating that gas pockets re-emerged in the PVC section of pipe in less than a year after replacement. It was recommended that air release valves be installed along the force main to clear gas pockets.

In addition, the PWA survey identified six areas that indicated stress within the pipe wall. One of the stress anomalies corresponds with a transition from buried pipe to exposed pipe, and therefore is caused by the change in load. The remaining five PWA anomalies do not correspond to any known features and could represent pipe degradation. The City during the insertion of the air release valves will be performing some field validation of these pipes.

By assessing the entire force main in advance of replacement, the City of Tarpon Springs is now able to make more informed decisions about its critical asset while avoiding the costly and mostly unnecessary strategy of replacement of the entire force main length. This mentality is an excellent example for other small utilities that are looking for ways to manage aging critical infrastructure, since replacing assets is very expensive within limited capital budgets.

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SmartBall Pipe Wall Assessment

Pipeline Leak Detection Systems

Highly accurate inline leak detection systems that can detect leaks and gas pockets in operational pipelines. These systems are used primarily on larger diameter water and wastewater transmission mains of all materials as well as oil & gas pipelines.

Frankfort Electric and Water Plant Board Verifies Distress on Ductile Iron Pipe Using Electromagnetics

In June 2013, FEWPB agreed to utilize an electromagnetic (EM) assessment technology on 700 feet of 1974 era DIP after the successful assessment of almost five miles of its prestressed concrete cylinder pipe (PCCP). The 700-foot section of 48-inch DIP runs directly from one of FEWPB’s water treatment plants and connects with the primary transmission main.

Ductile Iron Pipe

Ductile Iron Pipe (DIP)

Introduced into the U.S. marketplace in 1955, ductile iron pipe (DIP) is pressure pipe commonly used for potable water and sewage distribution. The predominant wall material is ductile iron, a spheroidized graphite cast iron, although an internal cement mortar lining usually serves to inhibit corrosion from the fluid being distributed, and various types of external coating are used to inhibit corrosion from the environment.

Abstract

Comprehensive condition assessment of wastewater force mains provides significant challenges to owners/operators of collection systems as the ability to shut down or expose the pipeline for a thorough inspection is often impractical due to operational and/or financial considerations. Traditional gravity sewer inspection techniques (i.e. visual-based technologies) do not always transfer easily to their wastewater pressure pipe counterparts and visual assessments do not provide the structural condition of force mains – something that is critical in determining the true pipe condition. Therefore, a different set of inspection tools and assessment techniques is required for force mains.

The most effective strategy to safely manage a force main inventory is to implement a risk-based approach for any data collection, inspection, condition assessment, and management techniques. Using asset risk to guide the management strategies, an owner/operator can ensure they are implementing the right approach, at the right time, with the lowest financial impact. While recent advances in force main inspection technologies, assessment techniques, and repair/rehabilitation methods now allow for substantial extension of existing asset service life, a risk-based approach to their implementation will ensure resources are focused on the correct pipelines. The goal should always be to focus the proper resources in managing the asset while safely getting the most service life out of the force main.

Authors

  • Travis B. Wagner, Pure Technologies Ltd., Columbia, MD, USA
  • Jennifer Steffens, Pure Technologies Ltd., Atlanta, GA, USA

For water service providers in Texas, providing customers with consistent, reliable access to water is crucial, particularly in the summer months when dry conditions impact the water supply.

In order to ensure that residents receive consistent water supply, the City of Irving and a partnering agency have collaborated in times of need to supply the other with water.

In one specific instance, the City of Irving was able to keep customers of the partnering agency supplied with water from one of its 48-inch transmission mains. The combined effort between the utilities showed excellent organizational cooperation to achieve the most important goal for any utility – finding a way to provide consistent service.

In January 2014, the two agencies teamed up again, this time to assess the critical 48-inch Jamison Main that links the two utilities. The transmission main was constructed in 1955 and is made up primarily of Bar-Wrapped Concrete Cylinder Pipe (BWP). Since its construction, however, the main has had modifications: in 1965 and 1968 sections of Prestressed Concrete Cylinder Pipe (PCCP) were added to accommodate the construction of Texas Stadium, and in 2009, another section of PCCP was added during the reconstruction of Loop 12 Highway.

The Difference Between PCCP and BWP

While BWP and PCCP look similar in cross-section, the pipe materials deteriorate in different ways and therefore are assessed differently.

For BWP, it is important for operators to identify and locate corrosion on the steel cylinder, since it is the main structural component and the bars are made with mild steel and are wrapped under less tension than PCCP; BWP essentially behaves like a mortar-lined and coated steel pipe.

PCCP is a concrete pipe that remains under compression because of the prestressing wires, with the thin-gauge steel cylinder acting as a water barrier. The high strength steel wire in PCCP is smaller in diameter and wrapped under higher tension, therefore corrosion makes it quite vulnerable to breakage.

Electromagnetic inspection tool

Electromagnetic inspection tool

Robotic tool insertion

Pure Technologies staff insert the robotic tool for assessment

As the prestressing wires in PCCP begin to break, the pipe becomes weaker and is more likely to fail catastrophically. It is important to locate and quantify the amount of broken wires in PCCP as they are the main structural component.

Because of the differences, the two materials are assessed using electromagnetic (EM) technology that identifies different signs of deterioration in each pipe.

In BWP, inspections identify both the presence of broken bars – which could indicate corrosion on the cylinder – and broad areas of corrosion on the cylinder itself. This approach allows operators to renew pipe sections with an undesirable amount of corrosion that could lead to pipe failure.

In PCCP, EM technology locates and quantifies the amount of broken wires. This method is extremely effective in identifying pipe sections that are suitable for renewal once the number of wire breaks passes a certain limit.

The Condition Assessment Program

For the Jamison Water Transmission Main assessment, the SmartBall® leak detection and PureRobotics® platforms were used to identify deterioration on both the primary pipe material, BWP, and the added sections of PCCP.

Completing a leak detection survey is an important aspect of a condition assessment project, since leaks are often a preliminary indication of a potential failure location. Pre-screening is particularly important in in BWP, since the steel cylinder is the main structural component and the pipe behaves similarly to a mortar-lined and coated steel pipe.

The leak detection survey identified one acoustic anomaly associated with a leak in 2.7 miles of inspection. The screening of the pipeline helps determine the baseline condition of the asset.

The PureRobotics platform was used for the structural assessment portion of the project. The tool is equipped with PureEM™ technology, which can identify distress on both pipe BWP and PCCP, but also features CCTV and above-ground tracking. By completing a structural assessment, damaged areas of the pipe can be targeted for selective renewal.

The Condition Assessment Program

In addition to gaining a valuable baseline condition of the transmission main, the assessment provided both utilities with more information about the location of additions to the critical transmission main.

The CCTV and line-locating feature were used to identify the exact location of two unknown manholes, which in turn were used as additional tracking locations. With more tracking locations during inline inspection, areas of distress can be more accurately located. The CCTV inspection also identified the location of a 48-inch gate valve and 90-degree bends.

Another challenge surrounding this main was accurate mapping of the sections that were added on after the original construction. Additions or alterations to existing pipelines can sometimes lead to inaccurate drawings. By tracking the tethered robotics tool above the ground using a manned sensor, Irving and its partnering agency were able to map out the relocated portions of the pipeline. This provides valuable information for future maintenance, assessment and renewal programs.

Through close collaboration, these two service providers were able to effectively manage a shared asset with the goal of preventing disruptive and expensive pipe failures. The information gained from the structural assessment will allow for the implementation of a cost-effective long-term pipeline management plan and effectively defer the replacement of the pipeline for the foreseeable future.

 

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Case Study

Case Study: Trinity River Authority of Texas

After completing leak detection and structural condition assessment on 8.5 miles of PCCP and Bar-Wrapped Pipe, Trinity River Authority verified the results of inspection, finding three distressed pipe sections.

Technical Paper

Failure Risk of Bar-Wrapped Pipe with Broken Bars and Corroded Cylinder

This study investigates the behavior of a deteriorating BWP under various levels of distress and various internal pressures. The results based on a 24-inch pipe transmission main, are used to define criteria to evaluate the performance of a damaged BWP. Based upon the finite element results obtained in this study, suggestions for future work are presented and discussed.

To proactively address its large-diameter Prestressed Concrete Cylinder Pipe (PCCP) for deterioration, Tampa Bay Water (TBW) completed a leak and gas pocket survey and electromagnetic (EM) condition assessment of the South-Central Hillsborough Regional Wellfield Transmission Main in April 2013. The results of the assessment were verified in 2014 to determine the remaining useful life of the pipeline, which is responsible for delivering 10 percent of TBW’s 24 million gallons of raw water per day.

Based on the EM inspection, only 0.5 percent (11 of 2,177) of pipe sections contained varying levels of distress; subsequent structural and finite element analysis determined that only a fraction of the distressed pipes warranted further consideration. In addition to the structural assessment, the leak and gas pocket survey identified only one small leak.

The results show the critical transmission main is in excellent condition and can be safely managed despite being nearly 30-years-old. Some PCCP users throughout the United States have experienced major failures as their assets approach 40 years of operation.

TBW maintains a large pipeline network that serves the Tampa Bay and St. Petersburg metropolitan area and includes approximately 80 miles of PCCP. The pipeline inspections were completed on 8 miles of 42-, 48- and 54-inch PCCP that convey wellfield supply to the Lithia Water Treatment Facility.

For the leak and gas pocket survey, SmartBall® technology was used as a forerunner for the EM condition assessment and provided TBW with an initial condition of the pipeline.

Early identification and repair of leaks can reduce Non-Revenue Water (NRW), but also helps determine the baseline condition of a pipeline, since leaks can be an indication that a pipeline might fail. In addition, locating and eliminating gas pockets reduces pressure on the pumps that are attempting to push water past a pocket. As pockets grow in size, they can significantly affect the flow of water and capacity of the pipeline if not released.

After the prescreening survey, TBW completed an EM inspection using PipeDiver®, a free-flowing EM tool that is able to accurately locate and quantify broken wire wraps in PCCP. The wire wraps in PCCP act as the main structural component; broken wraps are the main indication that this type of pipe will eventually fail.

TBW’s asset management program allowed them to prioritize and take the first steps in determining the remaining useful life of a critical asset. This will lead to more informed decision-making for the future management of this main through reinspection, monitoring or renewal.

 

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Technical Paper

Beyond the Wires: A Sustainable Approach to Prestressed Concrete Cylinder Pipe Management

While evaluating wire breaks are an important part of PCCP management, it is important to acknowledge additional factors beyond wire breaks. By acknowledging additional condition factors, limitations of wire break assessment, and considering other rehabilitation approaches, there may be a more sustainable PCCP management approach (or combination of approaches).

Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Free-Swimming Pipeline Inspection

PipeDiver® – Free-Swimming Pipeline Inspection

Specifically designed for structural assessment of Prestressed Concrete Cylinder Pipe (PCCP) lines that are live or can’t be taken out of service due to a lack of redundancy or operational constraints.

TRA Verification

Commercial introduction of ductile iron pipe (DIP) began in the mid-1950s and was established as the most frequently selected material of choice for ferrous pressure pipe by the early 1970s. Due to the widespread use of DIP during a large expansion of pipeline infrastructure in the 1970s, there are many thousands of miles of pressurized DIP in operation today.

Water and wastewater utilities across the United States face a major funding gap related to buried pipeline infrastructure – the U.S. Environmental Protection Agency (EPA) estimates the difference between what is needed for infrastructure renewal, the majority of which is associated with buried pipe, and what utilities can afford to spend is between US$200 billion and $1 trillion over the next 25 years.

Like most of our buried infrastructure, this large ductile iron pipe (DIP) inventory has not been proactively managed since installation. This is primarily because many pipeline owners across the United States have had few financially-viable pipeline management options available, thereby leading to an operate until failure approach. Typically, once several failures occur along one of these pipelines, they are replaced without truly assessing the root cause of failure.

Although this run to failure and replacement approach is commonly applied, it often leads to two unnecessary outcomes. First, emergency responses to failures often have high costs for a pipeline owner and are also degrading public confidence in the service. In fact, the Water Research Foundation reports that small-diameter water main failures cost approximately US$10,000 for direct and social costs while large-diameter failures average US$1.7 million in direct costs alone.

Secondly, data from pipeline replacement programs throughout North America indicate that 70–90 percent of the pipe being replaced has remaining useful life. These two pieces of information lead to a simple conclusion – pipeline owners need a better management strategy to maximize operational and capital budgets by optimizing the life of these critical assets.

PureNET Overhead

FEWPB and Pure Technologies used an electromagnetic tool to assess the ductile iron pipe.

Field Data Collection

The inspection identified one pipe section with corrosion.

To do this, an owner needs to determine what assets they have, where they are, and how much life it has left. This can then drive sound, defensible decisions on the long-term management strategies for the pipelines. Part of this management strategy should be to implement a comprehensive condition assessment strategy locate, inventory, and assess the condition of the pipeline.

Pipe distress is related to localized problems, meaning pipelines rarely – if ever – fail systematically across their entire length. When a pipe fails, it is usually due to localized damage relating to internal or external corrosion, excessive loading, unexpected soil conditions, and design, manufacturing, or construction defects. This means that a near-failing pipe is likely adjacent to pipes that are in like-new condition.

In fact, data from condition assessment programs throughout North America shows that less than 5 percent of pipeline alignments have any distress while even less (less than 1 percent) require repair or replacement. Therefore, the ability to identify these isolated areas of distress is critical for owners in not only preventing pipe failures but also avoiding the expensive and unnecessary capital replacement of a pipeline with remaining life.

Current condition assessment technologies available to owners of metallic pipelines allow for the identification of these localized areas of distress across for full pipeline alignments. One example of this is a project recently completed for the Frankfort Electric and Water Plant Board (FEWPB).

Frankfort Assesses Ductile Iron Pipeline

In June 2013, FEWPB agreed to utilize an electromagnetic (EM) assessment technology on 700 feet of 1974 era DIP after the successful assessment of almost five miles of its prestressed concrete cylinder pipe (PCCP). The 700-foot section of 48-inch DIP runs directly from one of FEWPB’s water treatment plants and connects with the primary transmission main.

To identify distress along the DIP transmission main, FEWPB and Pure Technologies used a manned EM tool with 24 detectors to collect full circumferential data of the pipe wall. The tool uses PureEM™ technology and can accurately identify broad areas of corrosion in metallic pipes, which is the typical failure mode for DIP.

While the PureEM tool provides the owner with lower resolution than available high-resolution tools, it is a more operationally friendly technology deployment as it is not a full diameter device (as with the high resolution tools). Additionally, PureEM can be implemented via manned, robotic, or free-swimming deployment methods providing operational flexibility that was previously unavailable.

One Pipe Identified for Further Investigation

For FEWPB, the 700-foot inspection identified one pipe section with an anomaly representative of distress. Based on the assessment, FEWPB decided to excavate the pipe and validate the anomaly. Once uncovered, it was found that the section was resting on a damaged section of Reinforced Concrete Pipe (RCP). The damaged RCP section had exposed reinforcing steel, which led to visible galvanic corrosion on the ductile iron pipe section. The location of the external corrosion closely matched the location of the anomaly in the data.

Ultrasonic testing was then completed for the exposed pipe (including the anomalous area). The average median thickness of the non-anomalous pipe wall was 0.69 inches, which corresponds to Class 52 DIP, while the minimum thickness found in the anomalous areas was 0.45 inches, indicating up to 35 percent wall loss.

FEWPB completed its own evaluation of the structural implications of the wall loss and used determined that the pipeline was in serviceable condition under standard operating conditions. As a precaution FEWPB decided to coat the pipe with asphaltic coating and install a repair sleeve over the damaged area. Through the implementation of a proactive pipeline management strategy by using condition assessment , FEWPB was able to increase their confidence in the reliability of the asset, lower risk of continued operation, as well as defer costly (and unnecessary) operational or capital expenditures for the rehabilitation/replacement of the pipeline.

 

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Cast Iron Pipes

Managing Metallic Pipelines

Pure offers a number of leading edge technology options for assessing the condition of ferrous water and wastewater mains.

Case Study

City of Tarpon Springs Assesses Critical Ductile Iron Force Main

The City of Tarpon Springs, FL serves a population slightly less than 25,000. With limited resources and a mandate to provide both reliable water supply and wastewater collection for its customers, the City decided to assess the condition of one of its primary 14-inch ductile iron force mains that experienced a failure in summer 2013.

Ductile Iron Pipe

Ductile Iron Pipe (DIP)

Introduced into the U.S. marketplace in 1955, ductile iron pipe (DIP) is pressure pipe commonly used for potable water and sewage distribution. The predominant wall material is ductile iron, a spheroidized graphite cast iron, although an internal cement mortar lining usually serves to inhibit corrosion from the fluid being distributed, and various types of external coating are used to inhibit corrosion from the environment.

After spending eight years assessing the condition of and monitoring 77 miles of 48-inch and larger PCCP with a variety of methods, WSSC has shifted its focus to 68 miles of 36- and 42-inch mains. Many of these assets have been in the ground for decades and have never been inspected for structural deterioration.

To assess the mains, WSSC is using PureRobotics™ equipped with electromagnetic (EM) sensors. The tool is also equipped with high-definition closed-circuit television (HD-CCTV), which allows WSSC to identify cracks of the inner concrete core and determine joint condition.

WSSC recently produced a video to demonstrate how the tool works and its role within the overall PCCP assessment program.

How the Technologies Work

The EM sensors on the robotic tool identify the quantity and location of broken wire wraps in PCCP pipelines. The wire wraps in PCCP are the main structural component – as wraps begin to deteriorate and break, the pipe section becomes weaker and more likely to fail catastrophically.

By identifying broken wire wraps, WSSC is able to repair or replace specific pipe sections when they reach a wire break limit. The robotics tool used by WSSC also has an inertial mapping unit, which allows damaged pipes to be located with very close location accuracy, usually within 3 feet.

After acquiring a baseline condition of its transmission mains, WSSC plans to install an Acoustic Fiber Optic (AFO) monitoring system to track ongoing deterioration. The AFO system records the sounds of wire wraps snapping, which allows WSSC to intervene and replace a pipe section when too many wire wraps snap in a short span – which indicates accelerating distress – or the amount wire breaks reaches a certain level.

WSSC’s PCCP program is one of the largest and most advanced infrastructure management programs in the industry; however the cost of assessing, monitoring and managing its most critical assets is roughly 6 percent of the $2-billion capital replacement estimates.

To date, WSSC’s inspections have shown that about 95 percent of pipes are in “like new” condition and less than 2 percent require any immediate rehabilitation or replacement. By identifying select distressed areas, WSSC was able to avoid a full replacement program and avoided massive capital replacement costs by rehabilitating the identified sections.

 

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

WSSC Logo

Washington Suburban Sanitary Commission Avoids Critical Failure Through the use of Fiber Optic Monitoring

To prevent critical water main failures, the Washington Suburban Sanitary Commission (WSSC) has installed acoustic fiber optic cable in many of its Prestressed Concrete Cylinder Pipe (PCCP) transmission mains. This technology has prevented a number of major pipeline failures, most recently in Prince George’s County on a 54-inch transmission main.

PureRobotics™ – Pipeline Inspection

Robotic Pipeline Inspection

PureRobotics uses powerful modular robotic pipeline inspection systems that can be configured to inspect virtually any pipe application 12-inches (30.5 centimeters) and larger.

The most pressing issue surrounding water and wastewater assets is with aging pipelines. While there are many of miles of pipes beneath the ground, the most critical are large-diameter water and wastewater mains, which are often the most valuable asset a municipality owns. These pipelines provide critical services for communities and are beginning to leak and rupture more frequently; not only does this disrupt these vital services but also costs municipalities billions of dollars annually.

While the cost of replacement is high, it is less expensive than allowing these assets to operate until failure. However, for many utilities, it doesn’t need to be all or nothing – the majority of water and wastewater systems can be safely and efficiently managed using a risk-based condition assessment approach.

The primary misconception that many operators have is that the majority of aging pipelines need replacement. This thought process often comes after a critical large-diameter failure, which can cause a negative public perception that the majority of pipe in a system is in near-failing or poor condition. Replacing large sections of pipe is not only extremely expensive – the average cost to replace one mile of pipe is US$1.8 million – but is also extremely difficult logistically, especially as urbanization continues.

Fortunately for utilities, the vast majority of pipelines can remain operational well beyond their intended design life, provided they are managed properly.

Pipe distress is a localized problem, meaning that one pipe section that is badly deteriorated or has failed could be neighbored by pipes that have virtually no damage at all. This is because local factors – such as load, soil conditions, operating conditions and installation – affect how quickly a pipe deteriorates. Through more than 8,000 miles of pressure pipe assessment, Pure Technologies has found that only 4 percent of pipe has some level of distress while less than 1 percent requires immediate renewal.

By managing assets, operators can combine the best of each approach – renewing large-diameter pipe with isolated damage and replacing lower cost assets – to achieve the highest return on investment. Proactive utilities have realized that when implementing condition assessment for a system of pipelines, a risk-based approach is an effective way to ensure resources are invested in an intelligent, defensible and repeatable manner that maximizes the benefit of a program.

Engineers analysing data

Risk-based condition assessment combines state-of-the-art technologies with expert engineering analysis.

Worker performing assessment

Condition assessment can help operators identify specific pipe sections that require renewal.

Defining Risk

To determine risk, operators must measure the probability and consequence of uncertain future events – in this case, pipe failure. This can be determined by multiplying two factors, consequence and likelihood of failure. Consequence of Failure (COF) refers to the damage a failure would cause based on factors such as its location, the amount of users it supplies and its size and operating pressure. Likelihood of Failure (LOF) refers to the probability of a failure occurring based on factors such as age, pipe material, soil conditions, operating pressure, failure history, among others.

Generally, the Consequence of Failure is well-defined by the potential damage a pipeline failure would impose on the surrounding environment and is generally fairly static, or, once defined it is unlikely going to change rapidly. With this in mind the key to managing risk – or the uncertainty that a pipeline could fail – is in understanding the likelihood of failure. This can be achieved by quantifying the physical condition of the pipeline and understanding and quantifying the factors that affect the potential for deterioration of the assets.

To determine the physical condition of an asset, there are a number of technologies that can identify both the presence and level of distress. When determining which to use for each asset, risk is the most important factor. For high-risk assets, a detailed assessment is needed, while lower risk assets may warrant a lower-resolution screening or no assessment at all, as the cost of assessment would outweigh the benefit of replacing the asset entirely.

Naturally, as the resolution increases on an inspection technology, so does the certainty it provides to the operator, as well as the cost of the project. However, when deciding how to best assess critical pipeline assets, a simple comparison to how people should handle a significant health concern draws an important parallel for operators of large-diameter pipelines.

For example, if a person gets chest pain when they exercise – a serious problem – there are different levels of medical certainty they can attain. Going online to search medical journals or websites and completing a self-diagnosis is a free option, but it provides little certainty of long term health. A second option is visiting a general practitioner. He will be able to decide whether or not something is wrong, but won’t be able to diagnose it specifically and will recommend further investigation. To be confident in the results, the person would need to visit a heart specialist and complete specific tests.

While each of these options gets more detailed and expensive, the risk of leaving a heart problem untreated outweighs the cost of a detailed evaluation from a specialist. Utility managers should treat their critical large-diameter pipeline assets the same way a significant health problem, as the risk of uncertainty far outweighs the cost of being sure.

As municipal operators continue to grapple with aging water and wastewater infrastructure, identifying and managing risk should be an important consideration in the development of pipeline management, renewal and replacement programs.

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Pipeline Inspection and Condition Assessment Services

Pipeline Inspection and Condition Assessment Services

We provide water and wastewater organizations a comprehensive suite of technologies that provide actionable pipeline information to better understand the condition of their pipe.

Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

To protect a thriving economy, Californian water utilities require a reliable and predictable supply of clean water; any water lost through leaks not only threatens the ability to provide adequate service, but also represents the waste of a scarce resource.

In order to ensure reliable service delivery and reduce Non-Revenue Water (NRW) – which can be defined as water that is produced for consumption and lost before it reaches the customer – two Californian utilities completed leak detection surveys on their critical water transmission mains in December 2013, while a third utility assessed a force main with a suspected leak.

While reducing NRW can be challenging, one of the most effective methods in reduction is having a well-developed leak detection program for both small- and large-diameter water mains. For large-diameter pipes, the most effective method of identifying leaks is through the use of inline leak detection. This method brings the leak detection sensor directly to the source of the leak, which provides the highest level of accuracy.

Accurately locating and repairing leaks on large-diameter mains is the best way to reduce NRW through leak detection, as almost 50 percent of the water lost through leaks is through large-diameter assets. Identifying leaks also increases service reliability and reduces the likelihood of a pipeline failure, as the presence of leaks is often a preliminary indication of a failure location.

In December 2013, the Los Angeles Department of Water and Power (LADWP) completed an inline leak detection survey on 8 miles of the 45-mile Second Los Angeles Aqueduct, which is made of 76-inch mortar-lined steel.

Identifying leaks on metallic pipe materials is particularly important for water utilities, since leakage is a main indicator that metallic pipes will eventually fail. LADWP’s inspection using SmartBall® leak detection confirmed that this section of the aqueduct is leak-free.

Although addressing NRW is a major priority for utilities, operators of wastewater force mains should also be concerned with leakage. Leaks or failures on wastewater pipelines can have a devastating effect on the environment and can lead to litigation and consent decrees. In addition, gas pockets in force mains are of significant concern as hydrogen sulfide gas within the wastewater can be converted to sulfuric acid by bacteria in the slime layer on the pipe wall, which may cause corrosion and eventual breakdown of the pipe’s exposed surface.

In order to conduct a leak and gas pocket screen on an 18-inch force main, the Vallejo Sanitation and Flood Control District completed a 1.3-mile survey using SmartBall technology. The inspection identified three acoustic anomalies that were associated with pockets of trapped gas.

Through the inline assessment of this force main, the District was able to identify areas of potential concern, which will focus resources and guide future investigations.

Pipeline leak detection systems

Pipeline Leak Detection Systems

Highly accurate inline leak detection systems that can detect leaks and gas pockets in operational pipelines. These systems are used primarily on larger diameter water and wastewater transmission mains of all materials as well as oil & gas pipelines.

Smartball- Leak and Gas Pocket Detention

SmartBall® – Leak Detection for Water Trunk Mains

SmartBall® is an innovative free-swimming inline leak detection technology designed to operate in a live water mains.

Across the United States, there are thousands of miles of water and wastewater pipes buried beneath communities. These pipes come in a variety of materials and sizes, but all provide necessary services to customers across the country.

In recent years, several industry studies have warned that a large majority of these assets are aging and reaching the end of their designed lifespan. Although this is true, it is often prudent for municipalities to manage their assets – especially their large-diameter pipelines – in favor of replacement.

Replacement is expensive – industry experts estimate that the costs could reach $1 trillion over the next three decades. But beyond this massive expense are the unassailable logistical challenges of replacing thousands of miles of pipe.

Fortunately for municipalities, some pipe materials that make up the nation’s infrastructure have well-developed assessment methods that allow operators to determine the location of deterioration so that pipes can be renewed. Pipe deterioration is often due to localized problems – such as soil, loading and operating conditions – meaning pipelines do not fail systematically across their entire length and can often be effectively managed.

Unfortunately for some municipalities that own large-diameter metallic pipe, like Padre Dam Municipal Water District (PDMWD), the technologies available for assessing its condition have only recently been developed.

In November 2012, PDMWD wanted to assess the condition of a 1.2-mile (2-kilometer) stretch of 20-inch (500-mm) mortar-lined steel pipeline that was thought to be in poor condition and may need replacement. Before committing to the large capital project, PDMWD completed a non-destructive inline assessment using Mini PipeDiver®, a free flowing tool that can determine the baseline condition of metallic pipes.

The tool is equipped with PureEM™ technology and can detect broad areas of corrosion on metallic pipelines. While its resolution is not as high as other metallic inspection platforms, such as Magnetic Flux Leakage which can identify very small defects, PureEM is capable of detecting areas of corrosion that could lead to near-term pipe failure. It is also able to assess long distances in a single deployment, making it ideal for pipelines that cannot be removed from service.

Pure Technologies staff calibrate the Mini PipeDiver tool prior to inspection.

Pure Technologies staff calibrate the Mini PipeDiver tool prior to inspection.

Staff extract the PipeDiver tool from the pipeline.

Staff extract the PipeDiver tool from the pipeline.

In total, the inspection identified six pipes with signals consistent with localized circumferential anomalies and 15 pipe sections showed signal shifts indicative of a pipe class change.

Starting in February 2013, PDMWD began validating the results of the inspection by excavating the six pipes with circumferential anomaly signals. All six anomalies were confirmed to have some level of defect including:

  • Unknown concrete encasement covering a 2-foot longitudinal weld at a pipe joint; this pipe was damaged and repaired during the installation phase without proper documentation
  • Damaged mortar lining and steel cylinder after the pipe was installed on a rock
  • Localized cylinder and wire mesh corrosion
  • Excessive wire wraps caused by a manufacturing defect

While the six anomalies represented different forms of damage, the information collected using PipeDiver was accurately verified and was very useful for PDMWD. In addition, the anomalies that indicate a pipe class shift provide the District with valuable information about their system that was previously unknown.

Based on the results of the condition assessment, PDMWD determined that a large replacement or renewal project was unnecessary and could be deferred. This allows the District to be confident in the condition of this pipeline while maintaining safe and reliable service for its end-users.

PipeDiver® – Free-Swimming Pipeline Inspection

Specifically designed for structural assessment of Prestressed Concrete Cylinder Pipe (PCCP) lines that are live or can’t be taken out of service due to a lack of redundancy or operational constraints.

Managing Metallic Pipelines

Pure offers a number of leading edge technology options for assessing the condition of ferrous water and wastewater mains.

Cobb County-Marietta Water Authority (CCMWA) is the second largest drinking water supplier in Georgia, providing vital service to nearly 800,000 people through twelve wholesale customers. With two award-winning water treatment plants and over 200 miles of large-diameter transmission mains, CCMWA can deliver up to 158 million gallons per day. Two of CCMWA’s key objectives are to be financially viable and to reduce vulnerabilities by improving redundancy and implementing a comprehensive asset management program.

However, across the United States critical infrastructure is aging, causing utilities to see an increased number of water pipe failures. While these failures occur most commonly on small pipes – causing only minor disruptions – large-diameter mains do fail, resulting in major delays and enormous repair bills.

A large portion of CCMWA’s large-diameter pipeline inventory is made up of Prestressed Concrete Cylinder Pipe (PCCP). In order to successfully manage PCCP, the water industry has widely adopted the use of condition assessment techniques, which have a proven track record of identifying and averting PCCP failures. PCCP owners and operators continue to use these condition assessment methodologies combined with sound engineering analysis to effectively and safely manage their critical assets.

Cobb County’s Program

In 2012, CCMWA was in a similar situation to many predominant PCCP users; past failures on these critical assets had led to the decision to replace the majority of PCCP assets to avoid the risk of future failures. However, it was determined that replacing large sections of pipeline was not financially or logistically feasible.

Large-scale replacement programs are also unnecessary based on industry research, which confirms that pipe deterioration is not uniform or systematic. Specifically, electromagnetic inspection data (which identifies both the quantity and location of broken prestressing wires – the primary structural component of PCCP) collected by Pure Technologies over more than a decade indicates that less than 4 percent of pipe sections inspected have any level of wire break damage and less than 1 percent require repair – regardless of when it was manufactured.

SmartBall tool extraction

The SmartBall tool is retrieved from the extraction point.

PipeDiver retrieval

Staff remove the PipeDiver tool after the non-destructive assessment.

Therefore, by making the decision to replace entire alignments of PCCP, owners typically remove a majority of pipeline assets that are in like-new condition. A financial evaluation based on the cost of capital replacements compared with PCCP management (inspection, repair, re-inspection, and repairs) for the 48-inch diameter PCCP in CCMWA’s inventory indicates that the pipelines can be managed for approximately 10 percent of the capital replacement costs when extended over 25 years using a net present value calculation (Figure 1).

Capital Replacement vs Condition Assessment

Figure 1: Financial Evaluation of Capital Replacement vs Condition Assessment

Following a repair on a 30- and 42-inch Raw Water Line in 2012, CCMWA decided to manage its critical PCCP assets using condition assessment and engineering analysis as a proactive management strategy. In 2013, CCMWA completed its first full inline condition assessment to identify structural deterioration on its PCCP. The project focused on the 30- and 42-inch main that had previously been found to have defective joints and a deteriorating pipe wall to determine its remaining useful life.

The Inspection Program

The assessment featured two inspections – a leak and gas pocket survey and inline electromagnetic (EM) inspection – on roughly four miles of the 30- and 42-inch PCCP Raw Water Line. The subject pipeline acts as a redundant supply line from Lake Acworth to the Wyckoff Water Treatment Plant. The project also included engineering evaluations including structural analysis and remaining useful life evaluations to make management and renewal recommendations. For the prescreening survey, CCMWA used SmartBall® leak detection, a free-flowing tool that identifies the acoustic anomalies associated with leaks and gas pockets in large-diameter pipelines. Completing a prescreening leak and gas pocket survey is a prudent approach for operators of any pipe material, since leaks are often a preliminary indication of a failure location. For PCCP, leaks are usually located near the pipe joint, which is also a common failure area on PCCP. However, the inspection did not identify any leaks or pockets of trapped gas. For the more detailed structural evaluation, the PipeDiver® electromagnetic (EM) inspection platform was used. The tool uses electromagnetics to identify broken prestressing wires, which are the primary structural component in PCCP. As sections of PCCP begin to deteriorate, the prestressing wires begin to break, which weakens the pipe and makes it more likely to fail. Identifying broken wires is the most effective way of determining the condition of and preventing failures in PCCP. By completing an EM inspection on the PipeDiver platform, CCMWA was able to determine the baseline condition of the pipeline while it remained in service – a major benefit for operators who cannot remove mains from service to complete internal inspection.

The Results

For CCMWA, the inspection identified ten pipe segments amounting to less than 1 percent of the pipeline with evidence of broken prestressing wire wraps. On average, PCCP inspections across the country indicate that approximately 4 percent of the pipe segments have any level of damage. This confirms that the majority of CCMWA’s PCCP inventory is in good condition, with only a small number of pipe sections in need of immediate renewal. However, locating and renewing even one pipe section can help utilities maintain reliable service and avoid an expensive pipe failure. Beyond the prescreening and structural inspections, CCMWA was able to identify limitations in its potable water system through the planning portion of the project. The inspected pipeline is a redundant line which carries raw water to the Wyckoff Treatment Plant; the primary supply line to the plant is a 60-inch line. In order to ensure that the main was being operated safely within its limits, a hydraulic study was completed. This study found that the 30-inch section of the pipeline was incapable of supplying the treatment plant’s required operating flow rate while maintaining a safe operating pressure within the system. Operating the pipeline under the required pressures places the main at a higher risk of failure in the event that the primary raw water line is taken out of service. Based on the study, it was recommended that the approximately 1 mile of 30-inch PCCP be replaced to handle existing and future operating condition requirements of the treatment plant. This discovery allowed CCMWA to make defensible decisions about their 30-inch PCCP main and pumping station while contributing to the prevention of future pipe failures. By upgrading the 30-inch section of the pipeline, the raw water pipeline will remain a safe redundancy line for the main 60-inch line. By managing its PCCP assets using condition assessment, it has also been determined that less than 1 percent of pipe sections on the assessed main have any indication of wire break damage, which is consistent with industry standards. Additionally, the prescreening survey showed that there are no leaks or gas pockets that require maintenance. The results from the inspections will allow CCMWA to cost-effectively manage its PCCP assets in favor of completing a large-scale replacement.

 

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Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Pipeline leak detection systems

Pipeline Leak Detection Systems

Highly accurate inline leak detection systems that can detect leaks and gas pockets in operational pipelines. These systems are used primarily on larger diameter water and wastewater transmission mains of all materials as well as oil & gas pipelines.

Free-Swimming Pipeline Inspection

PipeDiver® – Free-Swimming Pipeline Inspection

Specifically designed for structural assessment of Prestressed Concrete Cylinder Pipe (PCCP) lines that are live or can’t be taken out of service due to a lack of redundancy or operational constraints.

TRA Verification
To supply roughly 500,000 people from eight different municipalities with treated water, the Lake Huron Primary Water Supply System (LHPWSS) operates a major 1200-mm (48-inch) Prestressed Concrete Cylinder Pipe (PCCP) transmission main that spans 47 kilometers (29 miles).

After four failures on ‘Pipeline A’ in 2012, 2010, 1988 and 1983, LHPWSS began taking a proactive approach in managing its most critical pipeline through a technology-driven management program. This includes regular inspection of the transmission main to identify specific pipe sections that have distress and are at risk of failure.
In addition to proactively managing its infrastructure, LHPWSS is also twinning the transmission main to provide redundancy in the event that Pipeline A needs to be shut down.

After a full inspection of Pipeline A in November 2012, LHPWSS assessed 6.5 kilometers (4 miles) of PCCP along the twinned ‘Pipeline B’ in December 2013 using the PipeDiver® platform. Pipeline B currently spans 28.5 kilometers (17.7 miles) and features both PCCP and Steel pipe.

The PipeDiver tool is an electromagnetic (EM) platform that operates while a pipeline remains in service. EM inspections of PCCP pipelines identify the quantity and location of broken wire wraps, which are the main structural component in PCCP. As these wraps begin to deteriorate and break, the pipe section becomes weaker and more likely to fail catastrophically.

Worker inside a pipe
Staff extracting the PipeDiver® tool

Pure’s staff extract the PipeDiver® tool from LHPWSS’s Pipeline B.

LHPWSS’s inspection of Pipeline B was also the first use of video on the PipeDiver platform. Through the video application, LHPWSS was able to see inside the pipe under live operating conditions. The use of video during inspection provides additional information to use in conjunction with the electromagnetic data.

While the full results of the Pipeline B inspection are not finalized, the inspection demonstrates LHPWSS’s commitment to preventing transmission main failures and providing reliable water service.

This approach has been effective for LHPWSS in the past, as the 2012 inspection of Pipeline A identified only 58 pipe sections with EM anomalies out of a possible 10,000 pipe sections. This represents a distress rate of only 0.6 percent – well below industry average. Of the identified anomalies, only seven pipe sections had a relatively high level of distress.

Of the pipes with relatively high distress, two were located within a twinned section and therefore had a lower consequence of failure. The remaining five pipes were located within 3.5 kilometers (2 miles) of each other and are in the same vicinity of failures that occurred in 2010 and 2012.

LHPWSS has since verified and replaced the three most distressed pipes from the five that didn’t have redundancy to mitigate the risk of another failure. Plans to replace the remaining two pipes are scheduled for 2014.

By identifying isolated problems on its major transmission main, LHPWSS is able to avoid completing expensive and challenging replacement projects while maintaining safe pipeline operation. This approach allows capital to be deferred to other projects and prevents the replacement of pipe sections with remaining useful life.

 

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Case Study

Case Study: Lake Huron Primary Water Supply System

In October 2013, LHPWSS and Pure Technologies used advanced non-destructive free-flowing technologies to inspect a critical transmission main for leaks, gas pockets and structural deterioration while the pipeline remained in service. The results were successfully validated in spring 2013.

Assess & Address Pipeline Management Program

Assess & Address Pipeline Management Program

Pure Technologies is helping utilities manage their buried infrastructure through its Assess & Address which can often be implemented for only a fraction of the capital replacement cost.

Following a significant pipe rupture in December 2012, Tulsa Metropolitan Utility Authority (TMUA) performed a detailed structural assessment on a critical section of one of the city’s major drinking water pipelines in November 2013. This recent work builds upon the TMUA’s rapid response forensics investigation completed in January 2013.

To determine the baseline condition of this major transmission main – which is made of 48-inch (1200-mm) Prestressed Concrete Cylinder Pipe (PCCP) – the city dewatered the pipeline and performed a comprehensive internal inspection using visual and sounding techniques, and electromagnetic (EM) technology.

This specific pipeline was constructed in 1975 and had not experienced a failure before December 2012. The 2012 failure caused major commuter disruptions, evacuations and damage to a local church; in an article published in Tulsa World, City Engineering Director Paul Zachary said that this failure cost roughly $400,000 to rectify. The 2013 inspection will help prevent another failure on this transmission main by identifying pipe sections that have distress and could fail if left in operation.

In total, roughly two miles made up of 688 pipe sections were assessed in November using visual and sounding techniques and EM technology.

Visual and sounding inspections are a reliable method of detecting pipes in an advanced state of distress. The inspections require manned entry to the pipeline and dewatering; any pipes judged to be in a state of incipient failure will be reported to allow for immediate replacement or rehabilitation.

Broken pipe

The failed 48-inch pipe section from December 2012.

Staff inside a pipe working with tool

Pure Technologies staff complete verification work on Tulsa’s PCCP water mains.

EM inspections of PCCP pipelines identify the quantity and location of broken wire wraps. The wire wraps in PCCP are the main structural component – as wraps begin to deteriorate and break, the pipe section becomes weaker and more likely to fail catastrophically.

The inspections showed that 81 of 688 pipe sections had broken wire wraps, indicating some level of distress. Based on a structural analysis, it was recommended that 32 of the distressed pipe sections be replaced immediately. In addition, the pipeline has 120 deteriorating joints that should be repaired in the near term. As a result, the City is moving forward with a rapid response construction project to address the pipeline’s deficiencies in early 2014.

Through the use of comprehensive condition assessment, TMUA has increased service reliability and taken major steps toward ensuring another failure does not occur.

By identifying specific areas of distress along this critical transmission main, TMUA has also avoided completing an expensive and time-consuming replacement project of the entire transmission main. This approach helps to preserve capital budget for other projects by avoiding unnecessary replacement of pipe sections in good condition.

The City of Tulsa supplies drinking water to more than 133,500 metered accounts in the City and more than 500,000 people in the metropolitan area. Tulsa’s two water treatment plants treat between 90 and 190 million gallons of drinking water a day. The TMUA is a public trust organization created by City charter. TMUA’s primary responsibilities are to manage, construct, and maintain Tulsa’s water works and sanitary sewer systems, and to fix rates for water and sewer services rendered within its boundaries.

 

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Pipeline Visual & Sounding Inspection Services

Visual Inspections and Soundings have successfully been used to quickly identify pipes in the state of incipient failure. Issues other than wire breaks can also be identified through visual inspections, such as unusual cracking and poorly detailed or damaged joints.

Electromagnetic Pipeline Inspection

Electromagnetic testing provides the best condition assessment data for large diameter PCCP (AWWA C301) and BWP (AWWA C303) pressure pipelines.