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Case Study

Industrial Steel Mill North America

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.