Scottish Water first in Europe to deploy PipeDiver™ inline inspection technology

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.