TPi July 2018

Products & developments

Asset management begins with leak detection

SmartBall ® (a free-swimming tool) and Sahara ® (with a tethered sensor). Both tools are equipped with an acoustic sensor that can locate very small leaks (as small as 0.1 l/min) with high location accuracy. The SmartBall platform identifies leaks and gas pockets in large-diameter pipelines while the line remains in service, minimising disruption. The free- swimming ball contains leak detection circuitry and is released untethered into the water flow, often through an air valve or hydrant (any 100mm opening). The SmartBall follows the water flow and is tracked by surface-mounted sensors as it rolls through the pipe, making a continuous recording of the acoustic activity in the pipeline. At a downstream location, the ball rolls into the retrieval device and is extracted from the pipe. The data is then evaluated to report the presence of leaks and gas pockets. Since the SmartBall is propelled by the water flow, it can be used to survey the subject main for long distances (with a battery life of up to 20 hours) in one deployment. As a result, modifications to the main

are significantly reduced. The Sahara tethered inspection platform identifies leaks and gas pockets by providing acoustic data on the presence of leaks for distances up to 1,800m (6,000 feet). The tool also has the ability to map pipeline alignment, and is equipped with CCTV. It can be inserted into an active pipeline through almost any tap 2" or greater. As the Sahara tool enters the pipe, the flow velocity of the water inflates a small parachute that pulls the tool through the pipe, with the probe lighting the way, 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 ±0.5m (18"). This enables users to know in real time where leaks are located. Pure Technologies – Canada

It takes more than luck and traditional acoustic correlation methods to locate a suspected leak on large critical mains. Not all leaks are obvious, and some leaks can seep for years without visibly surfacing, putting utilities at risk of catastrophic failure. A proactive leak detection strategy plays an important role in any asset management programme, allowing utilities to obtain the general condition of their mains, since a leak not only represents water loss, but can also indicate the potential for pipeline failure. Inline leak detection technologies use non-destructive methods in which acoustic sensors are inserted into a pressurised pipeline. The ‘hissing’ sound or vibration resulting from a leak in a pipe transmits an acoustic signal collected by the sensor when passing the leak site. The amplitude and frequency of the sound depends on the pipe material and internal pressure, and is easy to distinguish from other pipeline sounds. Pure Technologies has developed two inline leak detection platforms for large- diameter pipelines of all materials:

No risk of lost welds with weld purge film Low-cost weld purging can prove complex, with many welders making savings by constructing their own foam or paper dams in order to reduce the purge volume and make weld purging times shorter. However, such improvised purge dams have technical limitations that can lead to loss of welds when they leak or slip from position, flooding the welding zone with oxygen. their dams do not come loose during welding, thus, no more lost welds.” Weld Purge Film kits can be used on pipe diameters up to 900mm (36") and for temperatures up to 300°C (572°F) without the material burning, coming loose and losing the weld purge.

The kits minimise gas usage and reduce purge time; eliminate the need to clean; and prevent failed welds. Another technical advantage of using water- soluble film instead of other materials is the transparency of the film dams, allowing the welder to see the weld root as it is being laid. Vapour pressure of the film is low and does not outgas harmful elements during welding that can mix with the hot metal and cause metallurgical defects. The Argweld film does not contain water, unlike paper and sponge products. Huntingdon Fusion Techniques – UK

The water-soluble Weld Purge Film allows dams to be cut easily with the safety knife supplied. Once they are fixed into position using the water- soluble Weld Purge Super Adhesive ® , also provided, they produce an impenetrable purge barrier that can easily be washed away during hydrostatic testing of the pipe or by normal wash-out.

To overcome these challenges, Huntingdon Fusion Techniques (HFT) has designed and developed the Argweld ® Weld Purge Film ® kits. Ron Sewell, chairman for HFT, said, “With the use of our low-cost Weld Purge Film, welders can ensure that



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