WET News

28 WET NEWS SEPTEMBER 2014 Plastic pipe inefficiencies cost the industry thousands of pounds daily – why? The challenge: Pinpointing leaks in plastic pipes C ontrolling water loss due to leakage is crucial to main- taining the sustainability of water supply. Mains renewal is one method of reducing leakage; however as water companies renew their distribution network, the per- centage of plastic pipes within the system is steadily rising. Although plastic pipes have fewer leaks than metallic pipes, finding these leaks is significantly more difficult. The noise gener- ated by a leaking plastic pipe is rapidly attenuated taking up to five times longer to accurately locate the leak. As plastic pipes have become more prevalent in the UK, the inci- dence of leakage on these ageing pipes has also increased. However, leak detection on plastic pipes is an issue for many utilities, as the conventional acoustic technologies are ineffec- tive; even when they do work, they are o en inaccurate leading to excavations that are wrong; wasting time and resources for water utilities. Data gathered by Severn Trent Water indicates that inefficiencies in plastic pipes cost the UK water industry £20,000 a day in addi- tional leak detection time. STW had been experiencing a problem in locating an increasing number of leaks on its plastic pipes, and undertook research to see if the fundamental technology could be improved to a point INSIGHT LEAKAGE MANAGEMENT Extensive field-testing trials were carried out, enabling direct input into the final product. As a result changes were made on both the hardware and software sides of the product where it would work on plastic pipe. Existing technologies that did have good results on plastic pipe were based on Hydrophones (water microphones). However, hydrophones are o en not feasible due to the fact that they need to be mounted on fire hydrants or wash outs, which are not always available. Many of the issues surround- ing plastic pipes are related to the original installation and construction methods that are just now beginning to cause a large number of failures. This is seen by the fact that the problem of finding leaks in plastic pipe has recently become a recur- ring theme at leakage and water conferences, not only in the UK, but also around the world. Severn Trent Water decided to drive inno- vation in the science of leak detec- tion by commissioning funda- mental research into leakage in plastic pipes. Collaborative research with Loughborough University led to the develop- ment of a prototype leak noise correlator that has given a step- change improvement in perfor- mance, out-performing all com- mercially available equipment. The company also approached Echologics Engineering, a move that led to the development of a prototype technology – Leak- finderST. n The award-winning LeakfinderST could be the answer to leakage reduction prayers. A solution: LeakfinderST picks up the vibes E chologics launched its next generation leak noise corre- lator, LeakfinderST, earlier this year following extensive trials at Severn Trent Water. The correla- tor introduced a whole new level of speed and accuracy in locating leaks on plastic pipes. The forward thinking behind LeakfinderST comprises: • Sensors that have a low noise floor and high output in the low frequency range typically generated by leaks on plastic pipe • A method has been devel- oped to automatically calcu- late the velocity of the sound waves in plastic pipe, resulting in more accurate location of leaks • Signal processing has been developed to effectively ana- lyse the low frequencies associated with leaks in plastic pipe • Electronics have been devel- oped that have a lower noise floor to allow for the detec- tion of the low amplitude signals generated by leaks in plastic pipe The result of these innovations is a leak noise correlator that, in testing, has correlated plastic pipe leaks as easily as those on metal- lic pipes, a development that impressed the judges in this year's Water Industry Achievement Awards when the LeakfinderST won the Most Innovative New Technology of the Year. O en, commercial develop- ment is done with very little input from the end users but STW brought significant expertise to the partnership in terms of its understanding of a water utility's requirements for the design of leak detection equipment. The result was not only input from the R&D undertaken, but also input on the user interface and design of the equipment to meet the needs of their techni- cians. These inputs were critical, as one of the major problems in finding leaks on plastic pipes is not only the equipment, but the complexity in the field methods used to find the leaks. The result- ing package is not only techno- logically advanced, but is also easy to use. The product has gone through not only a rigorous design specifi- cation and development process, but also extensive field-testing tri- als where the end users were able to have direct input into the final product. As a result changes were made on both the hardware and so ware sides of the product. These included improvements to the graphical user interface (GUI), as well as to the function of the hardware. This process also made it possible to conduct exten- sive field trials on an operating water system with real leaks, and allowed the demonstration of a business case for the new prod- uct. The business benefits include reduced manpower time to locate leaks, fewer dry holes, and an ability to locate leaks that were previously impossible to find. LeakfinderST is expected to provide an opex benefit of about £5M a year for the UK water indus- try due to reduction in leak detec- tion time and resources. The results from the field trials have been outstanding. STW says the field technicians trialling the equipment have been amazed by how easy the equipment is to use and its ability to pick up leaks undetectable by other equipment on the market. n THE CONCEPT • LeakfinderST provides accurate location of leaks on plastic pipes. • Its electronics have a lower noise floor to allow for the detection of the low amplitude signals generated by leaks in plastic pipe • PC-based software platform and streamlined graphical user interface makes it easy to determine leak position • Automatic noise filter and velocity calculator is highly accurate in pinpointing leaks on any materials of pipe or multiple pipe types, avoiding dry holes • Anyone that has ever used Microsoft Windows can easily and confidently learn how to operate LeakFinderST, says Echologics NEED TO KNOW 1 The product has also improved the performance on metallic pipes in terms of accuracy and speed of correlation 2 Inefficiencies in plastic pipes cost the UK water industry £20,000 a day in additional leak detection time 3 Conventional acoustic technologies are ineffective, and can lead to excavations that are wrong; wasting time and resources for water utilities THE VERDICT "With the number of plastic pipes installed in water utilities' asset bases, the potential of this technology is huge" The WIAA2014 judges "The results from the field trials have been outstanding. Field technicians trialling the equipment have been amazed by how easy the equipment is to use" Severn Trent Water The LeakfinderST leak noise correlator has correlated plastic pipe leaks as easily as those on metallic pipes

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