Tracking down the source of a leak in water pipes can be a tricky business. Current techniques rely on acoustic sensing with microphones often used to identify noise resulting from pressurized water escaping the pipe. In plastic pipes in particular, that noise can fall away quickly, making leak detection difficult and time consuming. Researchers at the University of Sheffield claim to have developed a much more accurate system that locates leaks by sending a pressure wave along the pipe that sends back a signal if it passes any anomalies in the pipe’s surface.

The system, which can be fitted to a standard water hydrant, consists of a valve that is opened and closed rapidly to generate a pressure wave that is sent down the pipe. When this wave encounters any unexpected features, such as a leak or crack in the pipe’s surface, it sends back a reflection that can be analyzed to reveal the location and size of the leak. The system can be calibrated onsite, factoring in the size of the pipe and the speed of the pressure wave, to reliably and rapidly locate leaks.

The device was originally developed by a team at Sheffield University’s Department of Mechanical Engineering led by Professor Stephen Beck, which partnered with colleagues in the University’s Department of Civil and Structural Engineering, and Yorkshire Water to develop it into a prototype device.

In trials carried out at Yourkshire Water’s field operators training site in Bradford, the prototype device was able to locate leaks in cast iron pipes with an accuracy to within one meter (3.3 ft), while leaks in plastic pipes were located to within 20 cm (7.8 in).

"We are very excited by the results we’ve achieved so far,” said Dr James Shucksmith, in the Department of Civil and Structural Engineering at the University of Sheffield, who led the trial, the results of which appear in the Journal – American Water Works Association. “We are able to identify the location of leaks much more accurately and rapidly than existing systems are able to, meaning water companies will be able to save both time and money in carrying out repairs.

According to U.K.’s Water Services Regulation Authority (Ofwat), between 20 and 40 percent of the total water supply of England and Wales can be lost through damaged pipes. And it’s a pretty safe assumption that water suppliers pass on the cost of that wasted water, as well as the costs incurred tracking down and repairing leaks, to the consumer somewhere along the line. Hopefully the time and money savings provided by the system invented at Sheffield University are also passed on to the consumer if and when the device gets widespread adoption.

The development team is now looking for an industrial partner with the goal of manufacturing the system commercially.

Source: University of Sheffield