When a water company was looking to refurbish one its reservoirs, concerns were raised that the increase in pressure might create leaks in one of the ageing concrete pipes it serves. The pipe, first laid in the 1970s, had a history of failures and worries about the integrity of rubber sealed joints and potential burst situations prompted the company to contact WRc.
WRc recommended a SmartBall® survey. SmartBall® is a free-flowing acoustic tool that is used to locate even pinhole-sized leaks and gas pockets in pressurised pipelines. It comprises gyroscopes with acoustic and magnetic sensors. While the former provide a general indication of the line of the pipe, such as bends and angles that are perhaps not shown on plans, the latter is able to correlate the position of leaks with joint locations.
With the SmartBall® running at approximately 2/3rd the speed of flow, the 6km pipeline was fully surveyed in just six hours. Three leaks were found: one at a weeping drain/scour valve; one at a closed scour connection that had not sealed properly; and a final leak at a recently completed temporary repair. Apart from the three leaks, which were duly repaired, the WRC SmartBall® survey delivered the necessary confidence that the remainder of the pipe was leak-free and ready to withstand elevated pressures from the refurbished reservoir. Furthermore, no trapped pockets of air were detected during the survey, indicating that the air valves in the pipeline appeared to be working well.