A NOVEL SENSOR FOR DETECTING LEAKS IN BURIED PLASTIC WATER PIPES

摘要

Water leaks are a topic of great concern in Britain and many other countries, because of decreasing water supplies and the deterioration of old pipework. Acoustic techniques are widely used to locate leaks in buried water pipes. However, difficulties are often encountered when attempting to detect a leak in a plastic pipe, as the leak noise signals attenuate very rapidly away from the leak, and so may be extremely small; identifying suitable sensors which can be easily deployed and are sufficiently sensitive has been problematic. PVDF ring sensors have been proposed and demonstrated successfully in laboratory conditions. Unfortunately, in many parts of the water distribution system, not all of the circumference of the pipe is accessible, so the sensor cannot be effectively positioned around the pipe. In this paper, it is proposed that the ring sensor is used in a modified configuration: a flexible pipe instrumented with the ring sensor is connected to the pipe, via a fire hydrant or other standard access point. Some theoretical modelling, based on extensive previous work, has been carried out to determine the sensitivity of this type of sensor to pressure fluctuations in the main pipe. Experimental work has also been undertaken to support the theoretical findings.