Parameter to minimize false alarms in Negative Pressure Wave leak detection systems

The presence of leaks in pipeline systems that transport fuel or drinking water causes economic losses and environmental impact. To minimize these effects, the leak must be detected in real time. In this sense, the Negative Pressure Wave (NPW) method shows high efficiency. However, it has been reported that it emits false leak alarms, since NPWs originating outside the monitored section are detected as leaks. Therefore, in this work, the behavior of NPWs originating inside and outside a pipeline section monitored by two pressure sensors was evaluated, to find a parameter that allows them to be differentiated. To do this, NPWs were generated, with known origin points with respect to the location of the sensors. When generating the NPWs, it was observed that the Delay Time (DT) to be detected by both sensors is maximum when the NPWs are generated outside the monitored section and minimum when the NPWs are generated at 50 % of the length between the sensors. Therefore, it is concluded that by quantifying the Tr parameter of the NPWs in the sensors, leaks generated outside the monitored section can be discriminated, reducing false alarms.