Pressure waves as a tool for leak detection in closed conduits

In recent decades, growing water demand and a scarcity of easily exploitable high-quality water sources has reinvigorated interest in the further development of already stressed groundwater resources. Since leakage reduction often means the acquisition of new high-quality water resources, utility managers are realizing that water loss must be considered in plans to extend water supply and leak detection is now perceived as a money-saving expense. Among leak detection methodologies, those based on transient analysis can be some of the fastest and cheapest. This article briefly outlines the properties of pressure waves in closed single pipe systems. Past findings from the analysis of pressure signals within the time domain framework are reviewed and time series of pressure variations acquired in laboratory experiments at one measurement section are examined. Emphasis is placed on the analysis of transient test results in the frequency domain and the use of the wavelet transform for interpreting pressure signals. Both a single pipe system and a wastewater outfall system are examined and discussed.