Portable pressure wave-maker for leak detection and pipe system characterization

This article illustrates the performance of the portable pressure wave maker (PPWM; patent pending) device for leak detection and pipe characterization used in the water engineering laboratory of the University of Perugia, Italy. The device consists of a steel vessel filled with pressurized air and water that is connected to a test pipe by a short conduit with a connection valve at its end. By a pressure value being fixed in the PPWM that is higher than the pressure in the pipe, a pressure wave propagates in the line when the connection valve is opened. Singularities (e.g., junctions, partial blockages, and leaks) will give rise to the formation of reflected waves whose arrival time and amplitude—recorded in one or more sections of the pipe—allow their detection. Because of its modest dimensions, the PPWM can easily be carried to plants and facilities as part of a transient test-based leak-detection and system-characterization campaign. First, experimental evidence of PPWM device behavior for pipe characterization is shown. Then optimal operational conditions are determined by means of a numerical model and are tested in the laboratory. Finally, a simple formula for evaluating the generated pressure wave is given.