Key words: Water Hammer, Leak detection, Elastic pipe, viscoelastic pipe, Transient pressure.

Abstract: This paper further investigates leaks detection in elastic and viscoelastic pipes based on the analysis of water hammer wave. Leak as an internal exciter and a discontinuity that occurs in a hydraulic system may affect the waveform. Its effects on the pressure wave at the end section of a reservoir-pipe-valve system can be used as a tool for its location and sizing. The leak modeled as an orifice is located in the studied system either with elastic or viscoelastic behavior. Its location is given by analyzing the head pressure at the valve either in the time or the frequency domain. The effect of the pipe-wall elasticity (instantaneous elastic response) and viscoelasticity (retarded –viscoelastic response) on the leak detection are investigated either in time or frequency domain. Finally a comparison between the two analyses for leak detection is drawn.