Leak detection in pipes by frequency response method

The frequency response method is used to determine the location and rate of leakage in open loop piping systems. A steady-oscillatory flow, produced b y the periodic opening and closing of a valve, is analyzed in the frequency domain by using the transfer matrix method, and a frequency response diagr am at the valve is developed. For a system with leaks, this diagram has add itional resonant pressure amplitude peaks (herein referred to as the second ary pressure amplitude peaks) that are lower than the resonant pressure amp litude peaks (herein called primary amplitude peaks) for the system with no leaks. Several piping systems are successfully analyzed for all practical values of the friction factor to detect and locate individual leaks of up t o 0.5% of the mean discharge. The method, requiring the measurement of pres sure and discharge fluctuations at only one location, has the potential to detect leaks in real-life pipe systems conveying different types of fluids, such as water, petroleum, and so on.