A Study on Water Hammer by Check Valve in Water Supply Piping System : Part 1-Experimental Method and Results of Water Hammer by the Comparison of Several Check Valves

Abstract

Water hammer is attracting the attention of engineers for its importance in the appropriate design of water supply piping system. This report attempts to present the experimental method and study on it by using check valves. The study consists of experiment, survey, and numerical procedure. The results of the study on the water hammer by using several check valves through experimental comparison are described as follows, 1) The maximum pressure rising rate increases as the weight of the check valve decreases. 2) The maximum pressure rising rate increases as the time from the point of electricity shut-off to that of the onset of pressure rising (Pt.C) is getting long or the time from Pt.C to the point of the first peak after Pt.C is getting short. 3) The column separetion occures when the pipe length from the reflection point of pressure wave to the check valve is short. 4) The water level of the pressure tank is to be kept higher to avoid surging during experiments. The survey and numerical studies on water hammer by using check valves are to be described in Part 2.