Experimental Investigation of Dynamic Characteristics of Swing and Tilted Disc Check Valves

Abstract

The present work describes an experimental investigation of the dynamic characteristics of check valves, which means experimental examination of closing function and ability to generate pressure transients under different flow decelerations in the pipeline. Two designs of check valves are tested: a swing disc and a tilted disc check valve. The valves are mounted on discharge pipe of a centrifugal pump. The fluid transient is generated by stopping the pump motor from actual velocity to completely stop in a prescribed time. Each of the check valves is subjected to tests covering different pressure levels in the upper reservoir, initial flow rates in the pipeline, several decelerations of pump rotation, three settings of torque acting on the valve disc, three values of the moment of friction forces acting on the valve axis and finally free fall of the disc in stagnant water and air. The test stand, the instrumentation and chosen valves as well as scope and conditions for performing the experiments are described. Selected measured results like angular velocities of the discs, pressures in the pipe at different conditions, and volumetric flow rates are presented and discussed. The dynamic behaviors of the tested valves were compared with each other.