A methodology for predicting check valve slam

Check valve slam, a problem commonly associated with check valves, is often discovered during startup of the pump system, by which time it is too late to easily overcome. An extensive program of valve flow testing conducted to develop profiles of slamming characteristics for various types of check valves is described. Research results led to a methodology designed to help system designers predict and ultimately prevent check valve slam through selection of valves that are less prone to slam and associated water hammer. Different check valves offer different advantages such as reduced cost, low head loss, or special flow characteristics. Ultimately, the best check valve is the one that meets the requirements of a particular installation or application. Consulting engineers and utilities alike can use the data that are provided in this article, combined with field experience and other readily available information, to make informed choices and resolve check valve problems.