The Effect of Valve Closure Time on Water Hammer

Abstract Water hammer is a phenomenon that can cause failure in many different fluid systems, including residential water systems, municipal water distribution systems, oil and gas applications, power plants, and chemical processing systems. By understanding the magnitude of the pressure increase that may develop as a result of different system operating conditions, an engineer can better assess the risks of failure and/or the causes of a failure that has already occurred. In this study, an experimental setup at the scale of a residential water system is used to measure the pressure rise generated when varying the fluid velocity and duration of valve closure time. Comparisons are made between the measured pressure values and the estimated pressure values from existing classical models on fluid velocity and valve closure time with respect to water hammer. While the underlying trends of the classical theory are observed in the experiments, a discussion of the notable deviations from theory is presented, along with other considerations that are relevant to measurements in a specific physical system. This study also provides a comparison between the measured results and the standards and methods that are commonly relied upon for certification of plumbing fixtures as required by building codes such as the International Plumbing Code or Uniform Plumbing Code.