Water-Hammer Charts for Various Types of Valves

The importance of the valve closure mode on the magnitude of the water-hammer pressure produced by valve closure is demonstrated by means of an example. It is also shown that the use of various approximate equations to compute this pressure can lead to very poor and unsafe estimates of the maximum transient pressure. Because reasonable estimate of this effect is often essential to good pipeline design, a series of charts are presented which can be used to give an accurate determination of the water-hammer pressure generated by a valve closure. These charts give the maximum value of the transient pressure as a function of the valve closure time, the initial conditions and the pipeline geometry. A number of standard valves are considered in this study encompassing a wide variety of closure modes.