Excess pressure due to water hammer


Water hammer (or, more generally, fluid hammer) is a pressure surge or wave caused when a fluid (usually a liquid but sometimes also a gas) in motion is forced to stop or change direction suddenly (momentum change). A water hammer commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. It is also called hydraulic shock. When a valve with a volumetric flow rate is closed, an excess pressure is created upstream of the valve

Related formulas


ΔPExcess pressure (overpressure) (Pa)
ZhHydraulic impedance (kg/s*m4)
QVolumetric flow rate (m3/s)