Water Hammer Pressure Surge
Estimate the pressure surge from suddenly stopping flow in a pipe with the Joukowsky equation, free online.
About this calculator
The Joukowsky equation gives the maximum surge ฮP = ฯ ยท a ยท ฮv, where a is the pressure-wave speed (about 1000โ1400 m/s in water pipes). Surge applies when the valve closes faster than the critical time 2L รท a; slower closures give much smaller peaks.