Water Hammer Pressure Surge

Estimate the pressure surge from suddenly stopping flow in a pipe with the Joukowsky equation, free online.

Velocity change Δv (m/s)

Wave speed a (m/s)

Masse volumique (kg/m³)

Pipe length (m)

Valve closing time (s)

À propos de cette calculatrice

The Joukowsky equation gives the maximum surge ΔP = ρ · a · Δv, where a is the pressure-wave speed (about 1000–1400 m/s in water pipes). Surge applies when the valve closes faster than the critical time 2L ÷ a; slower closures give much smaller peaks.