# Water Hammer Maximum Surge Pressure Head

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

## Water Hammer Maximum Surge Pressure Head Formula

$$\large{ h_{sph} = \frac { \alpha \; \Delta v } { g } }$$     (maximum surge pressure head)

$$\large{ p_{spf} = \frac { \alpha \; \Delta v \; \gamma_f } { 144\; g } }$$     (maximum surge pressure for a fluid)

$$\large{ p_{spw} = \frac { \alpha\; \Delta v } { 2.31\;g } }$$     (maximum surge pressure for a water)

Symbol English Metric
$$\large{ p_{spf} }$$ = maximum surge pressure for fluid $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$
$$\large{ p_{spw} }$$ = maximum surge pressure for water $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$
$$\large{ h_{sph} }$$ = maximum surge pressure head $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$
$$\large{ \Delta v }$$ = fluid velocity change $$\large{\frac{ft}{sec}}$$ $$\large{\frac{m}{s}}$$
$$\large{ g }$$ = gravitational acceleration $$\large{\frac{ft}{sec^2}}$$ $$\large{\frac{m}{s^2}}$$
$$\large{ \alpha }$$  (Greek symbol alpha) = pressure wave velocity $$\large{\frac{ft}{sec}}$$ $$\large{\frac{m}{s}}$$
$$\large{ \gamma_f }$$  (Greek symbol gamma) = unit weight of fluid $$\large{\frac{lbm}{ft^3}}$$ $$\large{\frac{N}{m^3}}$$ 