# Valve Pressure Differential for Liquid

on . Posted in Fluid Dynamics

## Valve Pressure Differential for Liquid Formulas

$$\large{ \Delta P = SG \left( \frac{Q}{C_v} \right) }$$     (English units)

$$\large{ \Delta P = SG \left( \frac{Q}{K_v} \right) }$$     (Metric units)

Symbol English Metric
$$\large{ \Delta P }$$ = valve pressure differential  $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$
$$\large{ C_v }$$ = valve flow coefficient $$\large{ dimensionless }$$
$$\large{ K_v }$$ = valve flow coefficient $$\large{ dimensionless }$$
$$\large{ Q }$$ = valve flow rate $$\large{\frac{ft^3}{sec}}$$ $$\large{\frac{m^3}{s}}$$
$$\large{ SG }$$ = specific gravity of liquid (water at 60°F = 1.0000) $$\large{ dimensionless }$$