Theoretical Power Equation:



P(kw) = power in kilowatt
Q = flow rate per minutes
dP = pressure drop in bar


Actual power with efficiency



P_act = actual power
n = efficiency, Total motor efficiency (combined mechanical and volumetric) – typically 0.85 to 0.95 (e.g., 0.9 for 90%)

Q = theoretical flow rate (L/min)
Vd = pump displacement (cm^3/rev)
rpm = pump speed rpm (rev/min)

Pump displacement, is the volume of fluid delivered per one shaft revolution