The power of a water pump usually refers to the input power, that is, the power on the shaft of the transmission pump of the prime mover, so it is also called shaft power, represented by P;

The effective power of the pump, also known as output power, is represented by Pe. It is the effective energy obtained by the liquid conveyed from the pump per unit time in the pump.

Because head refers to the effective energy obtained from the pump per unit of heavy liquid output by the pump, the product of head, mass flow rate, and gravitational acceleration is the effective energy obtained from the liquid output by the pump per unit of time - that is, the effective power of the pump:

Pe= ρ GQH (W)= γ QH (W)

In the equation ρ-- The density of the liquid conveyed by the pump (kg/m3);

γ-- The weight of the liquid conveyed by the pump (N/m3);

Q - pump flow rate (m3/s);

H - pump head (m);

G - Gravitational acceleration (m/s2).

The difference between shaft power P and effective power Pe is the loss of power within the pump, which is measured by the efficiency of the pump. The efficiency of a pump is the ratio of effective power to shaft power, using η Represent.