AODD Configurator

AODD Configurator

Pump Power Rating

12 February 2019

To define the pump power rating we must introduce certain necessary parameters.


This value takes into account the friction between the mechanical parts of the pump.

Usually it has values between 0.88 and 0.96, which are rather high. After all the reduction of friction is one of the key targets to safeguard the life and reliability of the pump.


This value represents the efficiency of the electric motor: usually around 0.9.


This is used to quantify the losses of fluid volume due to the play between pump impeller and casing.

The values are usually between 0.9 and 0.96.

Once these values are defined the total efficiency of the pump will be given by the result of the various efficiencies:

ηt = ηm * ηel * ηvol

Now we can calculate the power of the pump.

Theoretically the power is defined as the work that the machine must perform to move a mass of fluid in the unit of time.

L = work (joule)
g = gravitational acceleration (m/s2)
ρ = fluid density (kg/dm3)
t = time (s)
Hm = total system losses (m)
M = mass (kg)
Qm = volumetric flow rate (m3/s)

The resulting power is expressed in watt (or in kilowatt, where 1 kW = 1000 W).

In order to take into account the various losses, the power must be divided by the total efficiency.

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