Calculate hydraulic pumps and shaft horsepower.
Hydraulic Pump Power
The ideal hydraulic power to drive a bomba it depends
- the mass flow
- liquid density
- at differential height
– is either the static elevation from one height to another or the total head loss component of the system – and can be calculated as
P h(kW) = q ρ gh / (3,6 10 6 )
= qp / (3,6 10 6 ) (1)
Where
P h(kW) = hydraulic power (kW)
q = flow (m 3 /h)
ρ = fluid density (kg/m 3 )
g = acceleration of gravity (9.81 m/s 2 )
h = differential load (m)
p = differential pressure (N/m 2 , Pa)
Horse hydraulic power can be calculated as:
P h(hp) = P h(kW) / 0,746 (2)
Where
P h(hp) = hydraulic power (hp)
Or alternatively
P h(hp) = q gpm h ft SG / (3960 or ) (2b)
Where
q gpm = flow (gpm)
h ft = height differential (ft)
SG = Specific Gravity (1 for water)
η = pump efficiency
Example – Water Pumping
1 m 3 /h of water is pumped at a head of 10 m . The theoretical pump power can be calculated as
P h(kW) = ( 1 m 3 /h ) (1000 kg/m 3 ) (9,81 m/s 2 ) (10 m) / (3,6 10 6 )
= 0,027 kW
Shaft Pump Power
Shaft power – the required power transferred from the motor to the pump shaft – depends on the pump efficiency and can be calculated as
P s(kW) = P h(kW) / h (3)
Where
P s(kW) = shaft power (kW)
η = pump efficiency
Source: https://www.engineeringtoolbox.com/pumps-power-d_505.html









