n = speed of pump impeller (rpm)
= volumetric flow rate of pump (gpm or ft3/hr)
Hp = head developed by pump (psid or feet)
p = pump power (kW)
Using these proportionalities, it is possible to develop equations relating the condition at one
speed to those at a different speed.
A cooling water pump is operating at a speed of 1800 rpm. Its flow rate is 400 gpm at
a head of 48 ft. The power of the pump is 45 kW. Determine the pump flow rate, head,
and power requirements if the pump speed is increased to 3600 rpm.