Water Pump HP Calculators
Water Pump HP Calculator
I once bought the wrong pump because I didn’t know how to calculate the capacity, that is why we made this water pump HP calculation formula calculator for fellow engineers.
What is a water pump
A water pump is a machine or device used for moving water from one place to another, usually by increasing the thrust of the water.
In simple word, pumps work by converting mechanical energy (from an electric motor or machine) into kinetic energy (water velocity) and potential energy (pressure or head of water).
The working ways and fuctions are divided into 2 types
- Lifting water (Suction): the pump creates a low-pressure chamber (partial vacuum) on the suction side so that atmospheric pressure pushes water into the pump.
- Pushing water (Discharge): after the water enters, the pump (through the impeller or piston) provides thrust for the water to move at a speed and pressure sufficient to reach a certain height or distance.
Curve table as a complement to the water pump HP calculation formula
Water Pump Performance Curve (SI Units)
Water pump HP calculation formula
HP = GPM x Head x SG ÷ 3960 x Eff
Case examples
This is one real case examples of how to use the water pump HP calculation formula
A project needs a pump to deliver water with a discharge (Flow) of 100 GPM (Gallon per Minute) to a total height (Head) of 15 meters (total head after adding pipe friction loss is estimated at 50 feet). It is assumed that the pump efficiency (Eff) used is 60% (0.6). How much is the minimum pump motor (HP) required? SG (Specific Gravity) = 1 because we talked about water. Use the water pump HP calculation formula to calculate:
HP = GPM x Head x SG ÷ 3960 x Eff
HP = 100 x 50 x 1 ÷ 3960 x 0,6
HP = 5000 ÷ 2376
HP = 2,10 HP.
We recommended the project to buy a minimum 3 HP pump or equivalent to 2 kW. You can check whether this answer is same as the calculator’s answer.
The cost of the pump is definitely related to the tank or tube. If want to calculate the volume of the tube using a calculator, please use it for free at this link .