Estimating Horsepower Loads for Pumps

The power requirements for pumps should always be obtained from manufacturers if possible, but this may not always be feasible when quick field estimates are needed. The following equation can be used to estimate the power required to drive pumps:

Estimate the pump power requirement by dividing horsepower calculated above by the pump efficiency. An efficiency of approximately 70% can be used for centrifugal pumps, and approximately 80% for vane and gear pumps. Efficiency of reciprocating pumps can  vary significantly depending on pressure and stroke length.  Approximate efficiencies are included in the following table:

This approximation for pump power requirements can be used for quick estimations, or when accurate data cannot be obtained from pump manufacturers. For further information, or for assistance with a belt drive selection contact Gates Product Application Engineering at ptpasupport@gates.com or 303-744-5800.