- Qd Calculated Flow Rate in US GPM
- Qr Rated Pump Transfer Capacity
- Pd Differential Pressure Being Pumped Against, in Pounds Per Square Inch.
- HP Horsepower Required To Drive Pump
- Nd Actual Speed of Pump Shaft in RPM
- Nr Rated Speed of Pump Shaft
- Fs Slippage Factor, A Variable Depending on the Viscosity of the Fluid Pumped
Two variables that must always be manually keyed into the boxes of the performance formulae are Actual Drive Speed, Nd, and the Differential Pressure, Pd. All other variables may be either hand-typed into the formula, or for best accuracy follow the directions below.
- Select a pump model in the table provided to populate the calculator with the rated transfer capacity of the pump (Qr). Rated speed (Nr) is a fixed value based on the particular pump model selected. Select 'next' to continue.
- Select a slippage factor (Fs) value from the table provided. In the absence of a data table, please use the provided slippage factor graph to determine the value for your application, then enter the value by typing directly in the Fs input. Select 'next' to continue.
- Manually enter the actual pump shaft speed in RPM. Select 'next' to continue.
- Manually enter the differential pressure aross the pump. Select 'Calculate' to receive the approximate gallons per minute and horsepower requirements for your application.