What is RPM to Flow Rate?
RPM to Flow Rate converts pump rotational speed into volumetric flow rate. This is fundamental in hydraulic and fluid system design, helping engineers select the right pump, size piping, and optimize system performance.
How to Calculate Flow Rate from RPM
For imperial units (GPM):
[\text{Flow Rate} = \frac{\text{RPM} \times D}{231}]
For metric units (LPM):
[\text{Flow Rate} = \frac{\text{RPM} \times D}{1{,}000}]
Where:
- Flow Rate is in gallons per minute (GPM) or liters per minute (LPM).
- RPM is the pump speed in revolutions per minute.
- D is the pump displacement per revolution (in³ or cm³).
- 231 converts in³ to gallons. 1,000 converts cm³ to liters.
Calculation Example
A pump runs at 500 RPM with a displacement of 3 in³/revolution.
[\text{Flow Rate} = \frac{500 \times 3}{231} = \frac{1{,}500}{231} = 6.494]
The flow rate is approximately 6.494 GPM.
Metric Example
A pump runs at 800 RPM with a displacement of 50 cm³/revolution.
[\text{Flow Rate} = \frac{800 \times 50}{1{,}000} = \frac{40{,}000}{1{,}000} = 40]
The flow rate is 40 LPM.