1. What is the Hydraulic Pump GPM Equation?

The hydraulic pump GPM (gallons per minute) equation calculates the flow rate of a hydraulic pump based on its displacement and rotational speed. It's fundamental for hydraulic system design and analysis.

2. How Does the Calculator Work?

The calculator uses the hydraulic pump flow rate equation:

Where:

• \( GPM \) — Flow rate in gallons per minute
• \( Displacement \) — Pump displacement in cubic inches per revolution
• \( RPM \) — Pump speed in revolutions per minute
• \( 231 \) — Conversion factor (cubic inches per gallon)

Explanation: The equation converts the volumetric displacement per revolution into flow rate based on how fast the pump is turning.

3. Importance of GPM Calculation

Details: Knowing the flow rate is essential for proper hydraulic system design, ensuring adequate fluid delivery to actuators, and preventing pump cavitation or excessive pressure drops.

4. Using the Calculator

Tips: Enter pump displacement in in³/rev and RPM. Both values must be positive numbers. The calculator will compute the flow rate in gallons per minute.

5. Frequently Asked Questions (FAQ)

Q1: Why is 231 the conversion factor?
A: There are 231 cubic inches in a US gallon, which converts the displacement volume to gallons.

Q2: Does this work for all pump types?
A: This applies to positive displacement pumps (gear, piston, vane). It doesn't account for efficiency losses or slip.

Q3: How does efficiency affect actual flow?
A: Actual flow may be less due to volumetric efficiency. Multiply theoretical GPM by pump efficiency (typically 85-95%) for real-world values.

Q4: What's a typical displacement for hydraulic pumps?
A: Common ranges are 0.1-10 in³/rev for small pumps, up to 20+ in³/rev for large industrial pumps.

Q5: How does GPM relate to system pressure?
A: Flow rate (GPM) determines actuator speed, while pressure determines force. They're related through power (HP = GPM × PSI / 1714).