1. What is Hydraulic Pump Flow Rate?

Definition: This calculator estimates the flow rate of a hydraulic pump in gallons per minute (GPM) based on pump speed and displacement.

Purpose: It helps hydraulic system designers and maintenance technicians determine pump performance and system requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( RPM \) — Pump rotational speed (revolutions per minute)
• \( D_p \) — Pump displacement (cubic inches per revolution)
• \( 231 \) — Conversion factor (cubic inches per gallon)

Explanation: The pump's displacement per revolution multiplied by its speed gives the total displacement per minute, which is then converted to gallons.

3. Importance of Pump Flow Rate Calculation

Details: Accurate flow rate calculation ensures proper system performance, prevents pump overload, and helps select appropriate components.

4. Using the Calculator

Tips: Enter the pump RPM and displacement (in³/rev). Both values must be > 0. The result shows the theoretical flow rate in GPM.

5. Frequently Asked Questions (FAQ)

Q1: Why 231 in the formula?
A: 231 cubic inches equals 1 US gallon, converting the displacement volume to gallons.

Q2: Is this the actual or theoretical flow rate?
A: This calculates theoretical flow. Actual flow may be less due to efficiency losses (typically 85-95% of theoretical).

Q3: How do I find my pump's displacement?
A: Check manufacturer specs or calculate from bore diameter, stroke, and number of pistons/gears/vanes.

Q4: What's a typical RPM range for hydraulic pumps?
A: Most pumps operate between 1200-1800 RPM, but some high-speed pumps go up to 3000+ RPM.

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