1. What is Pump Displacement?

Pump displacement refers to the volume of fluid that a pump can move per revolution. It is a critical parameter in hydraulic systems that determines the pump's flow output capacity at a given speed.

2. How Does the Calculator Work?

The calculator uses the pump displacement formula:

Where:

• \( Disp_{pump} \) — Pump displacement (cubic inches per revolution)
• \( Q_p \) — Flow rate (gallons per minute)
• \( RPM_p \) — Pump speed (revolutions per minute)
• 231 — Conversion factor (cubic inches per gallon)

Explanation: This formula calculates how much fluid volume a pump moves with each complete rotation, based on its flow output and operating speed.

3. Importance of Pump Displacement Calculation

Details: Accurate pump displacement calculation is essential for proper hydraulic system design, pump selection, performance prediction, and troubleshooting hydraulic system issues.

4. Using the Calculator

Tips: Enter flow rate in gallons per minute and pump speed in revolutions per minute. Both values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is 231 used in the formula?
A: 231 is the conversion factor from gallons to cubic inches (1 gallon = 231 cubic inches).

Q2: What are typical pump displacement values?
A: Pump displacement varies widely by pump type and size, ranging from less than 0.1 to over 10 cubic inches per revolution for industrial applications.

Q3: How does displacement relate to pump efficiency?
A: Displacement is a theoretical value. Actual flow output may be less due to internal leakage and efficiency factors.

Q4: Can this formula be used for all pump types?
A: This formula is primarily for positive displacement pumps (gear, piston, vane pumps) rather than centrifugal pumps.

Q5: How does temperature affect displacement calculations?
A: Temperature affects fluid viscosity and density, which can impact actual flow rates, but displacement remains a fixed pump characteristic.