Pump Gpm Calculator

Pump GPM Formula:

\[ GPM = \frac{RPM \times Displacement}{231} \]

GPM:

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1. What is the Pump GPM Formula?

The Pump GPM (Gallons Per Minute) formula calculates the flow rate of a pump based on its rotational speed (RPM) and displacement volume. It's a fundamental equation in hydraulic system design and analysis.

2. How Does the Calculator Work?

The calculator uses the GPM formula:

\[ GPM = \frac{RPM \times Displacement}{231} \]

Where:

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

Explanation: The formula converts the volumetric displacement of the pump into a flow rate, accounting for the conversion between cubic inches and gallons.

3. Importance of GPM Calculation

Details: Accurate GPM calculation is essential for proper hydraulic system design, pump selection, and ensuring systems meet performance requirements for various applications.

4. Using the Calculator

Tips: Enter RPM in revolutions per minute and displacement in cubic inches per revolution. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

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

Q2: What is typical displacement for hydraulic pumps?
A: Displacement varies widely by pump type and size, typically ranging from 0.1 in³/rev for small pumps to over 10 in³/rev for larger industrial pumps.

Q3: Does this formula account for pump efficiency?
A: No, this formula calculates theoretical flow. Actual flow will be less due to volumetric efficiency losses from internal leakage and other factors.

Q4: Can this formula be used for all pump types?
A: This formula is specifically for positive displacement pumps (gear, piston, vane pumps). It doesn't apply to centrifugal or other dynamic pumps.

Q5: How does temperature affect the calculation?
A: Temperature affects fluid viscosity which can impact pump efficiency, but the basic formula remains the same for theoretical flow calculation.