Pump RPM to Flow Rate Calculator

Flow Rate Formula:

\[ Q = \frac{RPM \times D_p}{231} \]

Flow Rate (GPM):

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1. What is a Pump RPM to Flow Rate Calculator?

Definition: This calculator determines the flow rate in gallons per minute (GPM) based on pump RPM and displacement volume.

Purpose: It helps hydraulic engineers, mechanics, and technicians estimate pump performance and system requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q = \frac{RPM \times D_p}{231} \]

Where:

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

Explanation: The formula multiplies RPM by displacement to get total volume pumped per minute, then converts cubic inches to gallons.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation is crucial for system design, performance evaluation, and troubleshooting hydraulic systems.

4. Using the Calculator

Tips: Enter the pump RPM and displacement per revolution (in cubic inches). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is 231 the conversion factor?
A: There are 231 cubic inches in one US gallon, which converts the volume units.

Q2: What's a typical displacement for hydraulic pumps?
A: Common values range from 0.1 in³/rev for small pumps to 10+ in³/rev for large industrial pumps.

Q3: Does this account for pump efficiency?
A: No, this calculates theoretical flow. Actual flow would be less due to volumetric efficiency.

Q4: How do I find my pump's displacement?
A: Check manufacturer specifications or calculate from pump geometry (for gear pumps: tooth volume × number of teeth).

Q5: Can I use this for any pump type?
A: This works for positive displacement pumps (gear, piston, vane). Not for centrifugal pumps which have variable displacement.