1. What is a Pool Pump RPM to GPM Calculator?

Definition: This calculator estimates the flow rate in gallons per minute (GPM) based on pump RPM, displacement, and head pressure.

Purpose: It helps pool technicians and engineers determine the actual flow rate of a pump at different operating conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( RPM \) — Pump speed (revolutions per minute)
• \( D_p \) — Pump displacement (cubic inches per revolution)
• \( H \) — Head pressure (feet of head)

Explanation: The formula accounts for pump speed, displacement volume, and the resistance created by head pressure.

3. Importance of Flow Rate Calculation

Details: Proper flow rate estimation ensures adequate pool circulation, proper filtration, and efficient pump operation.

4. Using the Calculator

Tips: Enter the pump RPM, displacement (typically found in pump specifications), and total head pressure. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is pump displacement?
A: The volume of fluid moved per revolution of the pump shaft, typically measured in cubic inches per revolution (in³/rev).

Q2: How do I find the head pressure?
A: Head pressure is the total resistance the pump must overcome, including pipe friction and elevation changes.

Q3: Why is 231 used in the formula?
A: 231 cubic inches equals 1 gallon, used to convert cubic inches per minute to gallons per minute.

Q4: What's a typical flow rate for residential pools?
A: Most residential pools require 40-60 GPM for proper circulation and filtration.

Q5: Does this account for pump efficiency?
A: No, this is a theoretical calculation. Actual flow may be lower due to pump efficiency losses.