1. What is a Well Pump Flow Rate Calculator?

Definition: This calculator estimates the flow rate of a well pump in gallons per minute (GPM) based on pump horsepower, efficiency, and total head.

Purpose: It helps determine how much water a pump can deliver, which is crucial for well system design and troubleshooting.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( HP \) — Pump horsepower
• \( \eta \) — Pump efficiency (0-1)
• \( H \) — Total head (feet)

Explanation: The formula converts mechanical power to hydraulic power, accounting for pump efficiency and the work needed to lift water.

3. Importance of Flow Rate Calculation

Details: Proper flow rate estimation ensures the pump meets water demand, operates efficiently, and doesn't overload the system.

4. Using the Calculator

Tips: Enter the pump horsepower, efficiency (default 0.85 for 85%), and total head in feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is total head?
A: Total head is the vertical distance from the water level to the discharge point plus friction losses in the piping system.

Q2: What's a typical pump efficiency?
A: Most submersible pumps operate at 70-85% efficiency (0.7-0.85). Check manufacturer specs for exact values.

Q3: Why is 3960 in the formula?
A: This is a conversion factor that relates horsepower to foot-pounds per minute (1 HP = 3960 ft-lb/min).

Q4: How do I find my pump's horsepower?
A: Check the pump nameplate or manufacturer specifications. Common residential pumps are 1/2 HP to 1 HP.

Q5: Does this account for pipe friction losses?
A: No, the total head input should include both static head and friction losses for accurate results.