1. What is Water Pump Capacity Calculation?

Definition: This calculator estimates the water pump capacity in gallons per minute (GPM) based on horsepower, head, and pump efficiency.

Purpose: It helps engineers, plumbers, and irrigation specialists determine the flow rate of water pumps for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Pump capacity (gallons per minute)
• \( HP \) — Horsepower of the pump
• \( H \) — Total dynamic head (feet)
• \( \eta \) — Pump efficiency factor (0-1)

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

3. Importance of Pump Capacity Calculation

Details: Proper pump sizing ensures efficient water delivery, prevents pump overload, and matches system requirements for irrigation, plumbing, or industrial applications.

4. Using the Calculator

Tips: Enter the pump horsepower, total head in feet, and efficiency factor (default 0.85). All values must be > 0, with efficiency between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is total dynamic head?
A: It's the total equivalent height the pump must overcome, including vertical lift, pipe friction, and pressure differences.

Q2: What's a typical efficiency factor?
A: Most pumps operate at 50-85% efficiency (0.5-0.85), with centrifugal pumps typically around 0.7-0.85.

Q3: Why is 3960 in the formula?
A: This constant converts horsepower (550 ft-lb/sec) to foot-pounds per minute (33,000 ft-lb/min) divided by water weight (8.34 lb/gallon).

Q4: How does head affect capacity?
A: Higher head reduces capacity - pumps move less water against greater resistance or height.

Q5: Can I use this for other liquids?
A: The formula works for water. For other liquids, replace 8.34 with the liquid's weight per gallon.