1. What is Pump Motor Capacity Calculation?

Definition: This calculator determines the required horsepower for a pump motor based on flow rate, total head, fluid density, and pump efficiency.

Purpose: It helps engineers and technicians properly size pump motors for various fluid transfer applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower required (HP)
• \( Q \) — Flow rate (gallons per minute)
• \( H \) — Total head (feet)
• \( \rho \) — Fluid density (pounds per gallon)
• \( \eta \) — Pump efficiency (decimal, 0-1)

Explanation: The formula calculates the power needed to move a specific volume of fluid against a given head pressure, adjusted for pump efficiency.

3. Importance of Pump Motor Sizing

Details: Proper pump motor sizing ensures efficient operation, prevents motor overload, and reduces energy costs.

4. Using the Calculator

Tips: Enter the flow rate (GPM), total head (ft), fluid density (default 8.34 lb/gal for water), and pump efficiency (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is total head in pump calculations?
A: Total head is the sum of static head, friction head, and pressure head that the pump must overcome.

Q2: Why is pump efficiency important?
A: Efficiency accounts for energy losses in the pump system. Typical values range from 0.7 to 0.9 (70-90%).

Q3: What density should I use for other fluids?
A: For other fluids, use their specific weight (e.g., 6.6 lb/gal for gasoline, 9.5 lb/gal for seawater).

Q4: Should I add a safety factor?
A: Yes, it's common to add 10-20% to the calculated HP for safety margins and future needs.

Q5: What's the 3960 constant in the formula?
A: This is a conversion factor that combines unit conversions for GPM, feet, lb/gal to HP.