1. What is the Pump Power Required Formula?

Definition: This calculator determines the horsepower required by a pump to move fluid at a specified flow rate against a given head.

Purpose: It helps engineers, technicians, and system designers properly size pumps for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower required
• \( Q \) — Flow rate (gallons per minute, GPM)
• \( H \) — Total head (feet, ft)
• \( \rho \) — Fluid density (pounds per gallon, lb/gal)
• \( \eta \) — Pump efficiency (decimal between 0 and 1)

Explanation: The formula calculates the power needed to move a specific volume of fluid against gravity and system resistance.

3. Importance of Pump Power Calculation

Details: Accurate power calculation ensures proper pump selection, energy efficiency, and system reliability while preventing undersizing or oversizing.

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 (H)?
A: Total head is the height the liquid needs to be pumped plus friction losses in the system, measured in feet.

Q2: Why is 3960 in the formula?
A: This constant converts (GPM × ft × lb/gal) to horsepower (1 HP = 3960 (GPM·ft·lb)/gal).

Q3: What's a typical pump efficiency?
A: Most centrifugal pumps have 60-85% efficiency (0.6-0.85), while positive displacement pumps can reach 90%.

Q4: How do I account for viscous fluids?
A: Use the actual fluid density and consider that efficiency may decrease with higher viscosity.

Q5: Should I add a safety factor?
A: Yes, it's common to add 10-20% to the calculated HP to account for system variations and future needs.