1. What is the Pump HP Calculation Formula?

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

Purpose: It helps engineers and technicians properly size pumps for various fluid systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Pump horsepower
• \( Q \) — 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 required to move a specific volume of fluid against a given pressure head, accounting for pump efficiency.

3. Importance of Pump HP Calculation

Details: Proper pump sizing ensures efficient operation, prevents under/over sizing, 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's the 3960 constant in the formula?
A: This converts (GPM × ft × lb/gal) to horsepower (1 HP = 3960 (GPM·ft·lb)/gal).

Q2: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 0.7-0.9 (70-90% efficient), with 0.85 being a common default.

Q3: How do I determine total head?
A: Total head includes static head, friction losses, and pressure differences in the system.

Q4: When would I change the density value?
A: For fluids other than water (8.34 lb/gal), like oil (~7.2 lb/gal) or brine (~8.5-9 lb/gal).

Q5: 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.