1. What is Pump Horsepower Calculation?

Pump horsepower calculation determines the power required to move fluid through a system at a specified flow rate against a given head, accounting for fluid properties and pump efficiency.

2. How Does the Calculator Work?

The calculator uses the pump horsepower formula:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM)
• \( H \) — Total dynamic head (feet, ft)
• \( SG \) — Specific gravity of fluid (dimensionless, 1 for water)
• \( \eta \) — Pump efficiency (decimal, 0-1)
• 3960 — Conversion factor (ft-lb/min per HP)

Explanation: The formula calculates the power needed to move a fluid against gravity and friction losses, adjusted for the fluid's density and the pump's efficiency.

3. Importance of Pump Horsepower Calculation

Details: Accurate horsepower calculation ensures proper pump selection, prevents motor overload, optimizes energy consumption, and maintains system efficiency.

4. Using the Calculator

Tips: Enter flow rate in GPM, head in feet, specific gravity (1 for water), and pump efficiency as a decimal (e.g., 0.85 for 85%). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is typical pump efficiency?
A: Centrifugal pumps typically range from 50-85% efficiency, with larger pumps generally being more efficient.

Q2: How does specific gravity affect horsepower?
A: Higher specific gravity fluids (denser than water) require more horsepower to pump at the same flow rate and head.

Q3: What is total dynamic head?
A: It's the total equivalent height the pump must overcome, including static lift, friction losses, and pressure differences.

Q4: 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.

Q5: What about viscous fluids?
A: This formula works best for water-like fluids. For viscous fluids, specialized calculations are needed.