1. What is Pump Horsepower Calculation?

The pump horsepower calculation determines the motor power required to move fluid through a piping system. It accounts for flow rate, pressure head, fluid properties, and pump efficiency.

2. How Does the Calculator Work?

The calculator uses the standard horsepower formula:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total dynamic head in feet (ft)
• \( SG \) — Specific gravity of fluid (1.0 for water)
• \( \eta \) — Pump efficiency as decimal (0.0-1.0)
• 3960 — Conversion factor (ft-lb/min per HP)

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

3. Importance of Proper HP Calculation

Details: Correct horsepower calculation ensures proper pump selection, prevents motor overload, optimizes energy use, and extends equipment life.

4. Using the Calculator

Tips: Enter flow rate in GPM, total head in feet, specific gravity (1.0 for water), and pump efficiency (typically 0.7-0.9 for centrifugal pumps). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is total dynamic head?
A: The total resistance the pump must overcome, including static head, friction loss, and pressure differences.

Q2: How do I determine pump efficiency?
A: Manufacturer curves typically provide efficiency at various operating points. 0.85 is a common default for estimation.

Q3: Should I add a safety factor?
A: Yes, typically add 10-20% to calculated HP to account for system variations and future needs.

Q4: What's the difference between BHP and WHP?
A: Brake HP (BHP) is power at pump shaft, Water HP (WHP) is hydraulic power delivered to fluid. This calculator gives BHP.

Q5: How does viscosity affect HP?
A: Higher viscosity fluids require more power. For viscous fluids, use correction factors or specialized calculators.