1. What is Pump Horsepower?

Pump horsepower (HP) is the power required to move a fluid at a specified flow rate against a specific head (pressure). It accounts for the fluid's properties and the pump's efficiency.

2. How Does the Calculator Work?

The calculator uses the pump horsepower formula:

Where:

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

Explanation: The formula calculates the theoretical power required to move the fluid, then divides by the pump's efficiency to get actual power needed.

3. Importance of Pump Horsepower Calculation

Details: Proper horsepower calculation ensures correct pump selection, prevents motor overload, and optimizes energy usage in fluid systems.

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.

5. Frequently Asked Questions (FAQ)

Q1: What is typical pump efficiency?
A: Centrifugal pumps typically range from 50-85% efficiency, while positive displacement pumps can reach 90%. Always check manufacturer specs.

Q2: How does specific gravity affect HP?
A: Higher SG fluids require more power - double the SG means double the HP requirement for the same flow and head.

Q3: What's the difference between water and brake HP?
A: Water HP is theoretical power to move fluid. Brake HP includes pump inefficiencies (what the motor must deliver).

Q4: When should I add a safety factor?
A: Add 10-20% safety margin to calculated HP for system uncertainties and future capacity needs.

Q5: Can I use this for viscous fluids?
A: This basic formula works for water-like fluids. For viscous fluids, use viscosity correction charts or specialized calculators.