1. What is Water Pump Horsepower?

Water pump horsepower is the power required to move a specific volume of fluid against a given head (pressure) at a certain efficiency. It's crucial for selecting the right pump motor size for your application.

2. How Does the Calculator Work?

The calculator uses the water pump horsepower formula:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total head in feet
• \( SG \) — Specific gravity of the fluid (1 for water)
• \( \eta \) — Pump efficiency as a decimal (0-1)
• 3960 — Conversion factor to convert to horsepower

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

3. Importance of Pump Horsepower Calculation

Details: Proper horsepower calculation ensures you select a pump that can handle your flow and head requirements without being oversized (wasting energy) or undersized (failing to meet demand).

4. Using the Calculator

Tips:

• Flow rate: Measure or estimate your required GPM
• Head: Include all vertical lift and friction losses
• Specific gravity: 1 for water, higher for denser fluids
• Efficiency: Typical centrifugal pumps are 50-85% efficient

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between brake horsepower and water horsepower?
A: Water horsepower is the theoretical power needed to move the water. Brake horsepower includes pump inefficiencies (what the motor must actually deliver).

Q2: How do I account for friction loss in the head calculation?
A: Add the equivalent feet of head caused by pipe friction to your vertical lift. Use friction loss tables or calculators for your pipe size and flow rate.

Q3: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 50-85% efficiency. Higher for larger, well-designed pumps; lower for small or worn pumps.

Q4: How does viscosity affect horsepower requirements?
A: Higher viscosity fluids require more power. Use viscosity correction factors or specialized formulas for non-water fluids.

Q5: Should I add a safety factor to the calculated horsepower?
A: Yes, it's common to add 10-20% to account for system variations and future demands, but avoid excessive oversizing which reduces efficiency.