1. What is Pumping Horsepower?

Pumping horsepower is the power required to move a fluid through a piping system against the system's total head (pressure). It accounts for flow rate, fluid properties, and pump efficiency.

2. How Does the Calculator Work?

The calculator uses the standard pumping horsepower formula:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total head in feet
• \( SG \) — Specific gravity of fluid (1.0 for water)
• \( \eta \) — Pump efficiency as decimal (0.0-1.0)
• 3960 — Conversion factor (foot-pounds per minute per horsepower)

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

3. Importance of Horsepower Calculation

Details: Proper horsepower calculation ensures you select a pump with adequate power for your application while avoiding oversized, inefficient pumps.

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.

5. Frequently Asked Questions (FAQ)

Q1: What is total head?
A: Total head is the sum of static head (vertical distance), friction head (pipe resistance), and pressure head (system pressure).

Q2: What's a typical pump efficiency?
A: Centrifugal pumps typically range from 50-85% efficiency. Positive displacement pumps can reach 90%.

Q3: Why is specific gravity important?
A: Heavier fluids (SG > 1) require more power to pump than water at the same flow rate and head.

Q4: Should I add a safety factor?
A: Yes, it's common to add 10-20% to calculated HP to account for system variations and future needs.

Q5: What about motor efficiency?
A: This calculation gives brake horsepower. To get motor power, divide by motor efficiency (typically 0.9-0.95).