1. What is Pumping Horsepower?

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

2. How Does the Calculator Work?

The calculator uses the pumping horsepower formula:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total dynamic head in feet
• \( SG \) — Specific gravity of fluid (1.0 for water)
• \( \eta \) — Pump efficiency (0-1, typically 0.7-0.9)
• 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 power.

3. Importance of Horsepower Calculation

Details: Proper horsepower calculation ensures correct pump selection, prevents underpowered systems, and helps estimate energy requirements and operating costs.

4. Using the Calculator

Tips: Enter flow rate in GPM, head in feet, specific gravity (1.0 for water), and pump efficiency as a decimal (0.7 for 70% efficiency). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is total dynamic head?
A: It's the total equivalent height that fluid needs to be pumped, accounting for static head, friction losses, and pressure differences.

Q2: What's a typical pump efficiency?
A: Centrifugal pumps typically range from 60-85% efficiency, while positive displacement pumps can reach 90% or higher.

Q3: How does specific gravity affect horsepower?
A: Higher specific gravity fluids require more power - double the SG means double the horsepower needed.

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 horsepower?
A: Motor HP should be equal to or greater than the calculated pump HP, considering service factors and starting conditions.