1. What is Pump Horsepower Calculation?

The pump horsepower calculation determines the power required to move fluid through a system at a specified flow rate against a given head pressure, accounting for fluid properties and pump efficiency.

2. How Does the Calculator Work?

The calculator uses the pump horsepower equation:

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 (decimal from 0 to 1)
• 3960 — Conversion factor

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

3. Importance of Proper Pump Sizing

Details: Correct pump sizing ensures efficient operation, prevents energy waste, reduces maintenance costs, and extends equipment life. Oversized pumps waste energy while undersized pumps can't meet system demands.

4. Using the Calculator

Tips: Enter flow rate in GPM, 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 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 70-90% efficiency, while positive displacement pumps can be 80-95% efficient.

Q3: Should I add a safety factor?
A: Yes, it's common practice to add 10-20% to the calculated horsepower for safety margin and future needs.

Q4: How does viscosity affect pump sizing?
A: Higher viscosity fluids require more power and may reduce pump efficiency. Special corrections are needed for viscous fluids.

Q5: What about motor efficiency?
A: This calculation gives hydraulic horsepower. To determine electrical power needs, divide by motor efficiency (typically 0.85-0.95).