1. What is the Horsepower Formula?

The horsepower formula calculates the power required to pump a liquid based on flow rate, head, specific gravity, and pump efficiency. It's essential for proper pump selection and system design.

2. How Does the Calculator Work?

The calculator uses the horsepower formula:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total dynamic head in feet (ft)
• \( SG \) — Specific gravity of the fluid (dimensionless)
• \( \eta \) — Pump efficiency (decimal, typically 0.5-0.9)
• 3960 — Conversion factor to convert to horsepower

Explanation: The formula accounts for the work needed to move a specific volume of fluid against a given pressure head, adjusted for fluid density and pump efficiency.

3. Importance of Horsepower Calculation

Details: Accurate horsepower calculation ensures proper pump selection, prevents underpowered or oversized pumps, and helps optimize energy efficiency in fluid systems.

4. Using the Calculator

Tips: Enter flow rate in GPM, head in feet, specific gravity (1.0 for water), and pump efficiency (typically 0.7-0.85 for centrifugal pumps). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is total dynamic head?
A: It's the total equivalent height that the pump needs to overcome, including static head, friction losses, and pressure differences.

Q2: Why is specific gravity important?
A: It accounts for fluid density - heavier fluids require more power to pump than water (SG=1.0).

Q3: What's a typical pump efficiency?
A: Centrifugal pumps typically range from 50-85% efficiency, with higher efficiency in larger, well-designed pumps.

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

Q5: How does this differ for viscous fluids?
A: For highly viscous fluids, additional corrections are needed as efficiency decreases with viscosity.