1. What is the Pump Power Equation?

The pump power equation calculates the required horsepower for a pump based on flow rate, pressure, and efficiency. It's essential for selecting properly sized pumps and motors in fuel systems.

2. How Does the Calculator Work?

The calculator uses the pump power equation:

Where:

• \( Q \) — Flow rate in gallons per minute (GPM)
• \( P \) — Pressure in pounds per square inch (PSI)
• \( \eta \) — Pump efficiency (decimal between 0 and 1)
• 1714 — Conversion factor to get horsepower

Explanation: The equation shows that required power increases with higher flow rates or pressures, and decreases with better pump efficiency.

3. Importance of Pump HP Calculation

Details: Proper horsepower calculation ensures the pump motor isn't undersized (which could lead to failure) or oversized (which wastes energy and increases costs).

4. Using the Calculator

Tips: Enter flow rate in GPM, pressure in PSI, and efficiency as a decimal (e.g., 85% efficiency = 0.85). Typical efficiency for small fuel pumps ranges from 0.5 to 0.85.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical efficiency value for small fuel pumps?
A: Small fuel pumps typically have efficiencies between 50-85% (0.5-0.85). The default value of 0.85 represents a relatively efficient pump.

Q2: Why is the conversion factor 1714?
A: This factor converts (GPM × PSI) to horsepower, accounting for unit conversions and dimensional analysis.

Q3: Does this work for all pump types?
A: This equation works best for positive displacement pumps. Centrifugal pumps may require different calculations as their flow varies with pressure.

Q4: Should I add a safety factor?
A: Yes, it's common practice to add 10-20% to the calculated HP to account for startup loads and other variables.

Q5: How does viscosity affect the calculation?
A: Higher viscosity fluids may reduce pump efficiency, requiring more horsepower than calculated. Specialized equations exist for high-viscosity fluids.