1. What is Centrifugal Pump Flow Rate Calculation?

Definition: This calculator determines the flow rate (in gallons per minute) of a centrifugal pump based on power input, efficiency, total head, and fluid density.

Purpose: It helps engineers and technicians design and evaluate pump systems for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( HP \) — Horsepower input to the pump
• \( \eta \) — Pump efficiency (0-1)
• \( H \) — Total dynamic head (feet)
• \( \rho \) — Fluid density (pounds per gallon)

Explanation: The formula relates the power input to the hydraulic power output, accounting for pump efficiency and system head.

3. Importance of Pump Calculations

Details: Accurate flow rate calculations ensure proper pump selection, energy efficiency, and system performance in applications like water supply, HVAC, and industrial processes.

4. Using the Calculator

Tips: Enter the pump horsepower (HP), efficiency (0-1, default 0.85), total head in feet, and fluid density in lb/gal (default 8.34 for water). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the constant 3960 in the formula?
A: It's a conversion factor that equates horsepower (550 ft-lb/sec) to the units used in pump calculations (GPM, ft head, lb/gal).

Q2: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 60-85% efficiency, with higher efficiency for larger, well-designed pumps.

Q3: How do I determine total dynamic head?
A: Total head includes static head, friction losses, and pressure differences in the system.

Q4: What density should I use for other fluids?
A: For other fluids, use their specific weight divided by 7.48 (gal/ft³). Example: SAE 30 oil is ~7.0 lb/gal.

Q5: Can this be used for other pump types?
A: This formula is specific to centrifugal pumps. Positive displacement pumps require different calculations.