1. What is the Pump Flow Rate Calculator?

Definition: This calculator determines the flow rate of a pump based on horsepower, efficiency, total dynamic head, and fluid density.

Purpose: It helps engineers and technicians size pumps and estimate system performance for various fluid transfer applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM)
• \( HP \) — Pump horsepower
• \( \eta \) — Pump efficiency (0-1)
• \( H \) — Total dynamic head (feet)
• \( \rho_f \) — Fluid density (pounds per gallon)

Explanation: The formula relates pump power to flow rate by accounting for the work needed to move fluid against gravity and friction.

3. Importance of Pump Flow Rate Calculation

Details: Accurate flow rate estimation ensures proper system design, energy efficiency, and prevents pump overload or underperformance.

4. Using the Calculator

Tips: Enter pump horsepower (HP), efficiency (0-1, default 0.8), total dynamic 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: This is a conversion factor that relates horsepower, flow rate, head, and specific gravity in consistent units.

Q2: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 0.5-0.9, with 0.75-0.85 being common for well-designed pumps.

Q3: How do I determine total dynamic head?
A: TDH includes static head (vertical lift) plus friction losses in pipes and fittings. Use head loss calculations for your 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 ≈ 6.8 lb/gal.

Q5: Can this be used for viscous fluids?
A: This formula works best for low-viscosity fluids. For viscous fluids, additional corrections are needed.