1. What is Pump Capacity Calculation?

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

Purpose: It helps engineers and technicians size pumps and understand their performance characteristics in fluid systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula relates the mechanical power input to the hydraulic power output, accounting for system head and fluid properties.

3. Importance of Pump Capacity Calculation

Details: Accurate pump capacity estimation ensures proper system design, energy efficiency, and prevents pump overload or underutilization.

4. Using the Calculator

Tips: Enter the pump horsepower, efficiency factor (default 0.85), total head in feet, and fluid density (default 8.34 lb/gal 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 to foot-pounds per minute (1 HP = 3960 ft-lb/min).

Q2: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 0.7-0.9 (70-90%), while positive displacement pumps can reach 0.9-0.95.

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 different fluids, use their specific gravity × 8.34 lb/gal (e.g., 7.48 lb/gal for diesel, 9.8 lb/gal for seawater).

Q5: Can I use this for viscous fluids?
A: This formula works best for low-viscosity fluids. For viscous fluids, additional correction factors are needed.