1. What is Pump Brake Horsepower?

Definition: Brake horsepower (BHP) is the actual horsepower delivered to the pump shaft, representing the power required to drive the pump.

Purpose: It helps engineers and technicians properly size pumps and motors for fluid systems.

2. How Does the BHP Equation Work?

The calculator uses the formula:

Where:

• \( BHP \) — Brake horsepower
• \( Q \) — Flow rate (gallons per minute, GPM)
• \( H \) — Total head (feet)
• \( \rho \) — Fluid density (pounds per gallon, lb/gal)
• \( \eta \) — Pump efficiency (decimal, 0-1)

Explanation: The equation calculates the power required to move a specific fluid at a given flow rate against a certain head pressure, accounting for pump efficiency.

3. Importance of BHP Calculation

Details: Accurate BHP calculation ensures proper pump selection, prevents motor overload, and optimizes energy consumption in fluid systems.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between BHP and WHP?
A: Brake horsepower (BHP) is power at the pump shaft, while water horsepower (WHP) is power delivered to the fluid. BHP accounts for pump inefficiencies.

Q2: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 50-85% efficiency, while positive displacement pumps can reach 90% or more.

Q3: Why is 3960 in the denominator?
A: This is a conversion factor that results from combining unit conversions to give BHP in horsepower when using GPM, feet, and lb/gal.

Q4: How do I find total head (H)?
A: Total head is the sum of static head, friction head, and pressure head in the system.

Q5: What if my fluid isn't water?
A: Adjust the density (ρ) value accordingly. For example, gasoline is about 6.0 lb/gal, while brine might be 8.5-9.5 lb/gal.