1. What is Pump Brake Horsepower?

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

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

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

3. Importance of Brake Horsepower Calculation

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

4. Using the Calculator

Tips: Enter the flow rate (GPM), total head (ft), 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: Most centrifugal pumps operate between 50-85% efficiency, with higher efficiency for larger pumps.

Q3: Why is 3960 in the formula?
A: It's a conversion factor that combines unit conversions to give horsepower (1 hp = 550 ft-lb/sec).

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: Should I add a safety factor?
A: Yes, it's common to add 10-20% to the calculated BHP for safety margin and future expansion.