1. What is Pump Horsepower?

Pump horsepower is the power required to move a fluid at a specified flow rate against a specified head, accounting for the fluid's density and the pump's efficiency. It's a crucial parameter in pump selection and system design.

2. How Does the Calculator Work?

The calculator uses the pump horsepower formula in metric units:

Where:

• \( Q \) — Flow rate (m³/s)
• \( H \) — Head (meters)
• \( \rho \) — Density (kg/m³)
• \( g \) — Gravity (9.81 m/s²)
• \( \eta \) — Pump efficiency (0-1)
• 745.7 — Conversion factor from watts to horsepower

Explanation: The formula calculates the power required to move a fluid by considering the energy needed to overcome elevation and friction losses.

3. Importance of Pump HP Calculation

Details: Accurate horsepower calculation ensures proper pump selection, prevents under/over-sizing, and helps in energy efficiency optimization.

4. Using the Calculator

Tips: Enter flow rate in m³/s, head in meters, density in kg/m³ (1000 for water), and efficiency as a decimal (0.8 for 80%). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between brake HP and water HP?
A: Water HP is the theoretical power needed to move the fluid, while brake HP includes pump inefficiencies (what the motor must actually deliver).

Q2: How does density affect HP requirements?
A: Higher density fluids require more power to pump at the same flow rate and head. HP is directly proportional to density.

Q3: What's a typical pump efficiency?
A: Centrifugal pumps typically range from 40-85% efficiency, with larger pumps generally being more efficient.

Q4: How do I convert to other units?
A: For flow in L/s, divide by 1000; for head in kPa, divide by (ρ×g); for kW, multiply HP by 0.7457.

Q5: Why is the conversion factor 745.7?
A: 1 HP = 745.7 watts, which converts the power from watts (in the numerator) to horsepower.