1. What is Pump kW Calculation?

The Pump kW Calculation determines the power required by a pump to move fluid at a specified flow rate against a given head, accounting for fluid specific gravity and pump efficiency.

2. How Does the Calculator Work?

The calculator uses the pump power formula:

Where:

• \( GPM \) — Flow rate in gallons per minute
• \( Head \) — Total dynamic head in feet
• \( SG \) — Specific gravity of the fluid (dimensionless)
• \( Efficiency \) — Pump efficiency as percentage
• 3960 — Conversion factor (ft-lb/min per HP)

Explanation: The equation calculates the theoretical power required to move the fluid, then divides by pump efficiency to get actual power requirement.

3. Importance of Pump Power Calculation

Details: Accurate pump power calculation is essential for proper pump selection, motor sizing, and energy consumption estimation in fluid systems.

4. Using the Calculator

Tips: Enter flow rate in GPM, head in feet, specific gravity (1.0 for water), and pump efficiency as percentage. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is specific gravity?
A: Specific gravity is the ratio of fluid density to water density at standard conditions (water = 1.0).

Q2: What are typical pump efficiencies?
A: Centrifugal pumps typically range from 40-85% efficiency depending on size and design.

Q3: How does head affect power requirement?
A: Power is directly proportional to head - doubling the head doubles the power requirement.

Q4: What if my flow is in m³/h instead of GPM?
A: Convert m³/h to GPM by multiplying by 4.40287 before using the calculator.

Q5: Why is the 3960 factor used?
A: It converts ft-lb/min to horsepower (1 HP = 33,000 ft-lb/min, and 33,000/8.33 ≈ 3960 where 8.33 is water's weight in lb/gal).