1. What is the Pump Power Equation?

The pump power equation calculates the required motor size based on flow rate, head, fluid density, and pump efficiency. It's essential for selecting properly sized pumps to avoid under- or over-sizing.

2. How Does the Calculator Work?

The calculator uses the pump power equation:

Where:

• \( P \) — Power (kW)
• \( Q \) — Flow rate (m³/h)
• \( H \) — Head (meters)
• \( \rho \) — Density (kg/m³)
• \( g \) — Gravity (9.81 m/s²)
• \( \eta \) — Pump efficiency (0-1)

Explanation: The equation calculates the hydraulic power needed to move the fluid, then accounts for pump efficiency to determine actual motor power required.

3. Importance of Proper Motor Sizing

Details: Correct motor sizing ensures energy efficiency, prevents premature motor failure, and maintains optimal pump performance. Oversized motors waste energy while undersized motors may fail prematurely.

4. Using the Calculator

Tips: Enter flow rate in m³/h, head in meters, fluid density (1000 kg/m³ for water), and pump efficiency (typically 0.7-0.9). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 0.7-0.9 (70-90%), but check manufacturer specifications for exact values.

Q2: How do I account for system losses?
A: Either reduce the efficiency value or add 10-20% safety factor to the calculated power.

Q3: What if my fluid isn't water?
A: Enter the correct density for your fluid (e.g., 800 kg/m³ for diesel, 13600 kg/m³ for mercury).

Q4: Should I round up the motor size?
A: Yes, motors are typically available in standard sizes, so round up to the nearest available size.

Q5: What about NPSH requirements?
A: This calculator determines power only. Net Positive Suction Head must be calculated separately.