1. What is a Pump Shaft Power Calculator?

Definition: This calculator estimates the mechanical power required at the pump shaft based on fluid flow rate, density, head, and pump efficiency.

Purpose: It helps engineers and technicians determine the power requirements for pump selection and system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_s \) — Shaft power (Watts)
• \( Q \) — Flow rate (m³/s)
• \( \rho \) — Fluid density (kg/m³)
• \( g \) — Gravitational acceleration (9.81 m/s²)
• \( h \) — Head (m)
• \( \eta \) — Pump efficiency (0-1)

Explanation: The formula calculates the power needed to move a fluid at a given rate against a specific head, accounting for pump efficiency.

3. Importance of Shaft Power Calculation

Details: Accurate power calculation ensures proper pump selection, motor sizing, and energy efficiency in fluid systems.

4. Using the Calculator

Tips: Enter the flow rate in m³/s, fluid density (default 1000 kg/m³ for water), head in meters, and pump efficiency (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is pump efficiency?
A: Pump efficiency (η) is the ratio of hydraulic power delivered to the fluid to the mechanical power supplied to the pump shaft, typically 0.5-0.9 for centrifugal pumps.

Q2: How do I convert the result to horsepower?
A: Divide Watts by 746 to get horsepower (1 HP = 746 W).

Q3: What's a typical fluid density?
A: Water is 1000 kg/m³ at 4°C. Oil ranges 800-950 kg/m³, while seawater is about 1025 kg/m³.

Q4: What if I have flow rate in different units?
A: Convert to m³/s (1 L/s = 0.001 m³/s, 1 m³/h ≈ 0.000278 m³/s).

Q5: Does this account for system losses?
A: No, this calculates ideal shaft power. Add 10-20% for safety factors and system losses.