1. What is Positive Displacement Pump?

A positive displacement pump makes a fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe. These pumps give a constant flow rate regardless of pressure.

2. How Does the Calculator Work?

The calculator uses the positive displacement pump equation:

Where:

• \( Q \) — Flow rate (m³/s)
• \( V \) — Displacement volume per revolution (m³/rev)
• \( n \) — Pump speed (rev/s)

Explanation: The flow rate is directly proportional to both the displacement volume and the pump speed.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculation is essential for system design, pump selection, and ensuring proper operation of hydraulic systems.

4. Using the Calculator

Tips: Enter displacement volume in m³/rev and pump speed in rev/s. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What types of pumps use this equation?
A: Gear pumps, piston pumps, diaphragm pumps, lobe pumps, and other positive displacement pump types.

Q2: Does viscosity affect the flow rate?
A: While viscosity affects power requirements, it doesn't significantly affect the theoretical flow rate in positive displacement pumps.

Q3: What is volumetric efficiency?
A: The ratio of actual flow rate to theoretical flow rate, accounting for internal leakage and other losses.

Q4: How does pressure affect the flow rate?
A: In ideal positive displacement pumps, flow rate is independent of pressure, though in reality there may be slight decreases at higher pressures.

Q5: What are common applications?
A: Hydraulic systems, chemical dosing, fuel injection, food processing, and other applications requiring precise flow control.