1. What is Positive Displacement Pump Flow Calculation?

The positive displacement pump flow calculation determines the volumetric flow rate based on the pump's displacement volume per revolution and its rotational speed. This equation is fundamental for sizing and selecting positive displacement pumps in various industrial applications.

2. How Does the Calculator Work?

The calculator uses the positive displacement pump equation:

Where:

• \( Q_{pdp} \) — Flow rate (m³/s)
• \( V_d \) — Displacement volume per revolution (m³/rev)
• \( N \) — Rotational speed (rev/s)

Explanation: The equation calculates the theoretical flow rate by multiplying the volume displaced per revolution by the number of revolutions per second.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculation is essential for proper pump selection, system design, and ensuring the pump meets the required performance specifications in hydraulic systems and fluid transfer applications.

4. Using the Calculator

Tips: Enter displacement volume in m³/rev and rotational speed in rev/s. Both values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What types of pumps use this equation?
A: This equation applies to all positive displacement pumps including gear pumps, piston pumps, vane pumps, and screw pumps.

Q2: How does efficiency affect the actual flow rate?
A: The calculated value is theoretical flow. Actual flow may be lower due to internal leakage, viscosity effects, and pump efficiency factors.

Q3: Can this equation be used for variable speed pumps?
A: Yes, the equation directly relates flow rate to speed, making it particularly useful for variable speed pump applications.

Q4: What units should I use for displacement volume?
A: While m³/rev is standard, you can use any volumetric unit as long as you maintain consistency throughout the calculation.

Q5: How does fluid viscosity affect the calculation?
A: Higher viscosity fluids may reduce the actual flow rate due to increased internal leakage and higher friction losses, though the theoretical calculation remains the same.