1. What is a Differential Pressure to Flow Rate Calculator?

Definition: This calculator estimates the volumetric flow rate through an orifice based on the differential pressure across it.

Purpose: It helps engineers and technicians determine fluid flow rates in piping systems using pressure measurements.

2. How Does the Calculator Work?

The calculator uses the orifice flow equation:

Where:

• \( Q \) — Volumetric flow rate (m³/s)
• \( C \) — Discharge coefficient (dimensionless, typically 0.62 for sharp-edged orifices)
• \( A \) — Cross-sectional area of the orifice (m²)
• \( \Delta P \) — Differential pressure across the orifice (Pa)
• \( \rho \) — Fluid density (kg/m³)

Explanation: The flow rate is proportional to the square root of the pressure difference and inversely proportional to the square root of the fluid density.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate measurement is essential for process control, system design, and equipment sizing in fluid systems.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.62), orifice area in m², pressure difference in Pascals, and fluid density in kg/m³ (default 1000 for water). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical discharge coefficient value?
A: For sharp-edged orifices, it's typically 0.62. For well-rounded entrances, it can approach 0.97.

Q2: How do I convert the flow rate to other units?
A: Multiply m³/s by 1000 for liters/second, or by 3600 for m³/hour.

Q3: What affects the discharge coefficient?
A: Orifice geometry, edge sharpness, Reynolds number, and the β ratio (orifice to pipe diameter ratio).

Q4: Can this be used for gases?
A: Yes, but ensure correct density values for gases and consider compressibility effects at high pressure ratios.

Q5: What's the accuracy of this calculation?
A: It provides theoretical flow. Actual flow may vary ±2-5% depending on installation conditions and calibration.