Gas Flow Orifice Calculator

Orifice Flow Equation:

\[ Q = C \times A \times \sqrt{\frac{2 \times \Delta P}{\rho}} \]

Discharge Coefficient (C):

(unitless)

Orifice Area (A):

m²

Pressure Difference (ΔP):

Fluid Density (ρ):

kg/m³

Volumetric Flow Rate (Q):

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1. What is the Orifice Flow Equation?

The orifice flow equation calculates the volumetric flow rate of a gas through an orifice plate based on the pressure difference across the orifice, the orifice characteristics, and the gas properties.

2. How Does the Calculator Work?

The calculator uses the orifice flow equation:

\[ Q = C \times A \times \sqrt{\frac{2 \times \Delta P}{\rho}} \]

Where:

\( Q \) — Volumetric flow rate (m³/s)
\( C \) — Discharge coefficient (dimensionless)
\( A \) — Cross-sectional area of the orifice (m²)
\( \Delta P \) — Pressure difference across the orifice (Pa)
\( \rho \) — Density of the fluid (kg/m³)

Explanation: The equation relates the flow rate through an orifice to the square root of the pressure drop across the orifice, accounting for the orifice geometry and fluid properties.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate measurement is crucial for process control, instrumentation, and system design in various industries including chemical, petroleum, and HVAC.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Typical discharge coefficient for sharp-edged orifices is 0.61. Standard air density is 1.225 kg/m³ at sea level and 15°C.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical discharge coefficient value?
A: For sharp-edged orifices, C is typically about 0.61. The exact value depends on the orifice geometry and Reynolds number.

Q2: How does temperature affect the calculation?
A: Temperature affects gas density (ρ). For accurate results, use the density at the actual operating temperature.

Q3: What are common applications of orifice flow meters?
A: Orifice meters are widely used in natural gas pipelines, chemical plants, and HVAC systems for flow measurement.

Q4: What are the limitations of this equation?
A: The equation assumes steady, incompressible flow and may need corrections for high-velocity compressible flows or non-ideal conditions.

Q5: How do I calculate orifice area for a circular orifice?
A: For circular orifices, A = π × (diameter/2)². Ensure consistent units (diameter in meters gives area in m²).