1. What is a Gas Flow Rate Through Orifice Calculator?

Definition: This calculator estimates the volumetric flow rate of gas through an orifice in gallons per minute (GPM equivalent).

Purpose: It helps engineers and technicians determine gas flow rates for system design, analysis, and troubleshooting.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Gas flow rate (GPM equivalent)
• \( C_d \) — Discharge coefficient (dimensionless)
• \( A \) — Orifice area (ft²)
• \( \Delta P \) — Pressure difference across orifice (psi)
• \( \rho_g \) — Gas density (lb/ft³)

Explanation: The formula calculates the theoretical flow rate adjusted by the discharge coefficient and converted to GPM.

3. Importance of Gas Flow Rate Calculation

Details: Accurate flow rate estimation is critical for system design, performance evaluation, and ensuring safe operation of gas systems.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.62 for sharp-edged orifice), orifice area in square feet, pressure difference in psi, and gas density in lb/ft³ (default 0.075 for air at STP).

5. Frequently Asked Questions (FAQ)

Q1: What is the discharge coefficient (C_d)?
A: It's a dimensionless factor that accounts for energy losses in the flow. Typical values range from 0.6-0.9 depending on orifice geometry.

Q2: Why is the result in GPM when it's gas flow?
A: The calculator provides equivalent volumetric flow rate in gallons per minute for comparison with liquid systems.

Q3: What's a typical gas density value?
A: Air at standard conditions is about 0.075 lb/ft³. Other gases vary - hydrogen is 0.0052, natural gas is ~0.045 lb/ft³.

Q4: How do I calculate orifice area?
A: For circular orifices, use \( A = \pi \times (d/2)^2 \) where d is diameter in feet.

Q5: What are the limitations of this calculation?
A: This assumes isothermal, incompressible flow. For high-pressure systems or compressible gases, more complex formulas are needed.