1. What is the Natural Gas Orifice Equation?

The Natural Gas Orifice equation estimates flow rate through an orifice based on pressure difference, specific gravity, and a flow coefficient. It's commonly used in gas measurement and control applications.

2. How Does the Calculator Work?

The calculator uses the orifice flow equation:

Where:

• \( Q \) — Flow rate (units depend on K)
• \( K \) — Flow coefficient (dimensionless)
• \( \Delta P \) — Pressure difference across orifice (psi)
• \( SG \) — Specific gravity of gas (relative to air)

Explanation: The equation shows that flow is proportional to the square root of the pressure difference times the specific gravity.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation is crucial for gas measurement, control system design, and safety calculations in natural gas systems.

4. Using the Calculator

Tips: Enter the flow coefficient (K), pressure difference in psi, and specific gravity (default is 0.6 for natural gas). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical K value?
A: K values vary by orifice design but typically range from 0.6 to 0.8 for standard orifice plates.

Q2: What is specific gravity of natural gas?
A: Typically 0.6-0.7 relative to air (1.0), but varies with gas composition.

Q3: What units does Q have?
A: The units depend on the units used in K. Common units include SCFH (standard cubic feet per hour) or m³/h.

Q4: What are limitations of this equation?
A: Assumes turbulent flow, incompressible flow, and no significant temperature changes. Not valid for very low pressure differences.

Q5: How accurate is this calculation?
A: For well-characterized orifices and within normal operating ranges, accuracy is typically ±1-2%.