1. What is the Propane Orifice Formula?

The propane orifice formula calculates the diameter of an orifice needed for proper propane flow based on flow rate, pressure drop, specific gravity, and discharge coefficient. Accurate orifice sizing is critical for efficient and safe propane system operation.

2. How Does the Calculator Work?

The calculator uses the propane orifice formula:

Where:

• \( d \) — Orifice diameter (inches)
• \( Q \) — Flow rate (cubic feet per hour, CFH)
• \( C \) — Discharge coefficient (typically 0.8 for propane)
• \( \Delta P \) — Pressure drop (inches of water column)
• \( SG \) — Specific gravity of propane (1.52)

Explanation: The equation balances flow requirements against pressure drop through the orifice, accounting for propane's physical properties.

3. Importance of Orifice Sizing

Details: Proper orifice sizing ensures correct fuel-air mixture, prevents incomplete combustion (sooting), and maintains appliance efficiency and safety.

4. Using the Calculator

Tips: Enter flow rate in CFH, discharge coefficient (default 0.8), pressure drop in inches WC, and specific gravity (default 1.52 for propane). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical discharge coefficient for propane?
A: Most propane orifices use C=0.8, but this can vary from 0.7-0.9 depending on orifice shape and edge conditions.

Q2: How do I measure pressure drop?
A: Use a manometer to measure the pressure difference across the orifice in inches of water column (in WC).

Q3: Why is specific gravity important?
A: Propane's density affects flow characteristics. The standard SG for propane is 1.52 (relative to air=1.0).

Q4: What happens if orifice is too large?
A: Excessive gas flow can cause incomplete combustion, sooting, carbon monoxide production, and potential appliance damage.

Q5: Can this be used for natural gas?
A: No, natural gas has different properties (SG≈0.6). Use a natural gas-specific orifice calculator.