Natural Gas Orifice Size Calculator

Orifice Size Formula:

\[ Orifice\ Size = \frac{BTU}{\sqrt{SG} \times 1355} \]

Orifice Size:

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1. What is the Natural Gas Orifice Size Calculation?

The natural gas orifice size calculation determines the appropriate orifice diameter needed to deliver a specific amount of gas (measured in BTU/hr) based on the gas's specific gravity. This is crucial for proper appliance operation and safety.

2. How Does the Calculator Work?

The calculator uses the orifice size formula:

\[ Orifice\ Size = \frac{BTU}{\sqrt{SG} \times 1355} \]

Where:

\( BTU \) — British Thermal Units per hour (BTU/hr)
\( SG \) — Specific Gravity of the gas
1355 — Constant factor for natural gas calculations

Explanation: The equation calculates the orifice diameter needed to deliver the specified BTU rating while accounting for the density of the gas (through specific gravity).

3. Importance of Orifice Size Calculation

Details: Proper orifice sizing is essential for efficient and safe operation of gas appliances. An incorrectly sized orifice can lead to incomplete combustion, inefficient operation, or potentially dangerous conditions.

4. Using the Calculator

Tips: Enter the BTU rating of the appliance and the specific gravity of the gas. All values must be valid (BTU > 0, SG > 0). Natural gas typically has a specific gravity of about 0.60-0.70.

5. Frequently Asked Questions (FAQ)

Q1: What is specific gravity in natural gas?
A: Specific gravity is the ratio of the density of natural gas to the density of air. It typically ranges from 0.55 to 0.64 for natural gas.

Q2: Why is orifice size important?
A: The orifice controls the flow of gas to the burner. Proper sizing ensures correct air-to-fuel ratio for efficient and safe combustion.

Q3: Can I use this calculator for propane?
A: No, this calculator is specifically designed for natural gas. Propane requires different calculations due to its different properties.

Q4: What are common orifice sizes?
A: Orifice sizes typically range from 0.020 to 0.125 inches, depending on the BTU requirement and gas properties.

Q5: Should I consult a professional for orifice sizing?
A: Yes, gas appliance installation and modification should always be performed by qualified professionals to ensure safety and compliance with local codes.