Gas Pipe Sizing Calculator

Gas Pipe Sizing Formula:

\[ Dia = \sqrt{\frac{Flow \times Length \times Factor}{Pressure\ Drop}} \]

Flow Rate:

CFH

Pipe Length:

Gas Factor:

Custom Factor Value:

Pressure Drop:

in WC

Pipe Diameter:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Gas Pipe Sizing?

Gas pipe sizing is the process of determining the appropriate diameter for gas piping systems to ensure adequate gas flow while maintaining proper pressure levels. Proper sizing is essential for efficient and safe operation of gas appliances.

2. How Does the Calculator Work?

The calculator uses the gas pipe sizing formula:

\[ Dia = \sqrt{\frac{Flow \times Length \times Factor}{Pressure\ Drop}} \]

Where:

\( Dia \) — Pipe diameter (inches)
\( Flow \) — Gas flow rate (CFH - Cubic Feet per Hour)
\( Length \) — Pipe length (feet)
\( Factor \) — Gas factor (0.003 for natural gas)
\( Pressure\ Drop \) — Allowable pressure drop (inches WC)

Explanation: This formula calculates the minimum pipe diameter required to deliver the specified gas flow while maintaining the desired pressure drop across the pipe length.

3. Importance of Proper Pipe Sizing

Details: Correct gas pipe sizing ensures adequate gas supply to appliances, prevents pressure drops that can cause appliance malfunction, and maintains system safety by preventing excessive pressure buildup.

4. Using the Calculator

Tips: Enter flow rate in CFH, pipe length in feet, select gas type or enter custom factor, and specify allowable pressure drop in inches WC. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is CFH in gas flow measurement?
A: CFH stands for Cubic Feet per Hour, which measures the volume of gas flowing through the pipe per hour at standard conditions.

Q2: Why is the gas factor 0.003 for natural gas?
A: The factor 0.003 is derived from the specific gravity and flow characteristics of natural gas, accounting for its density and viscosity in pipe flow calculations.

Q3: What is a typical pressure drop for gas piping?
A: Typical pressure drops range from 0.3 to 0.5 inches WC for most residential applications, but specific requirements may vary based on local codes and appliance specifications.

Q4: Can this calculator be used for propane gas?
A: For propane gas, a different factor should be used. Consult gas piping tables or engineering references for appropriate factors for different gas types.

Q5: Are there code requirements for gas pipe sizing?
A: Yes, gas pipe sizing must comply with local building codes and standards such as NFPA 54 (National Fuel Gas Code) or equivalent regional regulations.