What is the gas line size for a #4 gas line?

What is the gas line size for a #4 gas line?

• A. 1/2 inch
• B. 3/4 inch
• C. 1 inch
• D. 1 1/4 inch

Answer: (C)

Gas line size is determined by a standard chart that maps a gas line designation to a specific pipe diameter. A No. 4 gas line corresponds to 1 inch nominal pipe size, which is why the correct choice is 1 inch. This designation system matters because the pipe diameter directly affects how much gas can be delivered and the pressure drop along the run. Smaller sizes like 1/2 inch or 3/4 inch have lower capacity and are used for lighter loads, while 1 1/4 inch is larger than what No. 4 typically designates.

Gas line size is determined by a standard chart that maps a gas line designation to a specific pipe diameter. A No. 4 gas line corresponds to 1 inch nominal pipe size, which is why the correct choice is 1 inch. This designation system matters because the pipe diameter directly affects how much gas can be delivered and the pressure drop along the run. Smaller sizes like 1/2 inch or 3/4 inch have lower capacity and are used for lighter loads, while 1 1/4 inch is larger than what No. 4 typically designates.