What is the gas line size for a #8 gas line?

What is the gas line size for a #8 gas line?

• A. 1/2 inch
• B. 1 inch
• C. 3/4 inch
• D. 5/8 inch

Answer: (A)

Gas line sizing uses standard nominal pipe sizes, with a designation like “No. 8” tied to a specific pipe diameter in common piping charts. In residential gas piping, a No. 8 line corresponds to about a 1/2 inch nominal pipe size. That’s why the correct answer is 1/2 inch: the No. 8 designation is historically mapped to a half-inch pipe for typical appliance supply lines. If the run is longer or the appliance requires more gas, a larger diameter would be used, but for many standard residential connections labeled No. 8, the size is 1/2 inch.

Gas line sizing uses standard nominal pipe sizes, with a designation like “No. 8” tied to a specific pipe diameter in common piping charts. In residential gas piping, a No. 8 line corresponds to about a 1/2 inch nominal pipe size. That’s why the correct answer is 1/2 inch: the No. 8 designation is historically mapped to a half-inch pipe for typical appliance supply lines. If the run is longer or the appliance requires more gas, a larger diameter would be used, but for many standard residential connections labeled No. 8, the size is 1/2 inch.