A gas branch must deliver 55 cfh of natural gas over a 60 ft longest length. The sizing table for that length gives these capacities: 1/2 in = 42 cfh, 3/4 in = 88 cfh, 1 in = 165 cfh. What is the minimum pipe size?

Explanation

The 55 cfh demand exceeds the 42 cfh capacity of 1/2 in pipe at 60 ft, so the next size up, 3/4 in (88 cfh), is required. Gas pipe is sized on the longest length from the meter to the most remote outlet, applied to every section. A 1/2 in pipe would be overloaded and starve the appliance.