What would be the capacity in cubic feet of gas per hour for a gas pipe installation using Schedule 40 metallic pipe with a pressure drop of 0.5 in. W.C.?

To determine the capacity in cubic feet of gas per hour for a gas pipe installation, several factors need to be taken into consideration, including the diameter of the Schedule 40 metallic pipe and the pressure drop specified. Schedule 40 metallic pipes have specific flow characteristics and tables that outline the capacity based on pressure drop and other parameters.

Given a pressure drop of 0.5 inches of water column (W.C.), it is possible to reference standard gas flow tables for Schedule 40 pipes to determine the gas flow capacity. These tables provide cubic feet per minute (CFM) values based on the pressure drop across a specific pipe size.

The correct answer indicates a flow capacity of 72 CFM, which is consistent with typical values for a medium-sized Schedule 40 pipe given a 0.5 in. W.C. pressure drop. This flow capacity is suitable for common residential or light commercial applications where gas usage is moderate.

Utilizing this approach, one can accurately assess the flow capacity for various pipe sizes and pressure drops, making it essential for ensuring proper sizing of gas piping systems in HVAC installations.