Gas pipe sizing is based on how many factors, and which is an example?

• A. Five factors; for example, maximum gas demand
• B. Six factors; for example, ambient temperature
• C. Seven factors; for example, pipe insulation type
• D. Six factors; for example, allowable loss in pressure

Answer: (D)

Gas pipe sizing uses six factors that influence how large a pipe must be to reliably deliver the required gas to every appliance while keeping pressure within acceptable limits. One concrete example among these factors is the allowable pressure drop (loss) along the piping. Setting a limit on how much pressure can be lost from the source to the farthest appliance ensures the system can meet the lowest-demand scenario without starving any appliance.

Other factors typically considered include the total maximum gas demand (the combined input of all appliances), the supply pressure available at the source, the length of the piping run, the pipe material and its friction characteristics, and the arrangement or number of appliances and branches. By accounting for these six factors, the pipe size is chosen to maintain adequate pressure throughout the system under worst-case conditions. Ambient temperature or pipe insulation type don’t directly set the sizing in this standard approach, so they aren’t treated as primary sizing factors.