Which of the following is the minimum amount of time required according to NFPA 54 to perform a pressure test on a new gas piping system that has 6 cubic feet of piping in total?

• A. 5 minutes
• B. 10 minutes
• C. 15 minutes
• D. 20 minutes

Answer: (B)

Testing time is based on how much total piping there is to fill with test pressure. The idea is to give enough time for any leaks to show up as a pressure drop, so the system can be declared tight only if the pressure remains steady during the hold period. For a total piping volume of six cubic feet, it falls into the category that requires a ten-minute pressure hold. That duration provides a reliable window to detect leaks without making the test longer than necessary for this size of system. If the volume were smaller (five cubic feet or less), a shorter hold, around five minutes, would be specified; larger volumes would call for longer holds. So the ten-minute minimum is the correct choice for a six-cubic-foot system.