Test pressure to be used shall be no less than 1 ½ times the proposed maximum working pressure, but not less than 10psig. When testing a system having a volume less than 10ft or a system in a single family dwelling, the test duration shall be not less than 10 minutes. Otherwise, test duration shall include an additional 30 minutes for each additional 500 ft of pipe volume, or fraction thereof. Any reduction of test pressure shall be deemed to indicate the presence of a leak. Testing must be repeated after leaks are repaired.
As a reminder, the customer or their installation contractor needs to inspect piping and appliances for leaks immediately after the gas has been turned on.