gas line pressure test

Old 11-15-18, 07:31 AM
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gas line pressure test

I am finishing my basement and installing 3 new gas lines for range, gas fireplace and outdoor grill. I have all the lines run, but have not yet connected into the existing service at the house. I am pressure testing all the new work first and it does hold 15 psi for 15 minutes. It will even hold 15 psi for 3 hours, but when I check it the next day, the pressure is down to almost 0. To me, I would assume it would hold the pressure indefinitely. When I bubble test, I can't find anything.

Is this expected behavior, and thats why the inspectors will only look at the 15 minute test?
Old 11-15-18, 03:08 PM
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The pressure will vary greatly based on the temperature.
Old 11-17-18, 10:10 AM
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Is it steel pipe or csst? If it's steel (and not connected to anything) pump it up to 100 psi (or whatever you can manage) then spray. I don't know what the max would be for csst. Note that a plumbing supplier will carry bubble stuff that lasts longer than dish soap (doesn't evaporate as quickly).

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