I have installed an 1 1/4 underground gas line per code. I am ready for inspection and have installed a pressure gage and pressurized to 20 lbs of air. The pressure holds for 24 hours and then will drop to 8 0r 10 lbs. I have filled it up twice to make sure it will pass inspection but get the same results. Is this typical with temp changes or do I have a leak "every once on awhile"? It doesn't seem to be going down slowly as I check every hour and it hasn't moved. Bad gage? Leak? Help!