What are the proper steps for pressure testing black iron pipe meant for natural gas? A step by step guide would be amazing! Thanks for any advice.
Some of the things I have already encountered right or wrong
on this subject include:
I can't use my pressure gauges from the garage (needs to be 1/10psi increments)
Flex hoses for appliances need to be disconnected or the ball valve before them must be turned off and/or everything capped
Disconnect on the house side of the main meter (Don't go thru the METER!)
Suggestions of PSI and LENGTH of test recommended are different
Backdrop: I installed a new high efficiency furnace, replaced all the ductwork using proper software and installing dampers on each supply for further system balancing, sidenote: the house used to be one of my mother's rental properties and we had the ductwork cleaned between each tenant-> not worth a dime, absolutely disgusting
. I piped all the new gas line, soapy water method passed flying colors. I bought a Extech ex40 combustible gas sniffer, an existing 1" union on the main line into the house failed the gas sniffer but not the soapy water test. Retightened, let the area air out, passed soapy water failed gas sniffer. Broke down cleaned everything replaced 1" union with new, turned gas on soapy water yes gas sniffer NO! Frustrated but have checked the gas sniffer against other gas lines that passed the soapy water method. So, taking the gas sniffer seriously, it seems to pinpoint the leak very well. I have worked on higher pressure gas line and high pressure city water lines, live taps etc. From what I read, it is more difficult to catch a residential small line leak due to the low psi around 2 or so? Frustrated but moving on to pressure test for piece of mind. Any tips on how to check the pressure would be amazing, I assume I have to evacuate the line of any gas before pressuring with air? When done testing with full lines of air, must the line be purged?