Isolating branch line for testing
So, I've been reviewing the NFPA code book (thanks a ton, bsperr) and based on the line sizing tables it appears that my existing 1" line from the meter will be large enough for the addition of a fireplace (based on the new line being the longest run - assuming 1/2" w.c. pressure drop w/ less than 2 psi inlet pressure) and I will have to upsize the existing 1/2" line to 3/4" to service the existing range and the new fireplace. Testing requirements state that new branch lines must be pressure tested. I'm trying to figure out how to isolate the new line for testing without putting that pressure on the existing system. Can a new valve be placed at the start of the new line allowing it to be isolated, or is there risk of the valve leaking causing damage to the existing connected appliances? How do you guys isolate these branch lines for testing?