[madmaxx]

You must be a lucky person in life, play the lottery. A company I had worked for buried two people in 8 years. One for nitrogen afixation and the other when an access panel blew apart on a reciprocating compressor and impaled upon his head when the high pressure packing leaked and pressurized the dog house to 30 psig. Then again the access panel was only 3/8" cast iron thick not like your heavy wall manifold you pressured to 150 psig.

Testing with a fluid is exponentially safer since fluid is not compressible. Heck if you are feeling confident do a helium test.