Welding/cutting in room with gas meter

[Kayos]

I’m sure grandfather told me he used to test for leaks in gas line with a flame! He used to work on the gas holders for british gas (or whatever it used to be) from the end of the war through to the late 70’s.

Town/coal gas that was the approved method

Much lower flame speed than natural gas, it just flared up but couldnt sustain itself

 

[the artfull-codger]

Ammonia in the washing up liquid attacks the pipe.
I suspect in your application they were cleaned thoroughly, not always possible on a pipe. It is also not an approved method of finding a leak, it's for location confirmation only
Many documented cases of pipe pin holding and washing up liquid was always the cause

The Gas Safety (installation and use) regulations forbid its use so it's a non argument anyway, a big bottle of LDF is £4, I always have a couple in my box

Aah thanks for that & yes they were cleand afterwards, apparently the ammonia in the horses urine in the horse artillery caused cracks in the brass shell cases as well.