The one linked above is aluminum, so it's not only sparkless, it's also doesn't rust.
Had an HVAC guy check for leaks in a residential gas line with a lighter. Same thought process, smaller scenario.
Still made me suck underwear up my butt when he did it the first time.
It was inside, natural gas, afterwards he talked about being almost smell blind from the years he has been around it, and it scared the crap out of me.
Pipe big enough to walk thru.... no thanks.