I've had it happen a few times, usually when the can pressure is almost gone and i might touch the tip for a split second (were not changing the gas cans/flasks before completely drained and unusable..... Not my decision!) And always rapidly shut off the gas, wait a few seconds and turn it on again to purge and see if the flame has gone out, it usually spits a black cloud and nothing more and then check everything for heat. I've also heard a coworker doing it several times but they never shut off and just continue using it wondering why the flame is weak before i scream at them to shut it off 🤣 When i started in the company the hoses and whole setup didn't have any flame arrestors! Only backflow preventor, i quickly demanded new hoses, gun and flame arrestors when changing the hoses it where completely black inside the acetylene one..
