Since the invention and popular use of the gas barbecue, many urban myths have flourished, popularized by bizarre, but widely publicized stories of explosions, fires, and injuries. Every time my BBQ ‘kicks’ my wife runs inside convinced the BBQ is about to explode and take half our apartment block with it.
Recoil? Gas barbecues and many other gas stoves operate with little to no noise, and yet a loud ‘pop’ is occasionally heard before the sound of gas rushing like a torch. If you look under your barbecue, you’ll see that the flame from your gas burner has migrated from the correct openings along or above the flame ring or “burner” as some call it; to a violent torch-like flame originating in the gas-air mixing chamber where the gas connection is first connected to the flame ring or burner. This is the point where my wife makes her emergency exit and heads for the hills, despite my reassurances.
Here is the common mistake. The gas flame for some reason transferred to the mixing chamber and because it now resembles a flamethrower the uninformed and natural opinion is that the flame will now burn back inside the LPG hose in the LPG cylinder. LPG causing a catastrophic explosion worthy of CNN News helicopter coverage and response from four fire trucks.
No, he will not. Two things prevent that from happening. First of all, there’s a net outflow of gas from your cylinder, which is why the improperly burning flame sounds so fierce. Second, inside the gas hose is fair gas (LPG); no air LPG is flammable between 2% and 9% concentration in air. That is a very narrow flammability range. Have you ever tried to light the gas burner above the stove and the gas seems to be coming out at an alarming rate and the piezo on the stove clicks and sparks but the gas still won’t ignite? burn. The same goes for the gas hose that connects the gas cylinder to the gas barbecue.
So what should I do? Calmly determine which of the burners under your grill is the offending burner and turn it off. You will hear the same ‘pop’ as the flame goes out now that the gas has stopped flowing. Then turn the gas back on and light the burner as normal and continue cooking your lunch or dinner. Oh, you may also have to go find your wife or friends from wherever they are hiding and assure them that dinner is served.