Why doesn’t the flame from a propane torch travel back to the can and blow it up?

Question

I’ve always been a little embarrassed to ask, but when I have, say, a propane torch, how come the flame doesn’t go back through the line and blow up the can?

In: Engineering

Answer 1

Fire requires a certain fuel/oxygen mixture to combust. A propane tank has a lot of fuel but little to no oxygen.