Why in gas stove gas does not spread despite there is no barrier after nozzle and instead goes straight?

Question

Gas goes to burner and burn there instead of spreading near nozzle

Answer 1

Career has it almost right. However, gas will not burn with oxygen. Pure gas leaves the nozzle by the air inlet ports. Between there and the burner, the air and gas mix to form a combustible mixture. When lit, it burns at the burner.

Why doesn't the flame travel down the tube toward the nozzle? Two reasons. The air/gas mixture is traveling at a speed faster than the flame can. Also the air/gas mixture is cooled in the tube, so flame cannot propagate. Sometimes a little pop is heard when the gas is turned off. When this happens, the tube doesn't cool the mixture and it burns in the tube. It is an almost explosion, called a deflagration, rather than a detonation.

Answer 2

I'm not sure I understand your question fully, but if it what I think it is, it is because gas is under pressure, and has to mix with Oxygen first to burn. Gas will burn without O2, but it is more of an explosive element, and under pressure, it needs to slow down in the air to combust as it is being shot out.