When performing oxygen cutting operations and backfire occurs, timely measures should be taken to fold and pinch the acetylene hose, and at the same time shut down the gas source urgently. Under normal circumstances, close the acetylene valve first, and then close the acetylene valve. Open the oxygen valve to quickly extinguish the flashback in the cutting torch. Wait for a while, then open the oxygen valve to blow away the remaining gas and particles in the cutting torch, and then ignite again.

When performing gas cutting, you need to pay attention to: the air pressure is stable and does not leak; the pressure gauge, speedometer, etc. are normal and intact; the machine body moves smoothly, and when using the track, it must be straight and vibration-free; the air flow of the cutting nozzle is smooth. No contamination; the angle and position of the cutting torch are accurate.

Extended information:

Backfire must be prevented during gas cutting. The essence of tempering is that the flow rate of oxygen-alkylene mixed gas from the cutting nozzle is lower than the burning speed of the mixed gas, causing backfire. The reasons are:

1. The leather pipe is too long, there are too many joints or the leather pipe is pressed down by heavy objects.

2. If the cutting torch is continuously operated for too long or the cutting nozzle is too close to the steel plate, the temperature of the cutting nozzle will increase, the internal pressure will increase, which will affect the gas speed, and even the mixed gas will spontaneously ignite in the cutting nozzle.

3. The outlet channel of the cutting nozzle is blocked by slag or impurities, and oxygen flows back into the acetylene pipe.

4. The leather hose or the internal pipe of the cutting torch is blocked by debris, which increases the flow resistance.

Baidu Encyclopedia - Oxygen Cutting

Baidu Encyclopedia - Tempering Treatment