The process of gas cutting: refers to preheating the cut metal to the ignition point with gas flame, making it burn violently in pure oxygen flow, forming slag and releasing a lot of heat, and blowing off the oxidized slag under the blowing force of hyperbaric oxygen: the released heat further preheats the next layer of metal to reach the melting point, and finally achieves the purpose of cutting the workpiece.

The process of gas welding: using the flame produced by the mixed combustion of combustible gas and combustion-supporting gas as the heat source, the weldment and welding material are melted at the same time, and then the two are combined between atoms.

2. Preventive measures

(1) oxygen acetylene gas welding gas cutting equipment is strictly prohibited from contacting with grease and dust impurities.

(2) If metal slag or other foreign matter is stained during use, and the wind line is abnormal, the operation should be stopped, and the foreign matter should be cleaned with a special welding nozzle or cutting nozzle, and at the same time, the oxygen valve should be opened to blow out the foreign matter.

(3) When the welding nozzle or cutting nozzle is working, it is forbidden to touch the working face, so as to avoid blocking the air hole, causing oxygen backflow and accidents entering the acetylene system.

(4) When using acetylene pressure reducer, qualified backfire prevention device must be installed to ensure safe and reliable operation.

(5) Oxygen cylinders are forbidden to be used on the ground, and should be placed on shelves or other items. The included angle between oxygen cylinders and the ground plane should be greater than 40.

(6) Use qualified oxygen pressure reducer and acetylene pressure reducer.

(7) The safe distance between oxygen cylinder and acetylene cylinder should be greater than 5m.

(8) Oxygen acetylene gas welding and gas cutting equipment must be used with certificates, or with the guidance and help of effective personnel with experience and special operation certificates.

Extended data:

During gas welding operation, the welding torch is usually held in the right hand, with the thumb at the acetylene switch and the forefinger at the oxygen switch, so as to adjust the gas flow at any time.

The other three fingers hold the torch handle and the right hand holds the welding wire. The basic operations of gas welding are as follows: ignition, flame adjustment, welding and flameout.

When igniting, slightly open the oxygen valve first, then open the acetylene valve, and ignite the flame with an open flame (e.g. electron gun or low-voltage electric spark can be used. ). At this time, the flame is carbonized flame, and then gradually open the oxygen valve to adjust the carbonized flame to neutral flame. If oxygen (or acetylene) increases continuously, an oxidation flame can be obtained.

During ignition, the sound of "shooting" may appear continuously. Because acetylene is impure, it is necessary to release impure acetylene and re-ignite; Sometimes it is difficult to ignite because of too much oxygen, so it is necessary to close the oxygen valve slightly.

When igniting, don't aim the hand holding the fire source directly at the welding nozzle, and don't point at others to avoid burns. When flameout is required after welding, the acetylene valve should be closed first, and then the oxygen valve should be closed to avoid tempering and reduce smoke.

Baidu encyclopedia-gas welding

Baidu encyclopedia-gas cutting