Question 2: What are the safety precautions for hybrid welding and gas welding? Safety precautions for separate operation of electric welding and gas welding and safety precautions for mixed operation of electric welding and gas welding must be observed:
1. Pay attention to ventilation: especially in narrow space with poor ventilation or limited space slice welding. The gas cylinder should be placed on the upper part of the air inlet.
2. Strict inspection: check valves and joints such as pressure reducing valves and welding torches of gas cylinders to ensure tightness; The primary and secondary wires of electric welding machine are in good contact. The welding parts should not burn the gas pipeline for gas welding, so as to avoid danger caused by gas leakage; Gas welding parts and gas welding shall not touch the welding line. Electric welding machine can't use gas welding parts as grounding wire.
3. Take necessary isolation measures: due to the different nature of electric welding and gas welding, electric welding needs others to protect against ultraviolet radiation and high temperature burns; Gas welding requires others to prevent thermal radiation, harmful gases, dust, etc. When mixing, use a temperature-resistant plate to separate it up and down or back and forth.
4. Special supervision: In case of any situation, take effective measures immediately.
Question 3: What safety precautions should be paid attention to when welding? Before hot work, check around and below to ensure that there are no inflammable and explosive articles. If necessary, clean it first or isolate it effectively.
In case of emergency, fire fighting equipment should be provided on site.
Arrange special personnel to monitor at the scene.
Operators should wear complete personal protective equipment.
Check the construction area after hot work, and leave only after there is no fire hazard.
Safety operation procedures for welders.
1 preparation before work
1. 1 Wear labor protection articles and check whether the equipment and tools used are safe and reliable.
1.2 Make preparations for all work according to the specified requirements, and conduct safety inspection and confirmation on the working environment.
1.3 For aerial work, fasten your seat belt and use it correctly.
1.4 the secondary wire and shell of the welding machine must be well grounded, and the pliers for clamping the electrode should be well insulated.
2 matters in the work
2. 1 welding matters
2. 1. 1 Operators must be familiar with the structure, performance and principle of electric welding machines, master basic welding knowledge and operation skills, and be trained by professionals and operate with certificates.
2. 1.2 Select covered electrode, welding wire and current according to process requirements.
2. 1.3 It is forbidden to weld sealed or pressurized containers. When welding containers containing flammable materials, they should be thoroughly cleaned and ventilated before welding.
2. 1.4 When welding or fusing non-ferrous metals (such as copper, zinc, aluminum, etc.). ) In a closed container, all manholes, exhaust valves, doors and windows must be well ventilated, people should stand at the tuyere, electrical insulation should be kept in good condition, and special personnel should be assigned to monitor outside the container during welding.
2. 1.5 mobile welding machine must cut off the power supply. Welding around inflammable and explosive articles is strictly prohibited. It is forbidden to cut steel plates and bolts by electric welding.
2. 1.6 Before welding, inform the surrounding auxiliary workers to avoid arc light and wear protective glasses when removing rust and slag.
2. 1.7 It is forbidden to work in rainy days, and the safety belt must be fastened when working at height above 2m. Eliminate inflammable and explosive articles around, and electrode tips are not allowed to be thrown around.
2. 1.8 power supply must be cut off in case of work interruption.
2.2 Matters needing attention in gas cutting and gas welding
2.2. 1 Operators must master the basic knowledge and skills of gas welding, and can only operate after professional training.
2.2.2 Check whether the barometer and pressure reducing valve are in good condition and effective before operation.
2.2.3 When handling oxygen cylinders, safety caps must be worn, and the dry tempering safety device should be sensitive and reliable. Check that the bottle mouth is not allowed to leak, and it is not allowed to be placed by the fire.
2.2.4 When gas welding is used for hot work, the oxygen acetylene cylinders should be placed separately, with a distance of not less than 5m and a distance of not less than10m from the fire source. It is strictly forbidden to put it under high-voltage lines and suspenders. Oxygen acetylene bottles should be strictly exposed to the scorching sun. In winter, the bottles will freeze, and they should be carefully baked and hammered.
2.2.5 It is forbidden to cut and weld pressure vessels or appliances containing inflammable and explosive articles.
2.2.6 Turn on acetylene when opening the gas, turn off oxygen when closing the gas, and blow with oxygen to prevent backfire. When cutting the iron plate, the iron plate should be erected, and the cushion block that destroys the ground should be fortified below the cutting material.
2.2.7 When cutting iron plates over 30mm, drill holes before cutting.
2.2.8 When welding containers, clean them with clear water first, and then weld them after ventilation.
2.2.9 It is forbidden to use oxygen instead of compressed air. For example, when blowing acetylene pipe with oxygen, you must wait for the gas to run away and smell acetylene before igniting to avoid backfire and explosion.
2.2. 10 often clean the oxygen pipe and acetylene pipe with alkaline water, and handle it in time if it is damaged.
3 Cleaning after work
3. 1 Put away the welding pipeline and clean up the welding site.
3.2 Clean up the coating of the welded workpiece, put it in order, and dump the nonmetallic waste in the designated place.
I hope I can help you.
Question 4: What safety precautions should be paid attention to in electric welding operation: Electric welding is a special operation, and welders must hold relevant certificates; Power control should use automatic switch, and manual switch is not allowed; The primary and secondary lines must be equipped with electric shock protection devices; The length of the primary line is less than 5m, and the floor cannot be mopped; The length of the secondary line should be less than 30m, the wiring should be firmly crimped, and a protective cover should be installed; Special cable shall be used for the handle of electrode holder, with double wires in place, no joint and no damage to insulation; Metal scaffolding, rails and structural steel bars shall not be used as annular grounding wires. The above contents are compiled according to the problems encountered by the students in their actual work for reference. If in doubt, please communicate and correct in time.
Question 5: What 1? Should we pay attention to the safety requirements of electrode holder and welding gun (1) in electric welding? Lightweight structure and convenient operation. The weight of hand arc welding tongs shall not exceed 600g, and national standard products shall be adopted. (2) Good thermal insulation performance and thermal insulation capacity. The handle should have a good heat insulation layer to prevent it from getting hot and hot. The welding torch head of gas shielded welding shall be protected by heat insulation material. The joint of the electrode holder from the clamping rod to the handle (3) The connection between the electrode holder and the welding gun and cable must be simple and reliable, and the joint must not be exposed to prevent electric shock. Stop. The spacing is150 mm. (4) The plasma torch shall ensure that the water cooling system is sealed. No air leakage, no water leakage (5) The hand arc electrode holder should be able to ensure that the covered electrode can be clamped at any inclination, which is convenient for replacement. 2. Safety requirements for welding cables Welding cables are insulated wires connecting welding machines, electrode holders (guns) and weldments. , and shall meet the following safety requirements: (1) The welding cable shall have good conductivity and insulating outer layer. Generally, it is made of copper core (multi-strand thin conductor) wrapped with rubber insulating sleeve, and the insulation resistance is not lower than 1Mn. (2) It is light and flexible, can be bent and twisted at will, and is easy to operate. (3) Welded cables shall have good mechanical damage resistance, oil resistance, heat resistance and corrosion resistance. (4) The length of welding cable shall be determined according to specific conditions. If it is too long, the pressure drop increases, and if it is too short, it is inconvenient to work. Generally, the cable length is 20-30m. (5) It has an appropriate cross-sectional area. The cross-sectional area of welding cable should be selected according to welding current. To ensure that the conductor will not overheat and burn the insulation layer. See the table below for the cross section and maximum current of the cable. Cable cross-section and maximum current conductor cross-section area (mm2) Single strand 25 50 70 95 Double strand 2× 16 2×25 2×35 Maximum current (A) 200 300 450 600 (6) If the whole welded cable is used, there should be no joint in the middle. If it is necessary to use short wires for extension, the number of joints shall not exceed 2. When the cable is extended, it should be firmly connected with the connector, and the joint should be well insulated. (7) It is forbidden to use the metal institutions, pipes, tracks or other metal laps in the workshop as wires. (8) The welding cable shall not be placed next to the hot welding metal near the arc to avoid burning the insulation layer. At the same time, rolling wear should be avoided. Welding cables are prohibited from contacting flammable substances such as oil and grease. (9) Copper (or aluminum) wire nose must be used for the connection between welding cable and welder, so as to avoid the secondary terminal board burning out and causing fire. (10) The insulation of welding cables should be checked regularly every six months. (1 1) Due to the high voltage, the length of the power cord connected between the welder and the switchboard shall not exceed 3m except for good insulation. If long wires are really needed, interval safety measures should be taken, that is, porcelain bottles should be laid along the wall above 2.5m from the ground. It is forbidden to lay the power cord along the ground, and don't fall into muddy water. 3. Safety requirements for the use of welding tools In order to prevent electric shock accidents, in addition to wearing protective overalls, protective gloves and insulating rubber shoes as required, it should also be kept dry and clean. In the process of operation, we should also pay attention to the following aspects. (1) Before welding, first check whether the welder and tools are in good condition, safe and reliable. For example, whether the insulation between the electrode holder and the welding cable is damaged, whether the welding machine shell is grounded, and whether the welding machine connection point is in good contact. No work shall be started without safety inspection. (2) When working in a narrow space, a boathouse, a container or a pipeline, insulating shoes must be worn to prevent electric shock, and rubber sheets or other insulating pads must be placed under the feet; They'd better take turns to work in order to take care of each other. Otherwise, it is necessary to have a guardian to pay attention to the safety of the operator at any time, and cut off the power supply immediately for rescue in case of danger. (3) When the clothes are wet after sweating, don't lean on the charged steel plate or workpiece to prevent electric shock. (4) When the workplace is wet, the ground should be covered with rubber sheets or other insulating materials. (5) Replace covered electrode with leather gloves, and do not operate with bare hands. (6) During live working, for the sake of safety, the electrode holder shall not be clamped under the armpit to move the workpiece to be welded or the welding cable shall be hung around the neck. (7) When pushing the switch knife switch, the face is not allowed to face the switch, so as to prevent the sparks generated by short circuit from burning the face. (8) The following operations can only be carried out after the power supply is cut off: when replacing the welding machine joint; When it is necessary to connect the secondary circuit to replace the weldment; When replacing the safety device; When the welding machine fails and needs maintenance; When the welding machine is removed from the working place; Finish work or leave the job site temporarily.