How dangerous is welding? These dangerous red lines can’t be touched!

1n recent years, welding and cutting operations are becoming more and more frequent in the production operations, building demolition and maintenance projects. Fire, explosion and other accidents caused by illegal welding operations occur frequently

accident case 1

the welder connected the power supply of the welder without permission and suffered electric shock

the main cause of the accident is that a welder in a factory carried out welding operation at the outdoor temporary construction site. During the operation, he found that there was no power switch box when the welder was connected, so he de electrified the rubber at the head of each wire on the cable and connected it to the outdoor power grid. However, due to the wrong connection of the zero wire to the live wire, when he adjusted the welding current and touched the shell with his hand, he suffered an electric shock and died

the main cause of the accident is that the welder is not familiar with the relevant electrical safety knowledge and wrongly connects the zero line to the live line, which leads to the electrification of the welding machine shell and the death of electric shock

how to prevent accidents

wiring work must be carried out by electricians, and welders are not allowed to do it without authorization

accident case 2

when replacing the welding rod, she touched the welding tongs with her hand and suffered electric shock

the main cause of the accident was that a young female welder in a shipyard was doing welding work in the cabin. Because of the high temperature in the cabin and poor ventilation, she was sweating a lot, so she soaked her work clothes and gloves. When changing the electrode, he touched the welding tongs and suffered electric shock. When he just suffered from electric shock, he fell backward because of spasm, but the welding tongs accidentally fell on his neck. Finally, the rescue failed and he died< (1) the no-load voltage of the welding machine is higher than the safe voltage (2) the temperature in the cabin is high, the welder sweats a lot, the resistance of the human body is reduced, and the risk of electric shock is increased (3) the electric shock is not found in time, and help is needed in time, so the current through the human body lasts for a long time, The heart and lung and other important organs were seriously damaged, and the rescue was ineffective< How to prevent similar accidents (1) ventilation device should be set up during cabin operation to make the air convection and avoid high internal temperature (2) during cabin operation, a guardian must be present to pay attention to the working status of welders at any time. 1n case of dangerous license, switch on immediately to save people accident case 3 wiring board burned, The electric shock accident caused by the electrification of the welding machine shell the main process of the accident – the welder of a factory, Party A and Party B were carrying out the iron shell spot welding operation, and found that a section of lead coil of the welding machine had been broken, so electrician a found a section of flexible wire and asked electrician B to replace it. When Party B changed the line, he found that the bolt of the primary line connecting plate was loose, so he tightened it with a wrench. At this time, Party A was not present. Then Party B left the operation site after a few trial welding. After party a returned, he began to spot weld without knowing the situation, and he fell to the ground with a loud cry. Worker C immediately switched off the power supply, but finally died because the rescue was not timely the main causes of the accident – (1) due to the burning of the wiring board, the coil and the welding machine shell want to touch, causing a short circuit (2) the welding machine shell is not grounded how to prevent the accident (1) the equipment should be repaired by electricians (2) the welding equipment should be protected from grounding accident case 4 when the welder was working in the container, the fire was caused by oxygen replacement the main cause of the accident was that the machine repair welder of a pesticide factory was welding the baffle in a breeding pot with a diameter of one meter and a height of two meters, This equipment is not equipped with smoke exhaust equipment, so the welder uses oxygen to disperse the smoke in the pot. However, when the welder entered the pot again for welding operation, he only heard a “boom”, and a fire broke out. The burn area of the welder exceeded 80%, and the third degree burn accounted for 60%. He died seven days after rescue the main cause of the accident – (1) using oxygen as ventilation source is a serious violation of regulations (2) entering the vessel for welding without ventilation device how to prevent the accident (1) ventilation device should be set when entering the vessel for welding operation (2) the ventilation gas source should be compressed air accident case 5 the decompressor of the oxygen cylinder was on fire and burnt out the main process of the accident is that the gas welder of a construction team used a leaking welding torch during welding operation, The welder’s palm was burned and frothed by the torch sprout from the regulating wheel. After applying badger oil, he continued to work. During the welding process, tempering occurred again, the oxygen hose exploded, the pressure reducer caught fire and burned. When the oxygen cylinder valve was closed, the upper part of the oxygen cylinder was very hot and dangerous the main cause of the accident is that the leaking torch is very easy to backfire; 1n addition, when adjusting the oxygen pressure, open the oxygen cylinder valve and pressure reducer; 1n addition, grease is stuck on the pressure vessel, resulting in tempering, which causes severe combustion under the strong oxidation of compressed pure oxygen accident prevention measures – (1) before gas welding, it is necessary to check whether the welding torch is in good condition, and it is strictly prohibited to use if gas leakage is found, and welding can be continued after repair< (2) do not use gloves with grease to open the oxygen cylinder valve and pressure reducer accident case 6 the fire site did not meet the requirements and ignited the fire the main process of the accident – Gu, a welder from a shipyard, applied to the firemen on board for fire work, but the firemen approved the fire work before they arrived at the site. After Gu’s gas cutting, the oil on the bottom of the ship was splashed with sparks and ignited a raging fire. The personnel on the scene failed to put out the fire with water and fire extinguishing agent, resulting in five deaths, one serious injury and three minor injuries< The main causes of the accident are as follows: (1) firefighters neglect their duties and blindly approve the fire work before they arrive at the scene< (2) there is oil under the hot work part< (3) the fire-fighting knowledge of on-site personnel is lack how to prevent accidents (1) after receiving the application report, firemen should go deep into the scene to check and confirm the safety before starting the fire permit (2) it is necessary to clear the oil under the hot work part (3) strengthen the safety knowledge learning of employees accident case 7 illegal operation without license led to a major fire accident the main course of the accident was a major fire in a commercial building in the old city of Luoyang on Christmas Eve in 2000. Taiwan businessmen recently rented the first floor and the first floor of the commercial building to open branches, and planned to open on the 26th. At that time, a dance hall on the fourth floor of the commercial building was holding a Christmas party. Just when the atmosphere of joy was strong, a few clusters of small welding sparks downstairs set the basement under decoration on fire. The fire and smoke spread directly down the stairs to the top floor of the song and dance hall, causing a catastrophic disaster and killing 309 people< (1) the direct cause of the fire was that several welders did not receive professional safety technical training and worked without special work permit< (2) no preventive measures were taken, which resulted in the splashing of red welding slag and ignited the wooden furniture, sofa and other flammable materials in the furniture market on the second floor underground (3) in a panic situation, it is not possible to use a water hose to water down for self-help. Several people left the scene in a panic without calling the police, which delayed the best time to put out the fire and evacuate people, and finally led to a tragic accident What are the main preventive measures< (1) welders must work with certificates and pay attention to fire prevention during welding< (2) proper protective measures should be taken in welding site< (3) special person should be arranged to monitor the fire< (4) inflammables should be 10 meters away from the workplace (5) has a certain number of fire extinguishing equipment, such as sand box, foam extinguisher, etc. Br / >
(6) alarm immediately after the accident to minimize the fire loss< (7) to strengthen the professional ethics education of employees accident case 8 the electric welding operation in the spray booth caught fire the main process of the accident – when the electric welder a was welding a workpiece in the spray booth, the welding spark splashed to the board with thick paint film nearby and caught fire. The workers on the scene were all in a panic. They used brooms and compressed air machines to blow the fire, which eventually led to the expansion of the fire. After half an hour of rescue by the fire brigade, the fire was finally put out, although no one was injured, but caused serious damage to property< The main causes of the accident are as follows: (1) the hot work is carried out without the approval of hot work before welding in the no fire zone, which violates the operation regulations< (2) carry out hot work without removing the paint film and taking any fire prevention measures (3) improper fire-fighting methods and wrong use of compressed air to blow the fire not only extinguished the fire, but also promoted the fire, resulting in the expansion of the accident accident prevention measures – (1) open fire operation is not allowed in the spray booth. 1f welding is necessary, the hot work approval system shall be implemented< (2) clear all combustibles (3) paint room shall have sand, foam or carbon dioxide fire extinguishing equipment. accident case 9 the desorbing tank was used as the grounding electrode of the welding machine, resulting in the accident the accident process – the welder of a factory chose the newly installed desorbing tank as the grounding electrode (there were more than two tons of activated carbon in the tank). During the welding, the activated carbon in the tank was ignited due to the local heating at the wire connection, and the more than two tons of activated carbon were burnt out the main causes of the accident are resistance heat generated by welding current and local heating of activated carbon by electric spark during arc striking how to prevent it correctly it is strictly forbidden to use metal objects as conductors of welding circuit accident case 10 oxygen was wrongly used to replace compressed air, resulting in explosion the main process of the accident – in a hardware store, a welder was repairing the compressor and condenser in the lobby. During the final air pressure test, the welder could not compress the air, so he replaced it with oxygen. When the test pressure reached 0.98mpa, the compressor leaked, The welder carried out repair welding immediately. At the moment of arc striking, the compressor exploded immediately and the shop was destroyed. The welder was killed on the spot and many people were injured the main cause of the accident – (1) the shop can not be used as a welding site (2) all hole covers should be opened before repair welding, and repair welding must be carried out without pressure (3) oxygen is a combustion supporting material and can not replace compressed air< (1) the shop should not be used as a welding site. 1f welding is in urgent need, practical protective measures should be taken, that is, there are no inflammables within 10 meters of the fire point and corresponding fire-fighting equipment< (2) during repair welding, the pressure should be relieved (3) it is strictly forbidden to use oxygen instead of compressed air as test gas accident case 11 explosion of welding repair acid tank main process of the accident – a unit

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