Safety during welding: the place of welding, personal protective equipment

Welding is a process for obtaining reliable joints between parts. It is always accompanied by increased risks to human health. In this regard, safety precautions during welding should be observed.

General concept of labor protection

In order for security measures to be fully implemented, a management system exists. Labor protection during welding provides for a comprehensive mechanism for regulating compliance with safety rules during specific technological operations. There is a list of legal acts at the level of the state, region, industry, enterprise, workshop.

1. GOSTs, regulating the features of technologies and their control.
2. Technological and management documentation.
3. Safety rules, labor protection, in-house and specialized instructions.
4. Legal mechanisms to hold accountable for non-compliance with safeguards.

Legal acts stipulate the activities of special services designed to monitor whether safety precautions are observed during welding, to provide necessary equipment, to conduct regular training and to hold accountable for non-compliance with safety measures.

Rules for preparing for welding

The initial stage should be accompanied by a check:

1. Knowledge and briefing on the topic: "Safety during welding."
2. The workplace, ensuring its cleanliness, the absence of excess objects and flammable substances.
3. The integrity and serviceability of personal protective equipment, ventilation; power sources, cables, couplings, grounding, insulation (arc welding); acetylene generators, gas cylinders, gearboxes, pressure gauges, burners (gas welding).
4. Mutual compliance of equipment in terms of maximum permissible voltage, current, gas pressure.
5. The floor covering is subject to moisture and the presence of a rubber mat.
6. The availability of fire extinguishing media.

Design of a post for arc welding

Occupational health and safety regulations regulate the appropriate equipment of the workplace:

1. Ensuring high-quality lighting and ventilation, in the absence of well-established ventilation, an artificial ventilation system should be created.
2. Coating walls and floors with refractory paints or special plaster should have a high degree of UV repulsion.
3. Grounding of power sources: transformers, rectifiers, oscillators, etc.
4. Careful isolation of all connections, the use of high-quality couplings.
5. Availability of automatic voltage interruption systems in case of breaks and malfunctions.
6. The diameter of the cable should correspond to the current strength: 10 mm² - 100 A, 25 mm² - 200 A, 35 mm² - 300 A, 70 mm² - 500 A.
7. The correct selection of electrodes. The cable is connected to the voltage source and to the electrode holder using couplings and terminals. Twisting and other methods of improvised fastenings are not allowed.
8. The presence of rubber mats, special protective clothing and shoes of the welder, gloves, a mask with a light filter.
9. Supply with fire extinguisher and access to cold water.

The technical assurance of compliance with the safety of the production process should be documented in appropriate plans and maps.In the absence of a special cabin or post, all of the above precautions are followed without fail.

Arc welding

Welding with an electric arc must be accompanied by the following rules:

1. Checking product cleanliness, quality of stripping and edge processing.
2. In the case of welding structures previously in contact with petroleum products or other flammable substances, check the quality of the additional cleaning steps.
3. Clearly comply with the standards, observe the maximum permissible voltage and current values.
4. Use low voltage lighting (up to 12 V).
5. Lack of direct contact with electrode holders and terminals.
6. In situations where work is carried out in a free territory without a specially equipped post, perform actions under a covering that protects from the weather, with the mandatory observance of the characteristics of metal weldability.
7. In the welding workshop, the distance between the transformers is at least 1 m.
8. Carry out high-altitude welding using scaffolding.

Breaks or cessation of actions are observed by a complete shutdown of the entire system and associated equipment.

Completion of electric arc welding

The end of the workflow is accompanied by:

1. Disconnecting power sources.
2. Disconnecting all terminals.
3. By checking the serviceability of all the main and auxiliary elements, as well as the absence of possible sources of ignition, in the presence of smoldering sparks, carefully extinguish them.
4. Packing and sorting equipment and protective clothing.
5. Cleaning the workplace.
6. Thoroughly ventilate the room.
7. Personal hygiene.
8. Informing the authorities about all violations or malfunctions.

Design post for gas welding

The place of welding should be characterized by the following requirements:

1. The presence of the necessary lighting and ventilation.
2. Acetylene generators are installed on a metal pallet, at a distance of 10 m from the place of welding. The volume of air in the room to permit their use is 60 m³. They must be charged with calcium carbide and water in strict accordance with regulatory requirements, installed vertically with an accompanying purge of the remaining air. It is mandatory to check the operability of the water lock, filling it with water or a non-freezing liquid.
3. Gas cylinders are marked accordingly (acetylene - red, oxygen - blue). Installed vertically at a distance of more than 5 m from the workplace. They are transported to the post using special equipment, without blows, separately from each other. It is forbidden to carry on shoulders or in hands!
4. Serviceability of gearboxes, pressure gauges, hoses and burners.
5. Persons who participate in (as the rules establish) welding should have special clothing, shoes, protective gloves, masks with light filters, as well as free access to cold water.
6. The absence at the post and near flammable substances and objects, a source of fire or a spark.

Gas welding

Occupational health and safety conditions stipulate gas welding with maximum professionalism and caution, in compliance with all rules and regulations.

1. Checking the quality of preparation of welded products and their edges, the absence of oily and flammable substances on their surface.
2. In case of overcooling of the generator and cylinders, they should be heated exclusively with steam or rags moistened with warm water.
3. Establishing connections between burners, hoses, gearboxes on cylinders, checking fastenings and equipment compliance with each other. The color of gas hoses and gearboxes: red for acetylene, blue for oxygen. In the case of using an acetylene generator, injection burners are used, where acetylene is supplied at a pressure of 0.02 MPa and oxygen is 0.2-0.3 MPa.If the cylinder is used, non-injector burners, where the acetylene feed pressure is 0.1 MPa.
4. Selection of the tip for the burner and filler wire, depending on the thickness of the welded part: 0.5-1.0 mm - No. 0, 2-4 mm - No. 2, 6-9 mm - No. 4, etc.
5. Precise pressure control at the inlet to the gearbox and at the outlet. The maximum allowable strength of gas hoses: 2 MPa, acetylene - 0.63 MPa.
6. Check for sufficient water in the water lock.
7. Start the burner by opening the oxygen valve, then the acetylene valve. The completion of the work is accompanied by actions in the reverse order. In the event of a return shock, urgently close the acetylene, and then the oxygen valve.
8. It is forbidden to carry out operations using dubious or faulty equipment.
9. Do not touch valves on cylinders or gearboxes with gloves containing particles of oil or other flammable substances!

Requirements for welding work are documented in writing, voiced in regular briefings and monitored by inspectors and safety engineers.

Gas welding completion

Safety during welding requires compliance with the rules for the completion of welding in accordance with a clear regulation:

1. Stop gas supply through the burner: shut off the acetylene, and then the oxygen valve.
2. Overlapping cylinders, deactivating the generator, cleaning in accordance with the requirements, including transportation.
3. Distribution of all main and auxiliary equipment in places.
4. Cleaning, thorough ventilation.
5. Elimination of possible sources of ignition.
6. Report to superiors about unusual situations, risks, problems.

Critical Safety Rules

1. Urgent suspension of welding and informing superiors.
2. If a fire occurs, immediately remove cylinders, generators, current sources and other high-risk equipment to a safe distance; start to deactivate ignitions using carbon dioxide fire extinguishers, asbestos material, sand, water, in case of a high degree of danger, call an additional inspection service and fire fighting service.
3. In the event of a back-strike, an urgent shut-off of the gas supply to the burner, reducers. To reduce the risk of danger - check the water lock and add water.
4. In a situation of critical gas contamination - stopping the work process and thoroughly ventilating the room.
5. Interruption of welding in situations unsuitable for its implementation: equipment malfunction, negative weather conditions when working in the open air, instability or unpreparedness of parts to be welded. Informing the labor protection service and management.
6. Primary care in case of burns and other injuries. In a situation of danger to vision, rinse eyes and consult medical staff.
7. Report all situations to management, in extremely critical circumstances, do not change the position of objects in order to simplify further investigation.

Due to the fact that this type of technological operations is accompanied by an increased risk to human life and health, safety procedures during welding should be ensured, documented, subject to regular system checks and increased informational content of personnel, strictly observed and performed by all employees.