Welding, Cutting and Brazing 29 CFR 1910, Subpart Q I. Background for the Trainer: Any and all applicable standards under subpart Q must be followed for welding operations. II. Speaker’s Notes: This session will cover safety requirements related to welding, cutting, and brazing.

Compressed Gases Covered in Subpart H, but an integral part of welding, cutting, and brazing Compressed gas hazards Gases used for cutting, brazing, and “shielding” the weld I. Speaker’s Notes: Many welding operations will use compressed gases, and therefore, companies must comply with these requirements. The gases are used for cutting, welding, brazing, and “shielding” the weld, which will be discussed later in this session. Compressed gas hazards include compressed energy, flammability, asphyxiation, and oxidation.

Cylinder Inspection Most compressed gas cylinders must be periodically tested/ recertified (DOT) All cylinders contain markings/ symbols that indicate certification status I. Background for the Trainer: Show attendees an actual cylinder if one is available. Point out the certification markings. II. Speaker’s Notes: Only DOT-approved cylinders may be used for welding. Most welding supply houses carry only approved cylinders. According to DOT, these cylinders must be periodically tested and recertified. You can find the last date of certification by looking for the markings on the cylinder.

Specific Gases Several of the gases have specific OSHA standards These gases include acetylene, hydrogen, oxygen, nitrous oxide, ammonia, and LPG I. Speaker’s Notes: Fire and explosion are not the only hazards associated with these gases. Some gases can cause adverse health effects. Gases that are very hazardous are covered under separate OSHA standards. Examples of these gases are listed on the slide.

Basic Fire Prevention Fire hazards must be removed, or Guards installed, or Welding/cutting must NOT take place Hot work permit should be used to ensure that all fire hazards are controlled Use of fire watch 1/2 hour after operation ceases I. Speaker’s Notes: Inspection of the welding area should be conducted to avoid possible fires. It is best to perform welding in a designated area when possible to avoid additional hazards. If the fire hazard cannot be removed, guards will be installed or the welding/cutting must not take place. Be sure to obtain a hot work permit before performing any welding jobs. This will help ensure that all hazards are controlled. Someone must also be posted as a fire watch from the time welding begins to one-half hour after the job is done.

Fire Prevention (cont.) Fire extinguishers must be charged/available Never weld in the presence of explosive atmospheres Do not weld on used drums, barrels, tanks, or other containers Test potentially explosive containers for flammable atmospheres Shut off cylinder valves when they are not in use I. Speaker’s Notes: This slide describes additional fire prevention techniques associated with welding. Make sure that anyone who uses a fire extinguisher has been properly trained. It may be necessary to inert drums or fill them with water to eliminate flammable/explosive vapors prior to welding or cutting.

Protection of Personnel Keep working surfaces clean and unobstructed Wear eye protection Use safety glasses under welding hood Protective clothing must be used per 1910.132 Welding in confined spaces Machines located outside of space Other confined space precautions apply (1910.146) I. Background for the Trainer: Show any available PPE for use while welding (i.e., helmets, gloves, aprons, etc.). II. Speaker’s Notes: Face and eye protection is imperative to avoid possible welder’s flash, which can permanently damage your eyesight. Any welding in a confined space must be monitored to quantify the hazard to the welder and any other space entrants.

Oxygen-Fuel Welding 29 CFR 1910.253 Acetylene Flammable Unstable Cannot be piped above 15 psi I. Speaker’s Notes: Acetylene is extremely dangerous because of its flammability range. Oxyacetylene torch cutting is very common throughout the industry as it has a wide flammable range. Acetylene is extremely unstable. Acetylene is generated in the cylinder from a reaction of acetone and calcium silicate. Acetylene must not be piped above 15 psi.

Basic Rules for Oxyacetylene Welding Blow out cylinder valve Release regulator Stand to one side of regulator Open cylinder valve slowly Not more than 15 psi I. Speaker’s Notes: This slide lists basic rules to follow when welding with oxyacetylene. Before connecting to the regulator, always blow out the cylinder valve. Release the regulator by adjusting the screw before opening the cylinder valve. Always stand to the side of the regulator while opening the cylinder in case of accidental pressure release. Open the valve cautiously and slowly. Never use acetylene at pressures above 15 pounds per square inch.

Basic Rules (cont.) Purge oxygen and acetylene passages Light the acetylene Never use oil or grease Do not use oxygen Keep your work area clean I. Speaker’s Notes: Before lighting the torch, remember to purge acetylene and oxygen passages. Before opening the oxygen on the torch, light the acetylene. Never use oil or grease on regulators, tips, or any part that may come into contact with oxygen. Do not use oxygen as a substitute for air. Always keep your work area free of items that could ignite.

Storage of Fuel Cylinders Storage area must be well ventilated Cylinders must be at least 20 feet from combustibles Valves must be closed Valve protection must be in place Inside storage must be limited to 2,000 cubic feet. Cylinders must be stored in upright position Oxygen must be at least 20 feet from fuel gas or 5 feet with a 1/2 hour fire barrier I. Speaker’s Notes: Valve protection caps are designed to take a blow should the cylinder fall, thus preventing the cylinder from impersonating a rocket. Never lay the cylinder down; store it upright and always secure it during storage. Regulators should be only on cylinders in use, not on those that are stored.

Gas Cylinder Precautions Never lift cylinders by the service valve or valve protection (use slings, net, etc.) Keys, handles, hand wheels must be present Use proper regulator Open acetylene valve no more than 11/2 turns I. Speaker’s Notes: Handling cylinders properly is important because of the extreme pressure they are under. Use these precautions at all times.

Protective Devices Pressure relief valves Backflow preventers Fuel gas hose—red (sometimes black) Oxygen hose—green Hose protection required Pressure-reducing regulators I. Background for the Trainer: Show any valves, backflow preventers, and hoses you may have. II. Speaker’s Notes: These types of safety devices are important to prevent potential fires and/or explosions. Make sure the system that has been approved remains intact and that high-pressure regulators, etc., are not substituted for approved regulators.

Arc Welding Electric current fuses parent metal and welding rod Indispensable in metal working Used for carbon and alloy steels and non-ferrous metals I. Speaker’s Notes: Arc welding is very common. A high percentage of industrial welding is arc or “stick” welding.

Shielding Air must be kept away from weld area Shielding protects the integrity of the weld joint Flux or gas mixture is used as a “shield” I. Speaker’s Notes: Shielding gases help create a more perfect weld and protect the weld area during the process. When contaminants enter the weld area, they can create defects, and shielded welding helps prevent this.

Common Arc Welding Processes Shielded metal arc welding (stick welding) Gas metal arc welding (MIG welding) Gas tungsten arc welding (TIG welding) Flux cored arc welding Submerged arc welding Arc cutting Plasma arc cutting I. Speaker’s Notes: These are the various types of arc welding. Arc welding such as TIG and MIG use a shielding gas.

Installation and Maintenance Welding machine must be grounded Work area must be dry and free of hazards Connections must be tightly made Splices within 10 feet of holder are prohibited Cables must be maintained and conductors well insulated I. Speaker’s Notes: Follow these straightforward rules for maintaining safe welding equipment.

Welding Health Hazards Zinc Cadmium Beryllium Iron Oxide Mercury Lead Fluorides Chlorinated hydrocarbon solvents Phosgene Carbon monoxide Ozone Nitrogen Oxides I. Speaker’s Notes: These materials can be liberated during the welding process. Welding operations should be monitored to see what concentration of these contaminants may be reaching the welder’s breathing zone. An industrial hygienist should be familiar with the appropriate monitoring techniques for welding fume. 11006115 Copyright ã1999 Business & Legal Reports, Inc.

Welding Physical Hazards Ultraviolet radiation Infrared radiation Intense visible light I. Speaker’s Notes: These hazards are usually handled with eye and face protection as well as welder’s clothing such as aprons and chaps. Eye and face protection must have certain shades to prevent exposure to welding radiation.

Lens Shades for Typical Welding Welding Process Shielded metal arc Gas metal arc Gas Tungsten arc Torch brazing Gas welding Lens Shade Number 10-14 11-12 12 3 or 4 4-8 I. Background for the Trainer: Show any welding helmets, glasses, or goggles that may be available. II. Speaker’s Notes: Because the shades vary for the different types of welding, it is important that routine inspections be conducted to ensure that the proper shades are used on the various welding operations.

Quiz 1. Fuel cylinders must be stored at least _____ feet from combustibles. 2. Shielding is a process used to protect the eyes from welding fume. True or False 3. Three physical welding hazards are ____________ radiation, infrared radiation and intense visible light. 4. You should not use oxygen as a substitute for air. True or False 5. As long as they are secure, fuel cylinders can be stored on their side. True or False I. Background for the Trainer: Hand out the quiz copies. Go over the questions verbally and have the employees write their answers on their quiz sheets.

Quiz (cont.) 6. Gas Metal Arc Welding is also known as _____________ welding. 7. Exposure to zinc fumes may cause metal fume fever. True or False 8. Cylinder inspection requirements are regulated by the Department of ____________________. 9. Acetylene has a very narrow flammable range. True or False 10. Backflow prevention should be provided for oxygen cylinders. True or False

Quiz Answers 1. Fuel cylinders must be stored at least 20 feet from combustibles. 2. False. Shielding is a process used to keep air away from the weld. 3. Three physical welding hazards are ultraviolet radiation, infrared radiation, and intense visible light. 4. True. You should not use oxygen as a substitute for air. 5. False. Fuel cylinders must always be stored upright. 6. Gas Metal Arc Welding is also known as MIG welding.

Quiz Answers (cont.) 7. True. Exposure to zinc fumes may cause metal fume fever. 8. Cylinder inspection requirements are regulated by the Department of Transportation. 9. False. Acetylene has a very wide flammable range. 10. True. Backflow prevention should be provided for all oxygen cylinders.