Presentation on theme: "Welding, Cutting, And Brazing"— Presentation transcript:
1 Welding, Cutting, And Brazing Slide Show NotesWelcome to the training session about welding, cutting, and brazing safety.The applicable OSHA regulations are located at 29 CFR to 255 (Subpart Q)
2 Session Objectives You will be able to: Identify major safety and health hazards of weldingSelect appropriate PPE for welding, cutting, and brazingImplement controls to prevent or control firesSlide Show NotesBy the end of the training session, you will be able to:Identify major safety and health hazards of weldingSelect appropriate PPE for welding, cutting, and brazingImplement controls to prevent or control fires
3 Types of Welding Welding includes 60 or more process variations Electric welding and oxy-fuel gas weldingWelding/cutting occurs at most businesses at some pointSlide Show NotesWelding is a general term that describes 60 or more processes that use heat to fuse metals together.The processes include electric “arc” welding as well as oxygen or “oxy” – fuel gas cutting or welding.Cutting or welding occurs at most business at one time or another as part of construction, maintenance, or repairs. Welding is part of the core business for some industries such as metal fabrication.Discuss the types of welding done at your facility.Modify this slide to describe the specific types of welding at your facility.
4 Welding Hazards Fires—caused by unsafe welding or cutting operations BurnsElectric ShockLight radiation— ultraviolet, infrared, and intense visible lightAir Contaminants (gases, fumes, smoke)Slide Show NotesAbout 6% of industrial fires causing loss of human life are due to unsafe welding or cutting operations. Such fires start when sparks from small pieces of molten metal or slag (larger pieces of molten metal) come in contact with flammable or combustible materials.Burns to the body.Electric shock and burns from electric (arc) welding.Radiation: ultraviolet causes flash burns; infrared causes heat burns, irritation; intense visible light causes headache and eye strain.Air Contaminants: Combustion gases, material – metallic oxides, mineral dusts, toxic fumes.Ask the participants to discuss specific incidents that have happened at your facility or in your industry.
5 Basic Fire Prevention Inspect welding area before starting Remove fire hazardsInstall guardsWelding or cutting must NOT take place unless hazards removed or guards installedObtain a hot work permit before starting operations to ensure that all fire hazards are controlledPost a fire watch person 1/2 hour after operation ceasesSlide Show NotesInspect the welding area before operations begin to eliminate possible fire sources.It is best to perform welding in a designated area when possible to avoid additional hazards, otherwise remove fire exposures from the immediate area if possible.If the fire hazard cannot be removed, guards must be installedIf fire hazards are not removed, or guards are not installed, the welding or cutting operation 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 at least 1/2 hour after the job is done.
6 Fire Prevention (cont.) Never weld in explosive atmospheresDo not weld on used containersTest potentially explosive containers for flammable atmospheresShut off cylinder valves when not in useSlide Show NotesHere are fire prevention techniques associated with welding.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. It may be necessary to use special techniques such as inerting the space inside a container to eliminate flammable/explosive vapors prior to welding or cutting.
7 VentilationThree factors govern the amount of contamination to which welders may be exposed:Dimensions of the spaceNumber of weldersPossible evolution of hazardous fumesManagement must ensure welders have proper protection and ventilationSlide Show NotesThree factors govern the amount of contamination to which welders may be exposed:Dimensions of the spaceNumber of weldersPossible evolution of hazardous fumesManagement is responsible for ensuring welders have proper protection and ventilation
8 Oxygen-Fuel Gas Welding AcetyleneFlammableUnstableCannot be used above 15 psiOxygenAdded to support fuel gas flame and obtain high temperature for melting steel (welding)Slide Show NotesThe primary fuel gases for welding, cutting, and brazing operations are:Acetylene, which is flammable, unstable, and cannot be used above 15 pounds per square inch (psi).OxygenAdded to support fuel gas flame and obtain high temperature for melting steel (welding).
9 Basic Rules for Oxy-acetylene Welding Ensure the safety fuse plug or disk is functionalAttach regulatorStand to one side of regulatorOpen cylinder valve slowlyNot more than 15 psiSlide Show NotesO2 and Acetylene have different fittings and hose colors so they cannot be misconnected. Here are the basic rules to follow when working with Oxy-acetylene gas-fueled systems:Compressed gas cylinders must have a safety fuse plug or disk; check it to make sure it is functioning.Never use oxygen or fuel gases directly from the cylinder; there must be a regulator attached to the valve.Stand to one side of regulator to avoid injury if it malfunctions.Open the cylinder valve slowly.Use 3-7 psi for O2, and 1-12 psi for acetylene, but never over 15 psi.
10 Basic Rules for Oxy-acetylene Welding (cont.) Purge oxygen and acetylene linesLight the acetyleneNever use oil or grease near oxygenDo not use oxygen to clean or blow off dirt or clothingKeep your work area cleanSlide Show NotesPurge oxygen and acetylene linesLight the acetyleneDon’t mix oxygen with grease or oilMixture can cause spontaneous combustion and fire. Remember that oxygen and most other gases are stored under high pressure (2200 psi).Do not use oxygen to clean or blow off dirt or clothing because it dramatically increases the combustibility of the materialKeep work area clean so as not to introduce unnecessary fire hazards
11 Store Gas Cylinders Safely The storage area must be well ventilatedKeep fuel cylinders 20 feet or more from combustiblesClose valves, ensure valves are protectedLimit inside storage to 2,000 cubic feetStore cylinders in the upright position and secured from fallingSeparate oxygen from fuel gasSlide Show NotesStorage area must be well ventilatedFuel cylinders must be at least 20 feet from combustiblesValves must be closed. Regulators should only be on cylinders in use, not on those that are stored. Valve protection must be in place. Valve protection caps are designed to take a blow should the cylinder fall, thus preventing the cylinder from impersonating a rocket.Inside storage must be limited to 2,000 cubic feetCylinders must be stored in upright position and secured from falling. Never lay the cylinder down; store it upright, and always secure it during storageOxygen storage. Keep fuel gas and oxygen separated by at least 20 feet, or keep separated by a 5-foot-high barrier with at least a half-hour fire rating.
12 Follow Gas Cylinder Precautions Never lift cylinders by the service valve or valve protection (use slings, net, or other approved means)Keys, handles, and hand wheels must be presentUse the proper regulatorOpen acetylene valve no more than 11/2 turnsIf in doubt about a cylinder, don’t use itSlide Show NotesHandling cylinders properly is important because of the extreme pressure contained in each cylinder. Use these precautions at all times.Never lift cylinders by the service valve or valve protection (use slings, net, or other approved means).Keys, handles, and hand wheels must be present.Use the proper regulator.Open acetylene valve no more than 11/2 turns.If you are uncomfortable with the way a cylinder looks, don’t use it.
13 Use Protective Devices Pressure relief valves, backflow preventers or check valvesFlash back arrestorsFuel gas hose—red (sometimes black)Oxygen hose—greenHose protection requiredPressure-reducing regulatorsSlide Show NotesMake sure that a system that has been approved for use remains intact, and that approved regulators have not been substituted with other regulators such as high-pressure regulators. The following types of safety devices are important to prevent potential fires and/or explosions:Pressure relief valves, and backflow preventers or check valvesFlash back arrestorsFuel gas hose—red (sometimes black)Oxygen hose—greenHose protection requiredPressure-reducing regulators
14 Protect Yourself Keep working surfaces clean and clear Light torches with a striker, not a lighter!Wear face and eye protectionUse safety glasses under welding hood and burning goggles with proper shadingWear protective body clothingAvoid synthetic clothingUse leather gloves with gauntletSlide Show NotesKeep working surfaces clean and unobstructed.Light torches with a striker. Do not use butane lighters. Welders have been killed by slag or sparks hitting a lighter in their pocket and causing an explosion.Wear eye protectionUse safety glasses under welding hood and burning goggles with proper shading to protect against ultraviolet and infrared exposure. Face and eye protection is imperative to avoid possible welder’s flash, which can permanently damage your eyesight.Protective clothing must be worn during welding, cutting, and brazing operations.Avoid synthetic clothing – synthetic clothing melts readily. Wear cotton or wool.Wear leather gloves w/gauntlet.Show samples of personal protective equipment for use while welding (i.e., helmets, gloves, aprons, etc.).
15 Lens Shades Generally, use a 4–5 shade for: Torch brazing Oxy-fuel gas cutting/weldingSlide Show NotesBecause 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. Check the manufacturer or OSHA charts for specific welding applications.Generally a 4 – 5 shade is used for:Torch brazingOxy-fuel gas cutting/weldingShow welding helmets, glasses, or goggles.
16 Oxy-Acetylene Welding—Any Questions? Any questions about oxy-acetylene welding safety?Slide Show NotesAre there any questions about the safety specifications or safe work practices for oxy-acetylene welding?
17 Arc Welding—Common Processes Shielded metal arc welding (stick welding)Gas metal arc welding (MIG welding)Gas tungsten arc welding (TIG welding)Flux cored arc weldingSubmerged arc weldingArc cuttingPlasma arc cuttingSlide Show NotesThe following are the various types of arc welding processes.Shielded metal arc welding (stick welding)Gas metal arc welding (MIG welding)Gas tungsten arc welding (TIG welding). Arc welding such as TIG and MIG use a shielding gas.Flux cored arc weldingSubmerged arc weldingArc cuttingPlasma arc cuttingModify this slide to describe the arc welding process(es) at your facility.
18 Arc Welding Hazards and Safety Measures Arc gives off ultraviolet and infrared rays the same as those causing sunburnExposure within several inches to a few feet can cause flash burn to eyes and skinSafety measuresAvoid wet or damp areas—promotes electric shock hazardAvoid oil, grease, and flammables as they pose a fire hazardSlide Show NotesArc welding is very common. A high percentage of industrial welding is arc or “stick” welding. Electric current fuses parent metal and welding rod. The typical electrical current = amps at up to 80 volts. Arc welding is indispensable in metal working. It is used for carbon and alloy steels and nonferrous metals.The safety hazards of arc welding are:Arc gives off ultraviolet and infrared rays the same as those causing sunburnExposure within several inches to a few feet can cause flash burn to eyes and skinSafety measures for avoiding hazards of arc welding include:Avoid wet or damp areas – promotes electric shock hazardAvoid oil, grease and flammables as they pose a fire hazard
19 Shielding and Flash Screens Air must be kept away from weld areaShielding protects the integrity of the weld jointFlux or gas mixture is used as a “shield”Welders need to erect flash screens around them to protect others in areaSlide Show NotesAir must be kept away from the weld area so as not to introduce contaminants.Shielding protects the integrity of the weld joint.Shielded gas welding uses an inert gas to keep air away from the weld area and protect the integrity of the weld.Using flash screens protects others in the area from the flash associated with welding.
20 Maintain Equipment Properly Welding machines must be groundedWork area must be dry and free of hazardsConnections must be tightly madeCable splices within 10 feet of holder are prohibitedCables must be maintained and conductors well insulatedSlide Show NotesFollow these straightforward rules for the safe maintenance of welding equipment.Welding machines must be groundedWork area must be dry and free of hazardsConnections must be tightly madeCable splices cannot be within 10 feet of holderCables must be maintained and conductors must be well insulated
21 Protect YourselfWear welding helmets with proper shading depending on type of arcDO NOT use brazing gogglesWear safety glasses under helmetWear leather gloves with gauntletsUse ventilation or respiratorsWear leather bibs, sleeves, or jackets to prevent burns from slag, sparks, and ultravioletSlide Show NotesHere are some procedures to follow in order to protect yourselves from injury.Wear welding helmets with proper shading depending on type of arc.DO NOT use brazing goggles.Wear safety glasses under helmet.Wear leather gloves with gauntlets.Use ventilation or respirators.Wear leather bibs, sleeves or jackets to prevent burns from slag, sparks and ultraviolet.
22 Lens Shades Generally, use a 10–14 shade for: Shielded metal arc Gas metal arcGas tungsten arcSlide Show NotesBecause 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. Check the manufacturer or OSHA charts for specific welding applications.Generally a 10 – 14 shade is used for:Shielded metal arc weldingGas metal arc weldingGas tungsten arc weldingShow any welding helmets, glasses, or goggles that may be available.
23 Arc Welding—Any Questions? Any questions about arc welding?Slide Show NotesAre there any questions about the safety specifications or safe work practices for arc welding?
24 Key Points to Remember Major hazards include: FireBurnsShockToxic exposuresFollow proper procedures to prevent firesUse appropriate engineering controlsWear appropriate PPESlide Show NotesAll types of welding processes used today involve high heat and potential for fires, burns and other hazards. Know the hazards in your area. Some of these hazards include:FireBurnsShockToxic exposures to fumes, gases and vapors.Follow proper procedures to prevent fires.Use appropriate engineering controls such as ventilation, shields and screens to protect you or others in the area.Wear appropriate PPE such as gloves, safety glasses, helmets, and aprons.