welding cutting brazing safety

8/6/2019 Welding Cutting Brazing Safety

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BLR¶sSafety Training Presentations

Welding, Cutting and Brazing29 CFR 1910, Subpart Q




Covered in Subpart H, but an integral part of welding, cutting, and brazing

Compressed gas hazards

Gases used for cutting, brazing,and ³shielding´ the weld

Compressed Gases




Most compressed gas cylindersmust be periodically tested/recertified (DOT)

All cylinders contain markings/symbols that indicate certificationstatus

Cylinder Inspection




Several of the gases have specificOSHA standards

These gases include acetylene, hydrogen,oxygen, nitrous oxide, ammonia, and LPG

Specific Gases




Basic Fire Prevention

Fire hazards must be removed, or

± Guards installed, or

± Welding/cutting must NOT take place

Hot work permit should be used toensure that all fire hazards are controlled

Use of fire watch

± 1/2 hour after operation ceases




Fire extinguishers must becharged/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 flammableatmospheres

Shut off cylinder valveswhen they are not in use

Fire Prevention (cont.)




Protection of Personnel

K eep 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)




29 CFR 1910.253

Acetylene

± Flammable

± Unstable

± Cannot be piped above 15 psi

Oxygen-Fuel Welding




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




Basic Rules (cont.)

Purge oxygen and acetylene passages

Light the acetylene

Never use oil or grease

Do not use oxygen

K eep your work area clean




Storage area must be well ventilated

Cylinders must be at least 20 feet fromcombustibles

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

Storage of Fuel Cylinders




Never lift cylinders by the service valve or valve protection (use slings, net, etc.)

K eys, handles, hand wheels must be present

Use proper regulator

Open acetylene valve no more than 11/2 turns

Gas Cylinder Precautions




Protective Devices

Pressure relief valves

Backflow preventers

Fuel gas hose²red (sometimes black)

Oxygen hose²green

Hose protection required

Pressure-reducing regulators




Arc Welding

Electric current fuses parent metal andwelding rod

Indispensable inmetal working

Used for carbon andalloy steels and non-ferrous metals




Air must be kept away from weld area

Shielding protects the integrity of theweld joint

Flux or gas mixture is used as a ³shield´

Shielding




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




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 conductorswell insulated

Installation and Maintenance



Welding Health Hazards

Zinc Cadmium Beryllium

Iron Oxide Mercury Lead Fluorides

Chlorinatedhydrocarbon solvents

Phosgene Carbon monoxide Ozone

Nitrogen Oxides





Welding Physical Hazards

Ultraviolet radiation

Infrared radiation

Intense visible light




Lens Shadesfor Typical Welding

WeldingProcess

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




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 False3. Three physical welding hazards are ____________

radiation, infrared radiation and intense visible light.

4. You should not use oxygen as asubstitute for air. True or False

5. As long as they are secure, fuelcylinders can be stored on their side. True or False




Quiz (cont.)

6. Gas Metal Arc Welding is alsoknown as _____________ welding.

7. Exposure to zinc fumes may cause

metal fume fever. True or False8. 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 fromcombustibles.

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 metalfume 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.

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