Welding Osha

8/11/2019 Welding Osha

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Welding, Cutting, and Brazing

MODULE 16


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2 2006 TEEX

Hazards of Welding Operations

Fire hazardsMetal splatter

Electric shockExplosion hazardsReleased gases

Radiant energyWhere would these hazards be foundon oil and gas well sites?


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3 2006 TEEX

Three Basic Types of Welding

Gas Slower and easier to control thanelectric arc. Uses gas flame over metals untilmolten puddle is formed. Most popular fuels

used with oxygen include acetylene, mappgas, and hydrogen.Arc Two metals are joined by generating anelectric arc between a covered metalelectrode and the base metal.Oxygen and Arc Cutting Metal cutting inwelding is the severing or removal of metal bya flame or arc.


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4 2006 TEEX

Oxygen and arc cutting

Most common cutting processes :Oxygen Cutting: Metal is heated by gas

flame and an oxygen jet does the cutting.Arc Cutting: Intense heat of electric arcmelts away the metal.


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General Requirements

29 CFR 1910.252


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7 2006 TEEX

Fire Prevention Safeguards

Fire Hazards should be removed if thewelded object cannot be readily moved.

Guards should be used if removing firehazards is not possible.Restrictions apply (no cutting or

welding allowed) if none of the above ispossible.


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Subtitles & Transitions

FOR EXAMPLE


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9 2006 TEEX

Special Precautions

Protect nearby combustible materials fromsparks that might escape through openings in

floors or walls.Fire Extinguishers must be ready for instantuse.Fire Watch lasting at least 30 min afterwelding or cutting operations is required ifmore than a minor fire might develop and ifcertain combustible materials are present.


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10 2006 TEEX

Special Precautions

Authorization : A responsible individualmust inspect the area and designate

precautions, preferably by writtenpermit.Floors : Combustible materials must be

swept 35 feet away; combustible floorsmust be wetted or protected (whilepreventing arc welding shock)


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11 2006 TEEX

Special Precautions

Prohibited areas for welding:Unauthorized by management

Where sprinklers are impairedExplosive atmospheresNear storage of large quantities of readilyignitable materials

Relocation of Combustibles :Combustibles shall be moved 35 feetaway or properly protected or shielded.


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12 2006 TEEX

Special Precautions

Ducts: Ducts & conveyor systems that mightcarry sparks must be shut down.Combustible walls must be shielded orguarded.Noncombustible walls , partitions or ceilings(when welded) require opposite-side movingof combustibles or a fire watch.Combustible cover: No welding on certainmetal building components havingcombustible covers or layers.


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13 2006 TEEX

Special Precautions

Pipes (or any metal) close enough tocombustibles to cause ignition by

conduction may not be cut or welded.Management responsibilities:

Establish proper areas and procedures

Designate responsible individualEnsure training

Advise contractors of hazards


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14 2006 TEEX

Special Precautions

Supervisor responsibilities:Safety of equipment & procedures

Determine combustibles & hazardous areasProtect combustibles from ignition throughmoving, shielding and schedulingSecure authorizations

Give go-ahead to cutter or welderEnsure fire protectionEnsure fire watches if required


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15 2006 TEEX

Welding or Cutting Containers

Used containers must be cleaned offlammable materials or other materials

that could release toxic of flammablevapors when heated.Venting & purging is required for

hollow spaces or cavities.


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16 2006 TEEX

Confined Spaces

Precautions must be taken during long*pauses in arc welding to prevent

accidental contact of electrodestorch valve gas leaks in gas welding.

*During lunch or overnight


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17 2006 TEEX

Protection of Personnel

Railing or other suitable fall protectionmust be provided as required.

Welding cable and other equipmentmust be kept clear of passageways,ladders and stairways.Eye protection and protectiveequipment of specific appropriate typesmust be worn. Nearby workers must beprotected from arc welding rays.


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Subtitles & Transitions

FOR EXAMPLE


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19 2006 TEEX

Protection of Personnel

Work in confined spaces requiresconsideration of:

VentilationSecuring cylinders and machineryLifelinesElectrode removal (arc welding)Gas cylinder shutoff (gas welding &cutting)Warning signs for hot metal


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20 2006 TEEX

Health Protection & Ventilation

General requirements for protectingwelders are based on 3 factors:

Dimensions of space (especially ceilingheight) in which welding is to be doneNumber of welders

Possible evolution of hazardous fumes,gases, or dust according to the metalsinvolved.


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21 2006 TEEX

Natural and MechanicalVentilation

Must not be restricted by screensSufficient to keep concentrations


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22 2006 TEEX

Dilution Ventilation

Contaminantshould travelaway frombreathing zone.Local exhaustventilation maybe moreeffective.

Poor Fair

Good Best


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23 2006 TEEX

Ventilation

Confined space: ventilation first;respirators if ventilation impossible

Specific rules for specific chemicalsOutdoors: Just stay below PEL


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24 2006 TEEX

Transmission pipeline

Special rules in 1910.252(d)(1)Special electric shock protection for wetconditionsPressure testing: Worker and publicprotection against blowing out or loose dirtConstruction: API Std. 1104-1968

Flammable substance lines: API Std. PSDNo. 2201-1963X-ray inspection: ANSI Z54.1-1963


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25 2006 TEEX

Oxygen-Fuel GasWelding & Cutting

General RequirementsFlammable mixtures of fuel gases and air

or oxygen must be guarded against.Maximum pressures of 15 psi foracetylene must be observed (with certainrare exceptions).

Approved apparatus.Competent personnel in charge of supplyequipment


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26 2006 TEEX

Cylinders & Containers

Approval & Marking:DOT compliantLegibly marked

ANSI compliant connectionsValve protection


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27 2006 TEEX

Cylinders & Containers: Storage

Away from heat sources (such as radiators)When inside buildings:

Well-protected, ventilated, dry location at least 20ft from combustibles Assigned storage spaces, protected from damage& tampering

When empty: closed valvesWhen not in use: hand-tight valve protectioncaps


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28 2006 TEEX

Oxygen Storage

Protect oxygen cylinders from fire hazards such as acetylene:

Distance: 20 ft from fuel-gas cylinders or combustibles, orBarrier: 5 ft high noncombustible partition with half-hour fire-resistance rating


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29 2006 TEEX

Arc Welding & Cutting

Use compliant equipmentSpecial design for exposure to weather,

flammable gases, marine conditions Workmen who operate or maintain arcwelding equipment shall be acquainted

with the requirements of 1910.254 and1910.252


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30 2006 TEEX

Arc Welding & Cutting

Electrode holders when not in use must bekept from shocking people and objects.Protect against electric shock:

Never use cables with splices within 10 feet (3 m)of the holderThe welder should not coil or loop weldingelectrode cable around parts of his body

Maintenance must ensure safety:Damaged cables & equipment must be replaced.Work and cables must be joined properly andhave adequate insulation.


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31 2006 TEEX

Operating procedures

Cylinders, cylinder valves, couplings,regulators, hose, and apparatus kept

free from oily or greasy substancesOxygen cylinders shall not be handledwith oily hands or gloves

A jet of oxygen must never be permittedto strike an oily surface, greasy clothes,or enter a fuel oil or other storage tank


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37 2006 TEEX


Before connecting a regulator to acylinder valve:

Open the valve slightly; close immediatelyOpen the valve while standing to oneside of the outlet; never in front of itNever crack a fuel-gas cylinder valvenear other welding work or near sparks,flame, or other possible sources ofignition


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38 2006 TEEX


Always open the cylinder valve slowlyNever open an acetylene cylinder valve

more than 1.5 turns of the spindle, andpreferably no more than 3/4 of a turn


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39 2006 TEEX

Hose and hose connections

Replace hose with leaks, burns, wornplaces, defects

When parallel lengths of oxygen andfuel hose are taped together, not morethan 4 of 12 inches covered by tape


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40 2006 TEEX

Test Your Knowledge

How long must a firewatch continue?

A radius of 35 feet.How far away must

combustible materialsbe kept from welding?

Who is responsible formaking fire watchers

available?During work in confinedspaces, what must beleft outside?

Gas cylinders & weldingmachines.

Supervisor.

At least 30 minutes.


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41 2006 TEEX

Examples & Diagnosis


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Subtitles & TransitionsFOR EXAMPLE


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Welding Osha

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