You Know Welding Cutting Safety Etc

8/8/2019 You Know Welding Cutting Safety Etc

1/136

You know welding cutting

safety etc.

Or should it read justSAFETY ETC. BEFORE WE STARTW hat never seen a girl with a welders

mask on before!

P bar Y Safety Consultants Alberta Canada


2/136

Welding On top of

safety what are we talking

about in theU S A



3/136

G eneral Requirements

Fire Prevention and ProtectionBasic PrecautionsFire hazards If the object to be welded or cut cannot readily be

moved, all movable fire hazards in the vicinityshall be taken to a safe place .

G uards If the object to be welded or cut cannot be moved

and if all the fire hazards cannot be removed, thenguards shall be used to confine the heat, sparks,and slag, and to protect the immovable firehazards.



4/136

S ubpart Q

1910.251 - Definitions1910.252 - General Requirements

1910.253 - Oxygen-fuel gaswelding and cutting

1910.254 - Arc welding and cutting

1910.255 - Resistance welding



5/136

Incorporated by reference as

specified in S ec. 1910.6The following material is available for purchase fromthe American Welding Society (AWS), 550 NW,LeJeune Road, P.O. Box 351040, Miami FL 33135 :

AWS A3.0 (1969) Terms and Definitions, IBR approvedfor 1910.251(c).

AWS A6.1 (1966) Recommended S afe Practices for G asS hielded Arc Welding, IBR approved for

1910.254(d)(1).AWS B3.0-41 S tandard Qualification Procedure, IBRapproved for 1910.67(c)(5)(i).



6/136

Incorporated by reference as

specified inS

ec. 1910.6AWS D1.0-1966 Code for Welding in BuildingConstruction, IBR approved for 1910.27(b)(6).

AWS D2.0-69 S pecifications for Welding Highway and

Railway Bridges, IBR approved for 1910.67(c)(5)(iv).AWS D8.4-61 Recommended Practices for AutomotiveWelding Design, IBR approved for 1910.67(c)(5)(ii).

AWS D10.9-69 S tandard Qualification of Welding

Procedures and Welders for Piping and Tubing, IBRapproved for 1910.67(c)(5)(iii).



7/136

O ther Related OS HA S tandards

1910.102 - Acetylene1910.104 - Ox ygen

1926.350 - G as welding and cutting1926.351 - Arc welding and cutting1926.352 - Fire prevention1926.353 - Ventilation and protection in welding,cutting, and heating1926.354 - Welding, cutting, and heating in wayof preservative coatings



8/136

N FPA S tandardsN FPA 10 - Portable Fire E x tinguishersN FPA 50 - Bulk Ox ygen S ystems at Consumer S itesN FPA 51 - Ox ygen- Fuel G as S ystems for WeldingN FPA 51A - Acetylene Cylinder Charging PlantsN FPA 51B - Fire Prevention for Cutting and WeldingN FPA 70 - N ational Electric CodeN FPA 306 - Control of G as Hazards on VesselsN FPA 327 - Cleaning or S afeguarding of S mall Tanksand Containers



9/136

Definitions

Welder" and "welding operator" mean anyoperator of electric or gas welding andcutting equipment.

"Approved" means listed or approved by a

nationally recognized testing laboratory.



10/136


Fire Prevention and ProtectionBasic Precautions

Restrictions If the requirements stated in fire hazards

and guards sections cannot be followedthen welding and cutting shall not be

performed.



11/136

G eneral RequirementsFire Prevention and Protection

S pecial Precautions

S uitable firee x tinguishers shall bemaintained in a state of readiness

Fire Watchers arerequired whenever welding and cutting isperformed in locationswhere other than aminor fire might develop



12/136


Fire Prevention and ProtectionS pecial PrecautionsFire Watchers are also required when: Appreciable combustible materials, in

building construction or contents, are closer than 35 feet to the point of operation

Appreciable combustible materials more than35 feet away but are easily ignited by sparks

A fire watch shall be maintained for at leastone half hour after the completion of weldingor cutting operations



13/136


Fire Prevention and ProtectionS pecial PrecautionsCutting or welding shall not be permitted inthe following situations: In areas not authorized by management In sprinkled buildings when protection is

impaired

In the presence of e x plosive atmospheres



14/136


W elding or cutting containers Will be cleaned so thoroughly as to make

absolutely certain that there are no flammablematerials present or any substances such asgreases, tars, acids, or other materials whichwhen subjected to heat, might produce flammableor to x ic vapors. have been

Any pipe lines or connections to the drumor vessel shall be disconnected or blanked



15/136


Confined spaces .

When arc welding is to be suspended for any substantial period of time, such asduring lunch or overnight, all electrodesshall be removed from the holders and theholders carefully located so that accidentalcontact cannot occur and the machine bedisconnected from the power source



16/136


Confined spaces In order to eliminate the possibility of gas escaping

through leaks or improperly closed valves, whengas welding or cutting, the torch valves shall beclosed and the gas supply to the torch positivelyshut off at some point outside the confined areawhenever the torch is not to be used for a

substantial period of time, such as during lunchhour or overnight . Where practicable, the torch and hose shall also

be removed from the confined space



17/136


18/136

Personnel Protection



19/136

G eneral RequirementsProtection of Personnel

E ye protection Helmets or hand shields shall be used during all

arc welding or arc cutting operations, ex

cludingsubmerged arc welding. Helpers or attendantsshall be provided with proper eye protection.

G oggles or other suitable eye protection shall beused during all gas welding or o x ygen cutting

operations. S pectacles without side shields, withsuitable filter lenses are permitted for use duringgas welding operations on light work, for torchbrazing or for inspection.



20/136


Protection of PersonnelW elding Operation | Shade No .

Shielded metal-arc welding -

1/16 -, 3/32 -, 1/8 -, 5/32 -inch electrodes 10Gas-shielded arc welding (nonferrous) -

1/16 -, 3/32 -, 1/8 -, 5/32 -inch electrodes 11

Gas-shielded arc welding (ferrous) -

1/16 -, 3/32 -, 1/8 -, 5/32 -inch electrodes 12

Soldering 2

T orch brazing 3 or 4

H eavy cutting, 6 inches and over 5 or 6



21/136


Protection of PersonnelAirline respirators In circumstances for

which it is impossibleto provide suchventilation

SCBA

In IDL H Atmospheres



22/136

G eneral RequirementsConfined S paces

Confined space means a relatively small or restricted space such as a tank, boiler, pressurevessel, or small compartment of a ship

Ventilation is a prerequisite to work inconfined spaces



23/136


Securing cylinders and machinery When welding or cutting is being performed in

any confined spaces the gas cylinders andwelding machines shall be left on the outside.



24/136


Lifelines Where a welder must enter a confined space

through a manhole or other small opening,means shall be provided for quickly removinghim in case of emergency.

An attendant with a pre-planned rescueprocedure shall be stationed outside to observethe welder at all times and be capable of puttingrescue operations into effect .



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26/136

G eneral RequirementsHealth Protection and Ventilation

Mechanical ventilation is required whenwelding or cutting is done with materials inthis section

Materials such as fluorine compounds,zinc, lead, beryllium, cadmium, mercury,

cleaning compounds and stainless steelare particularly hazardous and specificcontrol requirements



27/136

Ox ygen-fuel gas weldingand cutting 1910.253

Flammable mi x ture

Mix tures of fuel gases and air or o x ygen

may be e x plosive and shall be guardedagainst.

Cutting torch temperatures e x ceed 5000degrees F



28/136


M aximum pressure

Under no condition shall acetylene be

generated, piped or utilized at a pressurein e x cess of 15 psig (103 kPa gaugepressure) or 30 psia (206 kPa absolute)



29/136


ApparatusO nly approved

apparatus such astorches, regulators or pressure-reducing valves, acetylenegenerators, and manifolds shall be used.



30/136

Ox ygen-fuel gas welding

and cutting 1910.253Cylinders and containersAll portable cylinders usedfor the storage andshipment of compressedgases shall be constructedand maintained inaccordance with theregulations of the U. S .Department of Transportation, 49 CFRParts 171-179.



31/136


and cutting 1910.253Design of AcetyleneCylinder

Filled with CalciumSilicate



32/136


Cylinders and containersCompressed gas cylinders shall be legiblymarked, for the purpose of identifying the gascontent, with either the chemical or the tradename of the gas.S uch marking shall be by means of stenciling,

stamping, or labeling, and shall not be readilyremovable. Whenever practical, the markingshall be located on the shoulder of the cylinder.



33/136


34/136


Storage of cylinders-generalAssigned storage spaces shall be located wherecylinders will not be knocked over or damagedby passing or falling objects, or subject totampering by unauthorized persons.

Cylinders shall not be kept in unventilated

enclosures such as lockers and cupboards.Empty cylinders shall have their valves closed.



35/136


and cutting 1910.253

Oxygen and acetylene cylinders instorage must be separated by 20 feet

Or a 1/2 hour fire wall ( 5 ft.)



36/136


Valve protection caps, where cylinder isdesigned to accept a cap, shall always bein place, hand-tight, e x cept when cylindersare in use or connected for use.



37/136


Fuel-gas cylinder storage .

Inside a building, cylinders, e x cept those inactual use or attached ready for use, shall belimited to a total gas capacity of 2,000 cubic feet(56 m(3)) or 300 pounds (135.9 kg) of liquefiedpetroleum gas.



38/136


Fuel-gas cylinder storage .For storage in e x cess of 2,000 cubic feet (56m(3)) total gas capacity of cylinders or 300pounds (135.9 kg) of liquefied petroleum gas, aseparate room or compartment shall beprovided, or cylinders shall be kept outside or ina special building.

S pecial buildings, rooms or compartments shallhave no open flame for heating or lighting andshall be well ventilated.



39/136


Oxygen storageOx ygen cylinders shall not be stored near

highly combustible material, especially oiland grease.



40/136


Operating procedures .

Cylinders, cylinder valves, couplings,

regulators, hose, and apparatus shall bekept free from oily or greasy substances.Ox ygen cylinders or apparatus shall not behandled with oily hands or gloves.



41/136


Operating proceduresWhen transporting cylinders by a crane or derrick, a cradle, boat, or suitable platformshall be used. S lings or electric magnets shall not be used

for this purpose.

Valve-protection caps, where cylinder isdesigned to accept a cap, shall always be inplace.



42/136


Valve-protection caps shall not be used for lifting cylinders from one vertical positionto another. Bars shall not be used under valves or valve-

protection caps to pry cylinders loose whenfrozen to the ground or otherwise fi x ed; theuse of warm (not boiling) water is

recommended. Valve-protection caps are designed to protect

cylinder valves from damage.



43/136


Unless cylinders are secured on a specialtruck, regulators shall be removed andvalve-protection caps, when provided for,shall be put in place before cylinders aremoved.



44/136


Cylinders not having fi x ed hand wheelsshall have keys, handles, or nonadjustablewrenches on valve stems while thesecylinders are in service. In multiple cylinder installations only one key

or handle is required for each manifold.

Cylinder valves shall be closed beforemoving cylinders.



45/136


Cylinder valves shall be closed when workis finished.

Valves of empty cylinders shall be closed.



46/136


Cylinders shall be kept far enough awayfrom the actual welding or cuttingoperation so that sparks, hot slag, or flamewill not reach them, or fire-resistant shieldsshall be provided.Cylinders shall not be placed where theymight become part of an electric circuit.



47/136


Cylinders shall be kept away from radiators,piping systems, layout tables, etc., that may beused for grounding electric circuits such as for

arc welding machines.Any practice such as the tapping of an electrodeagainst a cylinder to strike an arc shall beprohibited.

Cylinders shall never be used as rollers or supports, whether full or empty.



48/136


Before connecting the regulator to thecylinder valve, the valve shall be openedslightly for an instant and then closed.

Always stand to one side of the outletwhen opening the cylinder valve.



49/136


Protective equipment, hose, andregulators

Equipment shall be installed and used onlyin the service for which it is approved andas recommended by the manufacturer.



50/136


Piping protective equipment .

The fuel-gas and o x ygen piping systems,including portable outlet headers shallincorporate the protective equipment

Backflow of o x ygen into the fuel-gas supplysystem

Passage of a flash back into the fuel-gas supplysystem



51/136


H ose and hose connections .Hose for o x y-fuel gas service shall comply withthe S pecification for Rubber Welding Hose,

1958, Compressed G as Association and Rubber Manufacturers AssociationWhen parallel lengths of o x ygen and acetylene

hose are taped together for convenience and to

prevent tangling, not more than 4 inches (10.2cm) out of 12 inches (30.5 cm) shall be coveredby tape.



52/136


H ose and hose connectionsHose connections shall comply with the S tandard HoseConnection S pecifications, 1957, Compressed G as

Association.Hose connections shall be clamped or otherwisesecurely fastened in a manner that will withstand, withoutleakage, twice the pressure to which they are normallysubjected in service

Hose showing leaks, burns, worn places, or other defects rendering it unfit for service shall be repaired or replaced.



53/136


Pressure-reducing regulators .

Pressure-reducing regulatorsshall be used only for the gasand pressures for which theyare intended.

When regulators or parts of regulators, including

gages, need repair, the work shall be performedby skilled mechanics who have been properlyinstructed.



54/136


55/136

Arc welding and cutting

1910.254In the arc weldingprocess, an electriccurrent passing throughthe welding rod or electrode is forced to

jump or arc across agap. The resulting arcproduces the intenseheat necessary for thearc welding and cuttingoperation.



56/136


1910.254Arc welding is used tofabricate nearly all

types of carbon andalloy steels , thecommon nonferrousmetals, and isindispensable in therepair and reclamationof metallic machineparts



57/136

Arc welding and cutting1910.254

E quipment selection .

Welding equipment shall be chosen for

safe application to the work to be doneInstallation .

Welding equipment shall be installed

safely



58/136


Instruction .

Workmen designated to operate arc

welding equipment shall have beenproperly instructed and qualified to operatesuch equipment



59/136


60/136


1910.254Terminals for welding leads

should be protectedfrom accidentalelectrical contact bypersonnel or by

metal objects i.e.,vehicles, cranehooks, etc.



61/136


Workmen assigned to operate or maintainarc welding equipment shall be acquaintedwith the requirements of this section andwith 1910.252If doing gas-shielded arc welding, alsoRecommended S afe Practices for G as-S hielded Arc Welding, A6.1-1966,

American Welding S ociety



62/136


Electrode holders. Electrode holders when not in use shall be so

placed that they cannot make electrical

contact with persons, conducting objects, fuelor compressed gas tanks.

Electric shock. Cables with splices within 10 feet (3 m) of the

holder shall not be used. The welder shouldnot coil or loop welding electrode cablearound parts of his body.



63/136

Resistance Welding1910.255

InstallationT hermal protection

Personnel

Guarding

Spot and seam weldingmachines

Voltage

Capacitor welding

Interlocks

Guarding

Shields

Foot switches

Stop buttons

Safety pins

Grounding



64/136

O ther Information

American Welding S ociety www.aws.orgN

ational WeldingS

upply Association www.welderssupply.com



65/136

1926.350G as welding and cutting

T ransporting, moving, and storing compressedgas cylinders V alve protection caps shall be in place and

secured

When cylinders are hoisted, they shall be

secured on a cradle, slingboard, or pallet.They shall not be hoisted or transported bymeans of magnets or choker slings



66/136


T ransporting, moving, and storing compressedgas cylinders Cylinders shall be moved by tilting and rolling

them on their bottom edges. They shall not beintentionally dropped, struck, or permitted tostrike each other violently

When cylinders are transported by poweredvehicles, they shall be secured in a verticalposition



67/136


T ransporting, moving, and storing compressedgas cylinders Valve protection caps shall not be used for

lifting cylinders from one vertical position toanother

Bars shall not be used under valves or valveprotection caps to pry cylinders loose when

frozen Warm, not boiling, water shall be used to thaw

cylinders loose



68/136


T ransporting, moving, and storing compressedgas cylinders )(6) Unless cylinders are firmly secured on a

special carrier intended for this purpose,regulators shall be removed and valveprotection caps put in place before cylindersare moved



69/136


T ransporting, moving, and storing compressedgas cylinders )( A suitable cylinder truck, chain, or other

steadying device shall be used to keepcylinders from being knocked over while inuse

When work is finished, when cylinders areempty, or when cylinders are moved at anytime, the cylinder valve shall be closed 6)



70/136


71/136


T ransporting, moving, and storing compressedgas cylinders )( Ox ygen cylinders in storage shall be

separated from fuel-gas cylinders or combustible materials (especially oil or grease), a minimum distance of 20 feet (6.1m) or by a noncombustible barrier at least 5feet (1.5 m) high having a fire-resistancerating of at least one-half hour.



72/136


T ransporting, moving, and storing compressedgas cylinders )( Inside of buildings, cylinders shall be stored in

a well-protected, well-ventilated, dry location,at least 20 feet (6.1 m) from highlycombustible materials such as oil or e x celsior

Cylinders should be stored in definitelyassigned places away from elevators, stairs,or gangways



73/136


T ransporting, moving, and storing compressedgas cylinders )( Assigned storage places shall be located

where cylinders will not be knocked over or damaged by passing or falling objects, or subject to tampering by unauthorized persons

Cylinders shall not be kept in unventilatedenclosures such as lockers and cupboards



74/136


75/136


Placing Cylinders Cylinders shall be placed where they cannot

become part of an electrical circuit. Electrodesshall not be struck against a cylinder to strikean arc



76/136


Placing Cylinders Fuel gas cylinders shall be placed with valve

end up whenever they are in use

They shall not be placed in a location wherethey would be subject to open flame, hot

metal, or other sources of artificial heat



77/136


Placing Cylinders Cylinders containing o x ygen or acetylene or

other fuel gas shall not be taken into confinedspaces (c)



78/136


T reatment of cylinders Cylinders, whether full or empty, shall not be

used as rollers or supports

N o person other than the gas supplier shallattempt to mi x gases in a cylinder

N o damaged or defective cylinder shall beused d )



79/136


U se of fuel gas Before a regulator to a cylinder valve is

connected, the valve shall be opened slightlyand closed immediately

This action is generally termed "cracking" and

is intended to clear the valve of dust or dirtthat might otherwise enter the regulator (d)(2)


1926 350


80/136


Use of fu el ga s

The cylinder valve shall always be openedslowly to prevent damage to the regulator

For quick closing, valves on fuel gas cylindersshall not be opened more than 1 1/2 turns


1926 350


81/136


Use of fu el ga s

When a special wrench is required, it shall beleft in position on the stem of the valve while

the cylinder is in use so that the fuel gas flowcan be shut off quickly in case of anemergency

In the case of manifolded or coupledcylinders, at least one such wrench shallalways be available for immediate use



82/136

1926 350


83/136


H ose Fuel gas hose and o x ygen hose shall be

easily distinguishable from each other

The contrast may be made by different colorsor by surface characteristics readilydistinguishable by the sense of touch

Ox ygen and fuel gas hoses shall not beinterchangeable



84/136

1926 350


85/136


H ose All hose in use, carrying acetylene, o x ygen,

natural or manufactured fuel gas, or any gasor substance which may ignite or enter intocombustion, or be in any way harmful toemployees, shall be inspected at thebeginning of each working shift

Defective hose shall be removed from service


1926 350


86/136


H ose Hose couplings shall be of the type that

cannot be unlocked or disconnected bymeans of a straight pull without rotary motion

Bo x es used for the storage of gas hose shallbe ventilated

Hoses, cables, and other equipment shall bekept clear of passageways, ladders and stairs


1926 350


87/136


Torches Clogged torch tip openings shall be cleaned

with suitable cleaning wires, drills, or other

devices designed for such purpose

Torches in use shall be inspected at thebeginning of each working shift for leakingshutoff valves, hose couplings, and tipconnections. Defective torches shall not beused


1926 350


88/136


Torches Torches shall be lighted by friction lighters or

other approved devices, and not by matchesor from hot work


1926 350


89/136


Regulators and gauges Ox ygen and fuel gas pressure regulators,

including their related gauges, shall be inproper working order while in use )


1926 350


90/136


Oil and grease hazards Ox ygen cylinders and fittings shall be kept

away from oil or grease

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

shall be kept free from oil or greasysubstances and shall not be handled with oilyhands or gloves


1926 351


91/136

1926.351 Arc welding and cutting

M anual electrode holders O nly manual electrode holders which are

specifically designed for arc welding andcutting, and are of a capacity capable of safely handling the ma x imum rated currentrequired by the electrodes, shall be used


1926 351


92/136


M anual electrode holders Any current-carrying parts passing through

the portion of the holder which the arc welder or cutter grips in his hand, and the outer surfaces of the jaws of the holder, shall befully insulated against the ma x imum voltageencountered to ground (b)


1926 351


93/136


W elding cables and connectors .

All arc welding and cutting cables shall be of the completely insulated, fle x ible type,capable of handling the ma x imum currentrequirements of the work in progress, takinginto account the duty cycle under which thearc welder or cutter is working


1926 351


94/136


W elding cables and connectors . O nly cable free from repair or splices for a

minimum distance of 10 feet from the cable

end to which the electrode holder isconnected shall be used

E x cept that cables with standard insulated

connectors or with splices whose insulatingquality is equal to that of the cable arepermitted )


1926 351


95/136


W elding cables and connectors When it becomes necessary to connect or

splice lengths of cable one to another,substantial insulated connectors of a capacity

If connections are effected by means of cablelugs, they shall be securely fastened together to give good electrical contact

E x posed metal parts of the lugs shall becompletely insulated


1926 351


96/136


Ground returns and machine grounding A ground return cable shall have a safe

current carrying capacity equal to or

ex

ceeding the specified max

imum outputcapacity of the arc welding or cutting unitwhich it services

When a single ground return cable servicesmore than one unit, its safe current-carryingcapacity


1926 351


97/136


Ground returns and machine grounding Pipelines containing gases or flammable

liquids, or conduits containing electricalcircuits, shall not be used as a groundreturn (c )(3)

When a structure or pipeline is employed as aground return circuit, it shall be determinedthat the required electrical contact e x ists at all

joints (c)(4)


1926 351


98/136


Ground returns and machine grounding All ground connections shall be inspected to

ensure that they are mechanically strong andelectrically adequate for the required current


1926 351


99/136


Operation instructions Employers shall instruct employees in the

safe means of arc welding and cutting

When electrode holders are to be leftunattended, the electrodes shall be removedand the holders shall be so placed or protected that they cannot make electricalcontact with employees or conducting objects


1926 351


100/136


Operating instructions Hot electrode holders shall not be dipped in

water

To do so may e x pose the arc welder or cutter to electric shock


1926 351


101/136


Operating instructions When the arc welder or cutter has occasion to

leave his work or to stop work for anyappreciable length of time, or when the arcwelding or cutting machine is to be moved,the power supply switch to the equipmentshall be opened

Any faulty or defective equipment shall bereported to the supervisor


1926 351


102/136


Shielding Whenever practicable, all arc welding and

cutting operations shall be shielded bynoncombustible or flameproof screens whichwill protect employees and other personsworking in the vicinity from the direct rays of the arc



103/136

1926 352


104/136

1926.352Fire Prevention

If the object to be welded, cut, or heatedcannot be moved and if all the fire hazardscannot be removed, positive means shallbe taken to confine the heat, sparks, andslag, and to protect the immovable firehazards from them )



105/136

1926 352


106/136


S uitable fire e x tinguishing equipment shallbe immediately available in the work areaand shall be maintained in a state of readiness for instant use


1926 352


107/136


When welding, cutting, or heating isperformed on walls, floors, and ceilings,since direct penetration of sparks or heattransfer may introduce a fire hazard to anadjacent area, the same precautions shallbe taken on the opposite side as are taken

on the side on which the welding is beingperformed



108/136

1926.352


109/136


For the elimination of possible fire in enclosedspaces as a result of gas escaping throughleaking or improperly closed torch valves, the

gas supply to the torch shall be positively shutoff at some point outside the enclosed spacewhenever the torch is not to be used or whenever the torch is left unattended for a

substantial period of time, such as during thelunch period


1926.352


110/136


O vernight and at the change of shifts, thetorch and hose shall be removed from theconfined spaceO pen end fuel gas and o x ygen hoses shallbe immediately removed from enclosedspaces when they are disconnected from

the torch or other gas-consuming device


1926.353


111/136

1926.353Ventilation & Protection

M echanical Ventilation Mechanical ventilation shall consist of either

general mechanical ventilation systems or

local e x haust systems (a )(2) G eneral mechanical ventilation shall be of

sufficient capacity and so arranged as toproduce the number of air changes necessaryto maintain welding fumes and smoke withinsafe limits


1926.353


112/136

1926.353Ventilation & Protection

M echanical Ventilation Local e x haust ventilation shall consist of

freely movable hoods intended to be placed

by the welder or burner as close aspracticable to the work

This system shall be of sufficient capacity andso arranged as to remove fumes and smokeat the source and keep the concentration of them in the breathing zone within safe limits


1926.353


113/136

9 6.353Ventilation & Protection

M echanical Ventilation Contaminated air e x hausted from a working

space shall be discharged into the open air or

otherwise clear of the source of intake air (5)

All air replacing that withdrawn shall be clean

and respirable


1926.353


114/136

Ventilation & ProtectionM echanical Ventilation Ox ygen shall not be used for ventilation

purposes, comfort cooling, blowing dust from

clothing, or for cleaning the work area (b)


1926.353


115/136

Ventilation & ProtectionW elding, cutting, and heating in confinedspaces Either general mechanical or local e x haust

ventilation shall be provided whenever welding, cutting, or heating is performed in aconfined space


1926.353


116/136

Ventilation & Protection

W elding, cutting, and heating in confined spaces When sufficient ventilation cannot be obtained

without blocking the means of access,employees in the confined space shall beprotected by air line respirators

An employee on the outside of such a confined

space shall be assigned to maintaincommunication with those working within it andto aid them in an emergency


1926.353


117/136

Ventilation & ProtectionW elding, cutting, and heating in confinedspaces "Lifelines.

Where a welder must enter a confined spacethrough a manhole or other small opening,

means shall be provided for quickly removinghim in case of emergency


1926.353


118/136

Ventilation & ProtectionW elding, cutting, and heating in confinedspaces An attendant with a pre-planned rescue

procedure shall be stationed outside toobserve the welder at all times and becapable of putting rescue operations intoeffect (c)


1926.353


119/136

Ventilation & ProtectionW elding, cutting, or heating of metals of toxicsignificance (c)(1) Welding, cutting, or heating in any enclosed

spaces involving the metals specified in thissubparagraph shall be performed with either general mechanical or local e x haustventilation )(1)(i)


1926.353


120/136

Ventilation & ProtectionW elding, cutting, or heating of metals of toxicsignificance (c)(1) Zinc-bearing base or filler metals or metals

coated with zinc-bearing materials Lead base metals

Cadmium-bearing filler materials

Chromium-bearing metals or metals coatedwith chromium-bearing materials c)(2)


1926.353


121/136

Ventilation & ProtectionW elding, cutting, or heating of metals of toxicsignificance (c)( Metals containing lead, other than as an

impurity, or metals coated with lead-bearingmaterials ( c)(2)(ii)

Cadmium-bearing or cadmium-coated basemetals (c)(2)(iii)


1926.353


122/136

Ventilation & ProtectionW elding, cutting, or heating of metals of toxicsignificance (c)( Metals coated with mercury-bearing metals

Beryllium-containing base or filler metals.Because of its high to x icity, work involving

beryllium shall be done with both locale x haust ventilation and air line respirators


1926.353


123/136

Ventilation & ProtectionW elding, cutting, or heating of metals of toxicsignificance ( Employees performing such operations in the

open air shall be protected by filter-typerespirators

E x cept that employees performing suchoperations on beryllium-containing base or filler metals shall be protected by air linerespirators



124/136

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Inert-gas metal-arc welding S ince the inert-gas metal-arc welding process

involves the production of ultra-violet radiationof intensities of 5 to 30 times that producedduring shielded metal-arc welding, thedecomposition of chlorinated solvents byultraviolet rays, and the liberation of to x ic fumes

and gases, employees shall not be permitted toengage in, or be e x posed to the process untilspecial precautions have been taken


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Ventilation & ProtectionInert-gas metal-arc welding The use of chlorinated solvents shall be kept

at least 200 feet, unless shielded, from the

e x posed arc, and surfaces prepared withchlorinated solvents shall be thoroughly drybefore welding is permitted on such surfaces


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Inert-gas metal-arc welding Employees in the area not protected from the arc

by screening shall be protected by filter lenses

When two or more welders are e x posed to eachother's arc, filter lens goggles of a suitable type

Hand shields to protect the welder againstflashes and radiant energy shall be used wheneither the helmet is lifted or the shield is removed


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Inert-gas metal-arc welding Welders and other employees who are

e x posed to radiation shall be suitablyprotected so that the skin is coveredcompletely to prevent burns and other damage by ultraviolet rays

Welding helmets and hand shields shall befree of leaks and openings, and free of highlyreflective surfaces


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Inert-gas metal-arc welding When inert-gas metal-arc welding is being

performed on stainless steel, requirementsshall be met to protect against dangerousconcentrations of nitrogen dio x ide


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General welding, cutting and heating Welding, cutting, and heating, not involving the

previous materials, may normally be donewithout mechanical ventilation or respiratoryprotective equipment, but where, because of unusual physical or atmospheric conditions, an

unsafe accumulation of contaminants ex

ists,suitable mechanical ventilation or respiratoryprotective equipment shall be provided


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General welding, cutting and heating Employees performing any type of welding,

cutting, or heating shall be protected bysuitable eye protective equipment


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Preservative Coatings

Before welding, cutting, or heating iscommenced on any surface covered by a

preservative coating whose flammability isnot known, a test shall be made by acompetent person to determine itsflammability

Preservative coatings shall be considered tobe highly flammable when scrapings burnwith e x treme rapidity (b)


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Precautions shall be taken to prevent ignitionof highly flammable hardened preservative

coatings

When coatings are determined to be highlyflammable, they shall be stripped from the

area to be heated to prevent ignition c)


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Protection against toxic preservativecoatings (c)(1)

In enclosed spaces, all surfaces covered withtox ic preservatives shall be stripped of all to x iccoatings for a distance of at least 4 inches fromthe area of heat application, or the employees

shall be protected by air line respirators )(2) In the open air, employees shall be protected by

a respirator


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The preservative coatings shall be removeda sufficient distance from the area to beheated to ensure that the temperature of theunstripped metal will not be appreciablyraised

Artificial cooling of the metal surroundingthe heating area may be used to limit thesize of the area required to be cleaned



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You Know Welding Cutting Safety Etc

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