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Safety considerations, Electric arc welding equipment – MK Products Cobramatic 42VAC User Manual

Page 3

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Cobramatic

®

Safety - page i

SAFETY CONSIDERATIONS

ELECTRIC ARC WELDING EQUIPMENT

CAUTION : READ BEFORE ATTEMPTING INSTALLATION, OPERATION

OR MAINTENANCE OF THIS EQUIPMENT

1-1 INTRODUCTION
This equipment is intended for ultimate

application by commercial/industrial users

and for operation by persons trained and

experienced in the use and maintenance of

welding equipment. Operation should not be

undertaken without adequate training in the

use of such equipment. Training is available

from many public and private schools or similar

facilities.
Safe practices in the installation, operation

and maintenance of this equipment requires

proper training in the art, a careful study of the

information provided with the equipment, and

the use of common sense. Rules for safe use

are generally provided by suppliers of welding

power sources, compressed gas suppliers,

and electrode suppliers. Careful compliance

with these rules will promote safe use of this

equipment.
The following Safety Rules cover some of the

more generally found situations. READ THEM

CAREFULLY. In case of any doubt, obtain

qualified help before proceeding.
1-2 GENERAL PRECAUTIONS
A. B

urn

P

revention

ELECTRIC ARC WELDING PRODUCES

HIGH INTENSITY HEAT AND ULTRAVIOLET

RADIANT ENERGY WHICH MAY CAUSE

SERIOUS AND PERMANENT EYE DAMAGE

AND WHICH MAY DAMAGE ANY EXPOSED

SKIN AREAS.
Wear helmet with safety goggles or glasses

with side shields underneath, appropriate filter

lenses or plates (protected by clear cover

glass). This is a must for welding or cutting

(and chipping) to protect the eyes from radiant

energy and flying metal. Replace cover glass

when broken, pitted, or spattered.
Medical first aid and eye treatment. First aid

facilities and a qualified first aid person should

be available for each shift unless medical

facilities are close by for immediate treatment

of flash burns of the eyes and skin burns.
Wear protective clothing - leather (or asbestos)

gauntlet gloves, hat, and high safety-toe shoes.

Button shirt collar and pocket flaps, and wear

cuffless trousers to avoid entry of sparks and

slag.
Avoid oily or greasy clothing. A spark may

ignite them.
Flammable hair preparations should not be

used by persons intending to weld or cut.
Hot metal such as electrode stubs and work

pieces should never be handled without gloves.

Ear plugs should be worn when working on

overhead or in a confined space. A hard hat should

be worn when others work overhead.
B. t

oxic

F

ume

P

revention

WARNING: The use of this product may result

in exposure to chemicals known to the State of

California to cause cancer and birth defects or

other reproductive harm.
Adequate ventilation. Severe discomfort, illness

or death can result from fumes, vapors, heat, or

oxygen enrichment or depletion that welding (or

cutting) may produce. Prevent them with adequate

ventilation. NEVER ventilate with oxygen.
Lead-, cadmium-, zinc-, mercury-, beryllium-bearing

and similar materials, when welded or cut, may

produce harmful concentrations of toxic fumes.

Adequate local exhaust ventilation must be used,

or each person in the area, as well as the operator,

must wear an air-supplied respirator. For beryllium,

both must be used.
Metals coated with or containing materials that emit

toxic fumes should not be heated unless coating

is removed form the work surface, the area is well

ventilated, or the operator wears an air-supplied

respirator.
Work in a confined space only while it is being

ventilated and, if necessary, while wearing an air-

supplied respirator.
Gas leaks in a confined space should be avoided.

Leaked gas in large quantities can change oxygen

concentration dangerously. Do not bring gas

cylinders into a confined space.
Leaving confined space, shut OFF gas supply at

source to prevent possible accumulation of gases

in the space if downstream valves have been

accidentally opened or left open. Check to be sure

that the space is safe before reentering it.
Vapors from chlorinated solvents can be

decomposed by the heat of the arc (or flame) to

form PHOSGENE, a highly toxic gas, and other

lung and eye irritating products. The ultraviolet

(radiant) energy of the arc can also decompose

trichloroethylene and perchloroethylene vapors

to form phosgene. DO NOT WELD or cut where

solvent vapors can be drawn into the welding or

cutting atmosphere or where the radiant energy can

penetrate to atmospheres containing even minute

amounts of trichloroethylene or perchloroethylene.
c. F

ire

And

e

xPlosion

P

revention

Causes of fire and explosion are: combustibles

reached by the arc, flame, flying sparks, hot slag,

or heated material, misuse of compressed gases

and cylinders, and short circuits.
BE AWARE THAT flying sparks or falling slag can

pass through cracks, along pipes, through windows

or doors, and through wall or floor openings,

out of sight of the goggled operator. Sparks

can fly many feet.
To prevent fires and explosion:
Keep equipment clean and operable, free of

oil, grease, and (in electrical parts) of metallic

particles that can cause short circuits.
If combustibles are in area, do NOT weld or

cut. Move the work if practicable, to an area

free of combustibles. Avoid paint spray rooms,

dip tanks, storage areas, ventilators. If the

work cannot be moved, move combustibles at

least 35 feet away, out of reach of sparks and

heat; or protect against ignition with suitable

and snug-fitting, fire-resistant covers or shields.
Walls touching combustibles on opposite

sides should not be welded on (or cut).

Walls, ceilings, and floor near work should be

protected by heat-resistant covers or shields.
Fire watcher must be standing by with suitable

fire extinguishing equipment during and for

some time after welding or cutting if:
1. Appreciable combustibles (including building

construction) are within 35 feet.
2. Appreciable combustibles are further than

35 feet, but can be ignited by sparks.
3. Openings (concealed or visible) in floors or

walls within 35 feet may expose combustibles

to sparks.
4. Combustibles adjacent to walls, ceilings,

roofs, or metal partitions can be ignited by

radiant or conducted heat.
Hot work permit should be obtained before

operation to ensure supervisor’s approval that

adequate precautions have been taken.
After work is done, check that area is free of

sparks, glowing embers, and flames.
An empty container that held combustibles,

or that can produce flammable or toxic vapors

when heated, must never be welded on or

cut, unless container has first been cleaned in

accordance with industry standards.
This includes: a thorough steam or caustic

cleaning (or a solvent of water washing,

depending on the combustible’s solubility),

followed by purging and inerting with nitrogen

or carbon dioxide, and using protective

equipment.
Water-filling just below working level may

substitute for inerting.
A container with unknown contents should

be cleaned (see paragraph above). Do NOT

depend on sense of smell or sight to determine