3 arc welding – MK Products Cobra Gold Gooseneck User Manual

Page 3

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Cobra Gold Owner's Manual Page ii

Hollow castings or containers must be

vented before welding or cutting. They

can explode.
Explosive atmospheres. NEVER weld or

cut where the air may contain flammable

dust, gas, or liquid vapors (such as

gasoline).

D. Compressed Gas Equipment

The safe handling of compressed gas

equipment is detailed in numerous industry

publications. The following general rules

cover many of the most common situa-

tions.

1. Pressure Regulators

Regulator relief valve is designed to protect

only the regulator from overpressure; it is

not intended to protect any downstream

equipment. Provide such protection with

one or more relief devices.
Never connect a regulator to a cylinder

containing gas other than that for which the

regulator was designed.
Remove faulty regulator from service

immediately for repair (first close cylinder

valve). The following symptoms indicate

a faulty regulator:
Leaks - if gas leaks externally.
Excessive Creep - if delivery pressure

continues to rise with downstream valve

closed.
Faulty Gauge - if gauge pointer does

not move off stop pin when pressurized,

nor returns to stop pin after pressure

release.
Repair. Do NOT attempt repair. Send faulty

regulators for repair to manufacturer’s

designated repair center, where special

techniques and tools are used by trained

personnel.

2. Cylinders

Cylinders must be handled carefully to

prevent leaks and damage to their walls,

valves, or safety devices:
Avoid electrical circuit contact with cylinders

including third rails, electrical wires, or

welding circuits. They can produced short

circuit arcs that may lead to a serious

accident. (See 1-3C)
ICC or DOT marking must be on each

cylinder. It is an assurance of safety when

the cylinder is properly handled.
Identifying gas content. Use only cylinders

with name of gas marked on them; do not

rely on color to identify gas content. Notify

supplier if unmarked. NEVER DEFACE or

alter name, number, or other markings on a

cylinder. It is illegal and hazardous.
Empties: Keep valves closed, replace caps

securely; mark MT; keep them separate

from FULLS, and return promptly.
Prohibited use. Never use a cylinder or its

contents for other than its intended use,

NEVER as a support or roller.
Locate or secure cylinders so they cannot

be knocked over.
Passageways and work areas. Keep

cylinders clear of areas where they may

be stuck.
Transporting cylinders. With a crane, use

a secure support such as a platform or

cradle. Do NOT lift cylinders off the ground

by their valves or caps, or by chains, slings,

or magnets.
Do NOT expose cylinders to excessive heat,

sparks, slag, and flame, etc. that may cause

rupture. Do not allow contents to exceed 55

degrees C (130 degrees F.) Cool with water

spray where such exposure exists.
Protect cylinders, particularly valves from

bumps, falls, falling objects, and weather.

Replace caps securely when moving cylin-

ders.
Stuck valve. Do NOT use a hammer or wrench

to open a cylinder valve that cannot be opened

by hand. Notify your supplier.
Mixing gases. NEVER try to mix any gases

in a cylinder.
NEVER refill any cylinder.
Cylinder fittings should never be modified

or exchanged.

3. Hose

Prohibited use. Never use hose other than that

designed for the specified gas. A general hose

identification rule is: red for fuel gas, green for

oxygen, and black for inert gases.
Use ferrules or clamps designed for the hose

(not ordinary wire or other substitute) as a

binding to connect hoses to fittings.
No copper tubing splices. Use only standard

brass fittings to splice hose.
Avoid long runs to prevent kinks and abuse.

Suspend hose off ground to keep it from

being run over, stepped on, or otherwise

damaged.
Coil excess hose to prevent kinks and

tangles.
Protect hose from damage by sharp edges,

and by sparks, slag, and open flame.
Examine hose regularly for leaks, wear, and

loose connections. Immerse pressured hose

in water; bubbles indicate leaks
Repair leaky or worn hose by cutting area out

and splicing. Do NOT use tape.

4. Proper Connections

Clean cylinder valve outlet of impurities that

may clog orifices and damage seats before

connecting regulator. Except for hydrogen,

crack valve momentarily, pointing outlet away

from people and sources of ignition. Wipe

with a clean, lintless cloth.
Match regulator to cylinder. Before connect-

ing, check that the regulator label and cylinder

marking agree, and that the regulator inlet

and cylinder outlet match. NEVER Connect

a regulator designed for a particular gas

or gases to a cylinder containing any other

gas.
Tighten connections. When assembling

threaded connections, clean and smooth

seats where necessary. Tighten. If connection

leaks, disassemble, clean, and retighten,

using properly fitting wrench.
Adapters. Use a CGA adapter (available from

your supplier) between cylinder and regulator,

if one is required. Use two wrenches to

tighten adapter marked RIGHT and LEFT

HAND threads.
Regulator outlet (or hose) connections may

be identified by right hand threads for oxygen

and left hand threads (with grooved hex on

nut or shank) for fuel gas.

5. Pressurizing Steps:

Drain regulator of residual gas through

suitable vent before opening cylinder (or

manifold valve) by turning adjusting screw

in (clockwise). Draining prevents excessive

compression heat at high pressure seat by

allowing seat to open on pressurization.

Leave adjusting screw engaged slightly on

single-stage regulators.
Stand to side of regulator while opening

cylinder valve.
Open cylinder valve slowly so that regulator

pressure increases slowly. When gauge

is pressurized (gauge reaches regulator

maximum) leave cylinder valve in following

position: for oxygen and inert gases, open

fully to seal stem against possible leak;

for fuel gas, open to less than one turn to

permit quick emergency shut-off.
Use pressure charts (available from your

supplier) for safe and efficient recom-

mended pressure settings on regulators.
Check for leaks on first pressurization

and regularly thereafter. Brush with soap

solution. Bubbles indicate leaks. Clean

off soapy water after test; dried soap is

combustible.

E. User Responsibilities

Follow all Safety Rules.
Remove leaky or defective equipment from

service immediately for repair. Read and

follow user manual instructions.

F. Leaving Equipment

Unattended

Close gas supply at source and drain

gas.

G. Rope Staging-Support

Rope staging-support should not be used

for welding or cutting operation; rope may

burn.

1-3 ARC WELDING

Comply with precautions in 1-1, 1-2, and

this section. Arc Welding, properly done,

is a safe process, but a careless operator

invites trouble. The equipment carries high

currents at significant voltages. The arc is

very bright and hot. Sparks fly, fumes rise,

ultraviolet and infrared energy radiates,

weldments are hot, and compressed gases

may be used. The wise operator avoids

unnecessary risks and protects himself

and others from accidents.

A. Burn Protection

Comply with precautions in 1-2.
The welding arc is intense and visibly

bright. Its radiation can damage eyes,

penetrate lightweight clothing, reflect from

light-colored surfaces, and burn the skin

and eyes. Skin burns resemble acute

sunburn; those from gas-shielded arcs

are more severe and painful. DON’T

GET BURNED; COMPLY WITH PRECAU-

TIONS.

1. Protective Clothing

Wear long-sleeve clothing in addition to

gloves, hat, and shoes. As necessary,

use additional protective clothing such as

leather jacket or sleeves, flameproof apron,

and fire-resistant leggings. Avoid outer

garments of untreated cotton.

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