MK Products Cobramatic 42VAC - Manual (Page 4)

Cobramatic ® Safety - page ii
if it is safe to weld or cut.
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. c
omPressed
G
As
e
quiPment
The safe handling of compressed gas
equipment is detailed in numerous industry
publications. The following general rules cover
many of the most common situations.
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 cylinders.
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 connecting,
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 recommended
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. u
ser r esPonsiBilities
Follow all Safety Rules.
Remove leaky or defective equipment from
service immediately for repair. Read and follow
user manual instructions.
F. l
eAvinG
e
quiPment
u
nAttended
Close gas supply at source and drain gas.
G. r
oPe
s
tAGinG
-s
uPPort
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. B
urn
P
rotection
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.