MK Products Weld Control - Manual (Page 3)

Weld Control Selector Guide - Page ii
SafEty COnSidERatiOnS
- Continued -
A container with unknown contents should
be cleaned (see paragraph above). Do
NOT depend on sense of smell or sight to
determine 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. 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
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. 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