INSTRUCTIONS for
PM-GST
POST-MIX HAND CUTTING TORCH
(See Fig. 2 for listing of available torch assemblies.)
These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the principles of operation and safe practices for oxy-fuel
gas equipment, we urge you to read our booklet “Precautions and Safe Practices for Gas Welding, Cutting and Heating,” Form 2035. Do NOT
permit untrained persons to install, operate, or maintain this equipment. DO NOT attempt to install or operate this equipment until you have read
and fully understand these instructions. If you do not fully understand these instructions, contact your supplier for further information.
The cutting torches covered by these instructions are listed by Underwriter’s Laboratories only when using parts manufactured by ESAB Welding
& Cutting Products to the specifications on file with Underwriter’s Laboratories, Inc., and when they are used in the gas service for which they are
designed and listed. The use of other parts voids the manufacturer’s warranty.
OPERATING INSTRUCTIONS
F-15-365-C
July, 2000
DO NOT use torch with any fuel gas except natural
gas or propane. Using other fuel gases can overheat and damage the torch which can cause personal injury.
The PM-GST Cutting Torch is a post mixed design permitting the oxygen and fuel gas to be mixed externally
near the exit end of the torch. No internal mixing of the
combustibles occurs in the torch. Highly efficient mixing
occurs due to the distribution of preheat gases and
shielding gases around the cutting oxygen stream. This
produces an extraordinarily long high-heat zone permitting high standoff of torch to workpiece, thus increasing
the life of the torch and nozzle.
The PM-GST was designed for manual cutting operations that require torch to be in the stand-by pilot flame
mode ready for immediate use, such as emergency hot
cast billet cutting. The PM-GST (Post-Mix-Gas Saving
Torch) provides substantial gas savings in pilot mode
but remains ready for cutting without the operator having to light the torch.
The PM-GST Cutting Torch can be used on hot or cold
material and because of intense preheat capability provides extremely fast starts and cutting speeds.
EQUIPMENT REQUIRED (See Fig. 1)
1. Hoses - To obtain the best performance from the
PM-GST Torch, use 1/2 -in. (12.7 mm) I.D. hose for
oxygen and 3/8-in. (9.5 mm) I.D. hose for fuel gas.
Attach 1/2-in. oxygen hose, such as P/N 2120399
(50-ft.) with proper size fittings (7/8"-14 right hand
threads) to the oxygen supply regulator. Attach
3/8-in. fuel gas hose (9/16-18 left hand threads) to
fuel gas supply regulator. Heat protection of hoses
is recommended when working over hot cutting areas. (Note: 3/8-in. I.D. oxygen hose may be used
but torch performance will be reduced. To use 3/8in. I. D. oxygen hose order P/N 18X19, “C” to “B”
adaptor.)
2. Regulation - High-Flow Two Outlet Regulation
Panel, P/N 2119101. Panel is complete with R-52
Oxygen regulator, oxygen filter, R-6702 Fuel Gas
Regulator, and H-16 Fuel Gas Safety Valve. It is
OSHA approved, preassembled, and ready for permanent or portable wall or column mounting.
3. Cutting Nozzles - Select desired nozzle from Cutting Data table.
OPTIONAL ACCESSORIES
1. Riding Skid, P/N 22073.
DO NOT position the torch with the pilot flame ignited close to any combustible materials. When pilot flame is ignited torch must be held firmly by the
operator or in a stand-by holding fixture.
Be sure this information reaches the operator.
You can get extra copies through your supplier.
CONNECTING
1. Before connecting, make sure all metal seating surfaces of hoses, torch, and regulators are not damaged and cleaned free of grease and oil.
2. Connect hoses (1 oxygen; 1 fuel gas) to the proper
fitting on the torch and to the manual valves down-
SAFETY PRECAUTIONS
These Safety Precautions are for your protection. They summarize precautionary information from the references listed
in Additional Safety Information section. Before performing any
installation or operating procedures, be sure to read and follow the safety precautions listed below as well as all other
manuals, material safety data sheets, labels, etc. Failure to observe Safety Precautions can result in injury or death.
PROTECT YOURSELF AND OTHERS - Some
welding, cutting and gouging processes are
noisy and require ear protection. Hot metal can
cause skin burns and heat rays may injure
eyes. Training in the proper use of the processes and equipment is essential to prevent
accidents. Also:
1. Always wear safety glasses with side shields in any work area,
even if welding helmets, face shields, or goggles are also required.
2. Wear flameproof gauntlet type gloves, heavy long-sleeve shirt,
cuffless trousers, high-topped shoes, and a welding helmet or
cap for hair protection, to protect against hot sparks and hot
metal. A flameproof apron may also be desirable as protection
against radiated heat and sparks.
3. Hot sparks or metal can lodge in rolled up sleeves, trousers
cuffs, or pockets. Sleeves and collars should be kept buttoned,
and open pockets eliminated from the front of clothing.
4. Protect other personnel from hot sparks with a suitable nonflammable partition or curtains.
5. Use goggles over safety glasses when chipping slag or grinding. Chipped slag may be hot and can travel considerable distances. Bystanders should also wear goggles over safety
glasses.
FIRES AND EXPLOSIONS - Heat from a flame
can act as an ignition source. Hot slag or sparks
can also cause fires or explosions. Therefore:
1. Remove all combustible materials well away from the work
area or completely cover the materials with a protective nonflammable covering. Combustible materials include wood,
cloth, sawdust, liquid and gas fuels, solvents, paints and coatings, paper, etc.
2. Hot sparks or hot metal can fall through cracks or crevices in
floors or wall openings and cause a hidden smoldering fire on
the floor below. Make certain that such openings are protected
from hot sparks and metal.
3. Do not weld, cut, or perform any other hot work on materials,
containers, or piping until it has been completely cleaned so
that no substances on the material can produce flammable or
toxic vapors. Do not do hot work on closed containers. They
may explode.
4. Have fire extinguishing equipment handy for instant use, such
as a garden hose, a pail of water or sand, or portable fire
extinguisher. Be sure you are trained in its use.
5. After completing operations, inspect the work area to be sure
that there are no hot sparks or hot metal which could cause a
later fire. Use fire watchers when necessary.
6. For additional information, refer to NFPA Standard 51B, “Fire
Prevention in Use of Cutting and Welding Processes”, which
is available from the National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269.
FUMES AND GASES - Fumes and gases, particularly in confined spaces, can cause discomfort or injury. Do not breathe fumes or
gases from welding or cutting, Therefore:
1. Always provide adequate ventilation in the work area by natural or mechanical ventilation means. Do not weld, cut, or gouge
on materials such as galvanized steel, stainless steel, copper,
zinc, lead, beryllium, or cadmium unless positive mechanical
ventilation is provided. Do not breathe fumes and gases from
these materials.
2. If you develop momentary eye, nose, or throat irritation while
operating, this is an indication that ventilation is not adequate.
Stop work at once and take necessary steps to improve ventilation in the work area. Do not continue to operate if physical
discomfort persists.
3. Refer to ANSI/ASC Standard Z49.1 listed below for specific
ventilation recommendations.
4. WARNING: This product, when used for welding or
1. Always have qualified personnel perform the installation,
troubleshooting, and maintenance work. Do not operate or
repair any equipment unless you are qualified to do so.
2. Keep all oxy-fuel equipment free of grease or oil. Grease, oil,
and other similar combustible materials, when ignited, can burn
violently in the presence of oxygen.
3. Do not abuse any equipment or accessories. Keep equipment
away from heat and wet conditions, oil or grease, corrosive
atmospheres and inclement weather.
4. Keep all safety devices in position and in good repair.
5. Use equipment for its intended purpose. Do not modify it in
any manner.
1. Use the proper gas for the process and use the proper pressure reducing regulator designed to operate from the compressed gas cylinder. Do not use adaptors to mount the regulator on the cylinder. Maintain hoses and fittings in good condition. Follow manufacturer’s operating instructions for mounting the regulator to the gas cylinder.
2. Always secure cylinders in an upright position by chain or strap
to suitable hand trucks, benches, walls, post, or racks. Never
secure cylinders to work tables or fixtures where they may
become part of an electrical circuit.
3. When not in use, keep cylinder valves closed. Have the valve
protection cap in place on top of the cylinder if no regulators is
installed. Secure and move cylinders by using suitable hand
trucks. Avoid rough handling of cylinders.
4. Locate cylinders away from heat, sparks, or flame of a welding, cutting, or gouging operation. Never strike an arc on a
cylinder.
5. For additional information, refer to CGA Standard P-1, “Precautions for Safe Handling of Compressed Gases in Cylinders:, which is available from the Compressed Gas Association, 1235 Jefferson Davis Highway, Arlington, VA 22202.
The following publications, which are available from the American
Welding Society, 550 N.W. LeJuene Road, Miami, FL 33126, are
recommended to you:
1. ANSI/AWS Z49.1 - “Safety in Welding and Cutting”.
2. AWS F4.1 - “Recommended Safe Practices for the Preparation for Welding and Cutting of Containers and Piping That
Have Held Hazardous Substances”/
3. AWS SP - “Safe Practices” - Reprint, Welding Handbook.
cutting, produces fumes or gases which
contain chemicals known to the State of
California to cause birth defects and, in
some cases, cancer. (California Health &
Safety Code §25249.5 et seq.)
EQUIPMENT MAINTENANCE - Faulty or improperly maintained equipment, such as torches, hoses
and regulators, can result in poor work, but even
more important, it can cause injury or death
through fires. Therefore:
GAS CYLINDER HANDLING - Gas cylinders, if mishandled, can rupture or explode violently. Sudden
rupture of a cylinder, valve or relief device can injure or kill you. Therefore:
ADDITIONAL SAFETY INFORMATION - For more
information on safe practices for oxy-fuel welding
and cutting equipment, ask your distributor for a
copy of “Precautions and Safe Practices for Gas
Welding, Cutting, and Heating”, Form 2035. Gas
apparatus safety guidelines are also available on
video cassettes from your distributor.
MEANING OF SYMBOLS - As used throughout
this manual: Means Attention! Be Alert! Your
safety is involved.
Means immediate hazards which, if not avoided,
will result in immediate, serious personal in-
jury or loss of life.
Means potential hazards which could result in
personal injury or loss of life.
Means hazards which could result in minor
personal injury.
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SP-GA 10/98
stream of the regulator. Tighten the connecting nuts
firmly using two wrenches to prevent damage to the
torch.
3. Assemble desired nozzle (see Table) to the torch
and tighten nozzle retaining nut firmly.
Never touch the nozzle to the work piece.
NOTE: The optimal amount of preheat oxygen is auto-
matically regulated by the torch. The pilot oxygen valve is used only to adjust the pilot flame.
Cutting: Preheating is done while cutting lever is fully
depressed. Position torch on the far side of steel to be
cut. While maintaining at least 4 in. nozzle-to-work standoff, position the flame on the edge of the steel. Pull torch
towards you to begin cutting.
ADJUSTING GAS PRESSURES
1. Depress the cutting lever fully. Adjust cutting oxygen regulator to the desired pressure (see Figure 1)
compensating for any line loss to the torch through
the hose and valve. Then immediately release the
lever.
2. Adjust fuel gas regulator to provide 20 psig at the
torch with flow.
TESTING FOR LEAKS
The system should be thoroughly tested for leaks after
it is first hooked up, and at regular intervals thereafter.
With the system pressurized down to the shutoff valves,
apply Leak Test Solution suitable for oxygen service,
such as P/N 998771 (8 oz. container), on all joints and
connections. Bubbling of the solution indicates leakage.
If leakage is detected, tighten the connection. If this does
not stop leakage, then shut off the appropriate gas supply and open the torch valve to remove pressure from
the system. Break the leaky connection, wipe metal seating surface with a clean dry cloth, and examine them for
nicks and scratches. Remake the connection(s) and retest. Do not try to light the torch until you are satisfied
that all connections are gas tight.
After lighting the torch and adjusting the flames, use leak
test solution to check for leakage around hose connections at each valve and torch fitting.
LIGHTING AND FLAME ADJUSTMENT
Lighting Pilot Flame: Open fuel gas valve fully and light
the gas about 2 inches from the nozzle with a friction
lighter. DO NOT use a match. Use of a match can seriously burn your hand. Slowly open the pilot oxygen valve
until the pilot flame is adjusted as desired. For best performance, a flame extending just beyond the nozzle skirt
is recommended.
Cutting Flame Adjustment: While torch is lit in pilot
mode, point torch in a safe direction, hold torch firmly
and depress cutting lever fully. CAUTION: The torch will
tend to kick back from the force of the cutting oxygen.
Adjust fuel gas valve to give desired flame. Release cutting lever to return to pilot mode. Depress cutting lever
several times, both slowly and quickly to ensure pilot
flame is set properly. If torch extinguishes itself when
lever is released, open pilot oxygen valve slightly to increase pilot oxygen flow, relight torch and readjust pilot
oxygen valve.
NOTE: The flame is hottest at the edge of the cutting
oxygen stream. Placing the edge of the cutting
oxygen stream on the edge of the steel will give
the fastest starts.
Torch head, nozzle, and nozzle nut become VERY
hot while pilot flame is on and remain hot for several minutes after torch is turned off. Do NOT allow
hot torch to contact anything flammable.
SHUTTING OFF
1. Release cutting oxygen lever.
2. Close the pilot oxygen and fuel gas valves.
If operations are to be stopped for a half-hour or more,
pressure should be released from all regulators in the
following order:
1. Close station valve of each gas supply.
2. Open all torch shutoff valves.
3. When pressure on each regulator gauge drops down
to zero, back out regulator pressure-adjusting screw.
4. Close torch shutoff valves.
OPERATING PRECAUTIONS
Flow: There must be proper flow of gases for safe op-
eration and full performance. This requires the following
three conditions: (1) the regulators that determine the
inlet pressure to the hoses must be set to the correct
pressure: (2) the hoses and their connectors must have
adequate capacity for the job (hoses that are too long,
too small or have connectors with small passageways
can cause problems); and (3) the throttle valves on the
torch must be adjusted with the procedure shown in these
instructions.
NOTE: Items (1) and (2) can be checked by measuring
the gas pressures at the torch. Gauge adaptors
are available for this purpose.
Backfire: Improper operation of the torch may cause
the flames to go out with a loud “pop”. Such a backfire
may be caused by contact of nozzle with the work, by
the use of incorrect gas pressures or by leakage at the
cutting nozzle seats due to dirt or nicks on the seats or
to a loose nozzle nut.
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