Oxyacetylene
torches
Harkness career center
Complete torch assembly
Oxygen tanks
When full, can have up to 2400 psi
Attaches regulators using Right handed
threads
Tank should be labeled “Compressed
Oxygen”
-If tank is not labeled come and
exchange tank with proper ID
one
Never transport tank with out safety
cap on the valve
Acetylene tank
When full contains 250 psi
Regulator uses left hand
threads
Acetylene over 15 psi is
Unstable.
Porous mass inside tank
consists of Aston and Balsa
wood – to keep the Acetylene
stable
Should be stored standing up,
if laid down it must stand for
8 hours before using
Regulators
• Regulators are designed to control and
reduce high gas pressure from a cylinder or
pipeline, in one or two stages, to the working
pressure required for the equipment using it.
Safety Precaution
• Do not use any oils, thread sealers, or grease
on regulator fittings. They pose a fire /
explosion hazard.
Regulator Set – up cont.
 Before connecting a regulator to a cylinder
or pipeline, open (crack) cylinder valve for a
few seconds, allowing gas to force out any
possible foreign matter (dust, dirt, pollen,
etc.)
 Connect regulator inlet connection to
cylinder or pipeline and tighten it firmly
with a suitable regulator wrench.
Regulator Set – up cont.
•Connect and similarly tighten the hose
nut to regulator outlet and attach other
equipment as needed.
• CAUTION ! Do not force connections
that do not fit. Acetylene fittings are
LEFT – HANDED thread (usually
indicated by a line or slash mark on the
fitting).
Regulator Set – up cont.
• Test connections by applying a soap
solution of a capful (¼ oz.) of Ivory Liquid
detergent or equivalent per gallon of
water.
• Bubbles indicate leakage.
• If no bubbles appear, the system is ready
for use.
Flash back arresters
• Are mounted in-line between the lines and
the torch handle.
• Are to prevent the flame from reaching
the tanks in a case of a flash back. (flame
burns inside the handle)
The Oxyacetylene Torch
Mixing Handle (the cutting
torch handle)
•
Attach Torch Mixing
handle
• The torch mixing handle should be attached
to the hose end. Do not over tighten either
mixing handle or regulator end hose
connections.
• Where rubber o – ring seals are used hand
tightening is sufficient.
Regulator Set – up cont.
• Before opening cylinder valve, turn
adjusting screw to the left
(counterclockwise) until no spring tension
is felt.
• Never open cylinder valve until spring
tension on adjusting screw has been
released in this manner.
Regulator Set – up cont.
• SLOWLY open the cylinder or station valve,
to avoid a sudden pressure surge that may
damage internal regulator parts.
• DO NOT STAND IN FRONT OF OR BEHIND
THE REGULATOR WHILE OPENING THE
VALVE. Stand with the tank valve between
you and the regulator.
Regulator Set – up cont.
• Fully open the oxygen valve (it has a
double seating valve).
• Only open the acetylene tank valve ¼ to ½
of a turn (this makes it easy to close in the
event of an emergency).
Regulator Set – up cont.
• Slowly turn adjusting screw
clockwise until the outlet gauge
shows the desired working
pressure.
• Set acetylene regulator
pressure to 7 psi.
• Set oxygen pressure to about
15 psi.
Safety Precautions
• A regulator which is not working properly
should not be used until all required
repairs have been made and the unit has
been tested to ensure that it is in proper
operating condition.
• No repairs or maintenance should ever be
attempted by anyone not qualified to do
so.
Regulator Set – up cont.
• To prevent igniting explosive gas mixtures,
in the hoses or other equipment attached
to the regulator outlet, before lighting the
torch, purge the system.
• This is done by opening the equipment
valves (cutting handle, etc.), allowing gas
to flow for about 5 seconds per 50 feet of
hose.
Regulator Set – up cont.
• CAUTION !
• Do not purge gases in the presence of flame,
lit cigarettes, or other sources of ignition, or
towards persons.
The Spark Lighter
• Squeezing the handle moves a
piece of flint across a rough metal
surface thus producing a shower
of sparks.
Lighting the Torch
• Open the acetylene mixer valve a small
amount while operating a striker or a spark
lighter in front of the tip.
• KEEP THE TIP FACING IN A SAFE
DIRECTION. HAVE YOUR
WELDING GOGGLES IN POSITION.
Flame Adjustment
• When the acetylene ignites,
adjust the flame until it is
hovering about 1/8 in. from the
tip. Carbonized flame
Flame Adjustment cont.
• Immediately open the
attachment oxygen valve and
adjust the flame. By starting with
a neutral flame (long yellow
acetylene feather).
Flame Adjustment cont.
• In order to obtain a oxidized
flame slowly close the acetylene
valve until sharp blue tips are
present.
Making the Cut
• In an oxyacetylene torch, the preheating
flame is maintained at the tip through small
orifices or openings around the center
orifice.
• The preheating flame is held close to the
work at the point where the cut is to start.
Making the Cut cont.
• Hold the torch at a right angle to the work
with the preheat flames just clear of the
surface.
• When the spot has been heated to a bright
cherry red or hotter, depress the oxygen jet
lever.
Making the Cut cont.
• When the stream of pure oxygen strikes the
heated area, it will cut (burn) through the
steel.
• As soon as the cut starts, move the torch
along the work. Move as rapidly as the
cutting will allow. Keep the oxygen lever fully
depressed.
Making the Cut cont.
• If the cutting action stops, release the oxygen
lever and with the preheat flames (they burn
continuously), preheat again.
• Note how the cutting torch removes a
narrow kerf (cut) and how the molten metal
(slag) is blown out from beneath the work.
Shut Down
• Close cylinder valve whenever regulator is
not in use, as follows.
• Close the cylinder or station valve.
• Open the equipment valve to drain the
line towards a safe area.
• After gas is completely drained , release
adjusting screw and close equipment
valve.