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3.
PREPARING TO WELD/CUT
# #
WARNING! DANGER OF EXPLOSION. All parts which come into contact with acetylene or oxygen, including hands and tools, must be
free from oil or grease. If grease or oil is found on a cylinder, discontinue its use immediately and contact your gas supplier.
3.1.
Preparing the cylinder. Make sure that the cylinder to be used is safe and properly secured as noted in the safety precautions.
3.1.2
Whilst standing on one side 'crack' each cylinder valve. 'Cracking' is to quickly open and close the valve allowing gas to escape and
clear the valve of any foreign bodies.
3.2
CONNECTING GAS REGULATORS TO THE CYLINDERS.
NOTE: PRESSURE REGULATORS SHOULD BE TREATED AS PRECISION INSTRUMENTS AND SHOULD NOT BE JARRED OR KNOCKED.
3.2.1
Function of the regulators. Fitted to the outlets of the gas cylinder valves, the pressure regulators reduce the pressure of the gas
from cylinder pressure to the constant lower pressure required for the operation of the equipment. The left hand gauge indicates the
pressure in the cylinder. The right hand gauge indicates the pressure of the gas being delivered to the torch. Pressure reduction
within the regulator occurs in two stages.
3.2.2
Attach oxygen and acetylene regulators to the appropriate cylinders. On each gauge ensure the inlet filter is in place and is not
blocked or contaminated. If an '0' ring is fitted to the inlet, check for damage and replace if necessary with an '0' ring recommended
by the regulator manufacturer. Do not use any form of jointing paste or tape between regulators and cylinder valves. Before
attaching the gauges wipe the fittings with a clean dry cloth. Screw the union at the base of each regulator to the appropriate
cylinder by hand. Ensure that the guage is correctly orientated so as to be seen properly by the operator in use. To tighten, turn
CLOCKWISE for OXYGEN, and ANTI-CLOCKWISE for ACETYLENE. A wrench should be used to ensure tight connections.
3.2.3
Close the regulators by turning the adjusting screws anti-clockwise to relieve the pressure on the diaphragm before opening the
cylinder valve. If this is not done, pressure from the cylinder can damage the diaphragm and render the regulator inoperative.
3.2.4
The cylinder valve-to-regulator connection should be checked for leaks using an approved leak detection spray or soap and water
solution.
3.3
CONNECTING FLASH ARRESTORS AND HOSES TO THE GAS REGULATORS.
3.3.1
Connect a BLUE colour coded, OXYGEN flash arrestor to the outlet on the OXYGEN regulator. (As shown above, on the left).
3.3.2
Then, connect a BLUE colour coded hose to the BLUE, OXYGEN flash arrestor. (As shown above, on the left).
3.3.3
Connect a RED colour coded, ACETYLENE Flash arrestor to the outlet on the ACETYLENE regulator. (As shown above, on the right).
3.3.4
Then, connect a RED colour coded hose to the RED, ACETYLENE flash arrestor.(As shown above, on the right).
3.3.5
Tighten all nuts securely with a wrench. If any sign of oil or grease is found on the flash arrestors or regulators discontinue use
immediately.
Note:
New hoses contain a preservative powder which must be blown out before use.
3.3.6
Prior to attaching the torch, blow out both hoses to eliminate any particles or debris. Perform this on one hose at a time and in a well
ventilated area, otherwise you may create conditions for fire or explosion.
a. Turn the oxygen or acetylene regulator adjusting screw clockwise to allow 5psi to pass through hose.
b. Allow oxygen or acetylene to flow for approximately 10 seconds to purge each hose in turn.
3.4
ASSEMBLING THE TORCH FOR WELDING. (SGA2 & SGA6)
WARNING! The teflon seal on the welding attachment inlet must not be damaged or missing, otherwise gases will
# #
mix inside the torch and result in flashbacks or backfires. Always inspect the seal, coupling nut and torch head for damage or oil. If
either is found, discontinue use and contact your supplier.
3.4.1
Screw the chosen welding nozzle into the welding attachment making sure that it is fully tightened down.
3.4.2
Screw the welding attachment with nozzle attached onto the torch handle as shown below. Before fully tightening the ribbed nut,
check that the orientation of the gas valve knobs suits your normal welding practice. Adjust if necessary and fully tighten the ribbed nut.
fig.2
3.5
ASSEMBLING THE TORCH FOR CUTTING. (SGA6 ONLY)
#
WARNING! The teflon seal on the cutting attachment inlet must not be damaged or missing, otherwise gases will mix inside the
torch and result in flashbacks or backfires. Always inspect the seal, coupling nut and torch head for damage or oil. If either is
found, discontinue use and contact your supplier.
3.5.1
To change the cutting nozzle loosen and remove the nut which holds it in place and withdraw the nozzle. Slide the chosen cutting
nozzle through the nut and screw the assembly into the cutting attachment and fully tighten down.
3.5.2
Screw the cutting attachment with nozzle attached onto the torch handle as shown below. Before fully tightening the the ribbed
NOTE: THE
nut, adjust the orientation of the gas valve knobs so that they do not block the movement of the lever (B).
REGULATORS
SHOWN HERE
ARE NOT
SUPPLIED WITH
THE SGA2 OR
SGA6 BUT ARE
SHOWN HERE TO
ILLUSTRATE THE
REGULATORS
REQUIRED FOR
A TYPICAL
WELDING AND
CUTTING SET UP.
3.6
CONNECTING NON-RETURN VALVES AND HOSES TO THE TORCH.
3.6.1
Always fit non-return valves (not supplied) to the torch before connecting the respective hoses. Non-return valves have different direction
threads to ensure that they are fitted to the correct side of the torch. An OXYGEN non-return valve has a normal thread and will fit to the
blue coded side of the torch (See colour coding on valve knobs). An ACETYLENE non-return valve has a reverse thread and will fit to the
red coded side of the torch (See colour coding on valve knobs).
3.6.2
Connect the two hoses (not supplied) to the respective non-return valves fitted to the torch handle.
#
WARNING! If traces of oil or grease are found, DO NOT use. Contact your gas supplier immediately.
4.
WELDING OPERATION
Note:
These instructions are intended to describe the facilities and operation of the welding/cutting torch. They are not intended
to teach you how to weld or cut using oxyacetylene. If you have no experience of welding/cutting using oxyacetylene it is
essential that you seek training from a qualified person or approved training organisation.
4.1
Assemble the torch for welding as described in section 3.4 (See also fig.2)
4.2
SETTING THE GAS REGULATOR PRESSURES Close the regulators by turning the adjusting screws anti-clockwise to relieve the
pressure on the diaphragm before opening the cylinder valves. Slowly open the cylinder valve on the oxygen and acetylene bottles in
turn. As you do so the high pressure gauge (left hand) on each regulator will register the pressure in the cylinder to which it is attached.
4.2.1
Slowly open each regulator in turn by turning the adjusting knob clockwise. As you do so the outlet pressure gauge (right hand) on
each regulator will register the outlet pressure of gas being fed to the torch. Adjust the pressure according to the size of nozzle in
use and the thickness of the material to be cut or welded. Refer to section 7.2 in the chart overleaf.
WARNING! Never set acetylene regulator at a delivery pressure above 15psi (1 bar).
#
4.2.2
After adjusting the regulators to the desired operating pressures check connections for leaks using an approved leak detection solution.
Check for leaks at all connections. If a leak is found, tighten fitting more securely. If leak persists, discontinue use and call your supplier.
4.2.3
Briefly open and close the oxygen valve on the torch handle to check that the gas is flowing.
4.2.4
Similarly open and close the acetylene valve on the torch handle to check that the gas is flowing.
#
WARNING! Always use welding gloves and suitable eye protection when welding or cutting. Contact your local Sealey dealer for a
full range of protective equipment.
4.3
LIGHTING THE TORCH Ensure that the gas hoses will not be in the way of the torch when ignited. Ensure that the torch is facing
away from you before lighting.
4.3.1
Holding the torch in one hand and the striker in the other open the acetylene valve a 1/4 turn (the valve knob is colour coded red).
Operate the striker close to the tip to light the acetylene.
4.3.2
The first flame that appears will be an orange/yellow colour giving off a small amount of black smoke from its tip. If too much acetylene
is flowing the flame will be standing away from the tip of the torch making a roaring noise. In extreme cases this type of flame can
blow itself out. To correct such a flame reduce the amount of acetylene until the flame is 8 to 10 inches long with less black smoke.
4.3.3
Once the acetylene flame is set correctly begin to introduce oxygen by slowly opening the oxygen control valve on the torch (The
valve knob is colour coded blue). The flame will change to a whitish colour and the black smoke will disappear. This flame is not hot
enough for welding.
4.3.4
Add more oxygen to the flame by further opening the control knob until a brilliant neutral flame is achieved.
4.4
SHUTTING DOWN AND LEAVING SAFE Turn off the acetylene valve on the torch first and then turn off the oxygen valve a few
moments later. Note:Turning the gases off in the wrong order can cause damage to the torch.
4.4.1
Close both cylinder valves.
4.4.2
Drain gas from oxygen regulator by opening the oxygen valve on the torch handle. Similarly drain gas from the acetylene regulator.
4.4.3
Release the adjusting knobs on the regulators. This is done by turning them anti-clockwise.
5.
CUTTING OPERATION
Note:
These instructions are intended to describe the facilities and operation of the welding/cutting torch. They are not intended
to teach you how to weld or cut using oxyacetylene. If you have no experience of welding/cutting using oxyacetylene it is
essential that you seek training from a qualified person or approved training organisation.
5.1
Assemble the torch for cutting as described in section 3.3 (See also fig.3)
5.2
GAS CONTROL WHEN USING THE CUTTING SET-UP
The control of the oxygen and acetylene flows on a cutting set-up differs from a welding set-up in the following ways:
5.2.1
The oxygen control valve on the torch handle should be fully opened so that regulation of the oxygen flow takes place using only the
oxygen control valve on the cutting attachment (see fig.3A).
5.2.2
The flow of the acetylene is still controlled by the red coded knob on the torch handle.
5.2.3
The flame is then set up using these two control valves only.
5.2.4
Once the flame is set additional oxygen can be introduced into the centre of the flame to initiate the cutting process by operating the
oxygen control lever (see fig.3B) mounted on the cutting attachment.
SGA2 & SGA6 - 4 - 09/02/06
fig.3
# IMPORTANT! LEAK TEST ALL CONNECTIONS AND VALVES PRIOR TO EACH USE OF THE EQUIPMENT.
# IMPORTANT! LEAK TEST ALL CONNECTIONS AND VALVES PRIOR TO EACH USE OF THE EQUIPMENT.
SGA2 & SGA6 - 4 - 09/02/06
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