Operation - ESAB PT-25 Manuel D'instruction

SECTION 4

4.1 OPERATION

CAUTION
Wear the usual protective gloves, clothing, ear protec-
tion and helmet. Read Safety Precautions covered in the
instruction manual packed with your power source.
The torch is now ready for cutting or gouging operation.
Refer to the instructions for your power source for making
any control adjustments.
WARNING
Never touch any parts forward of the torch handle
(nozzle, heat shield, electrode, etc.) unless the power
switch on the power source is in the OFF position.
1. Turn the gas test or gas mode switch to the test or set-
up position.
2. Turn the power switch to the ON position. Gas should
now flow through the torch.
3. Adjust the gas pressure settings at the gas supply regu-
lators to the values given in the operating parameters
section. Turn the gas test or gas mode switch to the op-
erating position. Gas flow should now stop. Adjust the
current control to the correct setting for the nozzle.
4. Bring the torch into the proper position for cutting
or gouging. For cutting, the torch stand-off (nozzle-
to-work distance) should be approximately 6mm. If
possible, start the cut from an edge on the workpiece.
If piercing must be done, tilt the torch at an angle to
deflect the molten metal away from the torch and
operator until the pierce is complete, then bring the
torch back to 5° to 10° from the vertical and begin the
cut. For gouging, place the torch over the work at an
angle of 35° to 45° from the horizontal.
5. Lower your protective helmet.
6. Push down and hold the torch switch button. The gas
should start flowing. Two seconds later, the main con-
tactor should close and the arc should transfer to the
workpiece.
NOTE: Your power source may allow the preflow time to
be extended longer than two seconds, usually up
to four or five seconds. If, at the end of the preflow
time, the pilot arc does not ignite, release the torch
switch and check the gas pressure settings. If the
pilot arc does ignite but does not transfer to the
work, release the torch switch and check to see
that the torch is in the proper distance from the
work and that the work clamp is firmly connected
to the work piece.
7. When cutting, maintain the torch stand-off at a distance
of between 5mm and 13mm. When cutting thinner
plates, the stand-off should be closer to the lower end
of the range and it should be closer to the upper end
of the range for thicker plates. Maintain a cutting speed
which gives a cut of the desired quality and produces
a stream of molten metal emitting from the bottom of
the workpiece.
8. When gouging, maintain an angle and speed which
causes the desired amount of metal to be removed on
each pass. Maintain the torch angle so that all the mol-
ten metal is blown directly away from the torch, along
the top surface of the plate or down the groove of the
previous pass. Gouging at too steep of an angle will
cause molten metal to fly directly back at the torch.
9. If the main arc is lost during the cut (or gouge), the pilot
arc will immediately reignite as long as the torch switch
is depressed. At this time the torch should quickly be
repositioned at the workpiece to re-establish the main
arc or else the torch switch should be released.
10. The main arc will automatically extinguish at the end of
the cut as the torch is moved away from the workpiece.
The torch switch should be released immediately to
keep the pilot arc from reigniting.
11. When cutting (or gouging) operations are completed,
wait a few minutes before placing the power switch on
the power source in the OFF position to allow the fan
to remove heat from the unit. After this time, shut off
the primary power at the main disconnect switch.
89
OPERATION