ESAB PT-20AMX Manuel D'instruction page 279

SECTION 5 MAINTENANCE
3. Remove the nozzle and electrode assembly and inspect for wear. The nozzle orifice
should be round at both the entrance and the exit. If the nozzle orifice is worn in an
oval shape or shows other signs of damage at either end, it should be replaced. The
inside of the nozzle may have light gray deposits from the electrode. These may be
removed with steel wool but care must be taken to remove all traces of the steel
wool afterward.
If the electrode has a pit which is more than 1.5mm (0.06") deep at its center, replace
it. This is done by unscrewing the electrode from the electrode holder. Grasp the
electrode holder with the fingers using the two flats and grasp the electrode between
the thumb and finger of the other hand and twist.Inspect electrode insulator and
electrode holder assembly for signs of damage such as arc tracking or cracking and
1.5mm
replace them if any are found. Insure that the baffle tube is securely threaded into
1,5 mm
(0.06")
the electrode holder, but do not overtighten. Use the small hex end of the plastic
wrench in the spare parts kit.After installing the electrode insulator onto the electrode
holder assembly, install electrode by reversing the procedure used to remove it. Note
that firm tightening of the electrode by hand is sufficient, the use of tools such as
wrenches or pliers is not required or recommended.
4. Inspect heat shield for signs of damage or wear. The gas holes inside shield should
not be blocked by debris, and there should be no signs of arcing anywhere inside
the shield. The outer insulating jacket of the shield should not be severely charred
or eroded. Replace the heat shield if any of the above damage is found.
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