Gas Connections; Assembling Front End Parts - ESAB PT-25 Manuel D'instruction

SECTION 3
PT-25 100 Amp
Material Thickness (mm)
Figure 3-1. PT-25 Cutting Data, Air/Air

3.4 GAS CONNECTIONS

After the gases for the job have been selected, connect the
gas supply hoses to the fittings at the back of the power
source. Note there are two fittings for each gas. Use the fit-
ting which best matches your hose. Do not use oxygen as
plasma or cooling gas for the PT-25. Do not use argon or
argon mixtures for cooling gas. Make sure that the fitting
not used for each gas is plugged with the plug attached to
the power source.

3.5 ASSEMBLING FRONT END PARTS

WARNING
Make sure power switch on power source is in the OFF
position and primary input power is deenergized. Fail-
ure to install front end parts properly can expose you
to high voltage or fire.
BE SURE:
• Electrode holder assembly is tight.
• Swirl baffle is installed and fully snapped into place.
• Electrode is installed and tight.
• Nozzle is installed.
Thread the electrode holder assembly 0558000731 (21657)
into the torch body and tighten it securely in place using
a 7/16" nut driver. Avoid overtightening and rounding off
the hex on the electrode holder assembly.
Thread the electrode onto the electrode holder and tighten
securely using the thumb and forefinger. The electrode is
tightened properly when a slight snapping action is felt
100 Amp Cutting Data
Air Plasma at 4.8 bar
Air Cooling at 4.8 bar
Carbon Steel
Aluminum
Stainless
86
PT-25 150 Amp
Material Thickness (mm)
Figure 3-2. PT-25 Cutting Data, H-35/N
as one twists the electrode to remove it. Use electrode
0558000732 (21595) for plasma gases of air, nitrogen or
nitrogen/hydrogen mixtures. Use electrode 0558000733
(21780) for argon/hydrogen (H-35) plasma gas.
Install the swirl baffle 0558001457 by pressing it onto the
torch insulator. The grooved face of the swirl baffle fits
against the torch insulator and it should snap into place
on the torch insulator.
NOTE:
Poor PT-25 plasma cutting performance will be caused by
improper baffle positioning. Due to small tolerance varia-
tions, the baffle might not seat squarely against the insulator
body when it is installed independent of the nozzle and heat
shield. This condition causes plasma gas leakage into the
shield gas causing generally poor cutting performance and
lower consumable life. To improved plasma cutting perfor-
mance assemble the consumables as shown in Figure 3-4.
Select the proper nozzle according to the cutting current
which will be used, or select the gouging nozzle for gouging
between 100 and 150 amps.
Drop the nozzle into the heat shield 0558000730 (21660)
so that the nozzle protrudes out of the shield's smaller end.
Thread the heat shield onto the torch body, tightening it
firmly by gripping it in the palm of the hand and twisting
until the nozzle is fully secure and further twisting is notice-
ably more difficult.
If the optional gouging guard 0558000737 (21656) or stand-
off guide 0558000736 (21943) is to be used, install it over
the heat shield by pushing and twisting in the clockwise
direction until it is fully seated on the shield.
INSTALLATION
150 Amp Cutting Data
H-35 Plasma at 4.8 bar
Nitrogen Cooling at 4.8 bar
Aluminum
Stainless
2