Tweco A120 CutMaster - Manual (Page 116)

CUTMASTER A120
SERVICE Manual 0-4989 5T-2
5T.02 Inspection and Replacement of
Consumable Torch Parts
WARNING
Disconnect primary power to the system before
disassembling the torch or torch leads.
DO NOT touch any internal torch parts while the AC
indicator light of the Power Supply is ON.
Remove the consumable torch parts as follows:
NOTE
The shield cup holds the tip and starter cartridge
in place. Position the torch with the shield cup
facing upward to prevent these parts from falling
out when the cup is removed.
1. Unscrew and remove the shield cup from the torch.
NOTE
Slag built up on the shield cup that cannot be re-
moved may effect the performance of the system.
2. Inspect the cup for damage. Wipe it clean or replace
if damaged.
Art # A-08067
Shield Cups
3. On torches with a shield cup body and a shield cap or
deflector, ensure that the cap or deflector is threaded
snugly against the shield cup body. In shielded drag
cutting operations (only), there may be an O-ring
between the shield cup body and drag shield cap. Do
not lubricate the O-ring.
Drag Shield Cap
Shield
Cup Body
O-Ring No. 8-3488
Art # A-03878
4. Remove the tip. Check for excessive wear (indicated
by an elongated or oversized orifice). Clean or replace
the tip if necessary.
Good Tip Worn Tip
A-03406
Example of Tip Wear
5. Remove the starter cartridge. Check for excessive wear,
plugged gas holes, or discoloration. Check the lower
end fitting for free motion. Replace if necessary.
Art # A-08064_AC
Spring-Loaded
Lower End Fitting
Full Compression
Spring-Loaded
Lower End Fitting at Reset /
Full Extension
6. Pull the Electrode straight out of the Torch Head. Check
the face of the electrode for excessive wear. Refer to
the following figure.
Worn Electrode
New Electrode
Art # A-03284
Electrode Wear
7 . Reinstall the Electrode by pushing it straight into the
torch head until it clicks.
8 . Reinstall the desired starter cartridge and tip into the
torch head.
9. Hand tighten the shield cup until it is seated on the
torch head. If resistance is felt when installing the cup,
check the threads before proceeding.
This completes the parts replacement procedures.