Tweco 251 Thermal Arc Fabricator - Manual (Page 48)

FABRICATOR 251
OPERATION 4-10 Manual No. 0-4847
4.05 Installing A New Wire Conduit
1. Be sure the MIG gun cable is arranged in a straight line, free from twists, when installing or removing a wire
conduit. Remove the old conduit by first removing the MIG gun nozzle, contact tip, insulator and gas diffuser.
Then loosen Allen screws in the conductor tube and connector plug and pull the old wire conduit out of the
cable assembly from the connector plug end.
2. To install a new conduit, first inspect the o-ring gas seal on the conduit for cuts or damage. Start from the
connector plug end of the assembly and begin pushing the conduit through the connector plug, cable assem-
bly and into the gun. If the conduit should lodge along the way, gently whip or work the cable assembly to aid
forward movement.
When the conduit stop meets the end of the connector plug and the new raw end extends through the end of
the conductor tube on the welding gun, tighten the Allen screw in the connector plug onto the conduit to
prevent its backward movement.
CONDUCTOR TUBE
CONDUIT LINER
CONDUIT LINER
1 1/16"
(27mm)
Art # A-08236
REMOVE
CONSUMABLES
ALLEN SCREW
O-RINGS
ALLEN SCREW
CONNECTOR PLUG
Figure 4-14: Conduit Trim Length
NOTE
When the conduit is fully inserted into the cable assembly and the conduit stop is firmly against the
Connector Plug, the “raw end” of the conduit will protrude out of the open end of the gun conductor tube.
Trim the conduit as shown in Figure 4-14. The trimmed end which seats in the Gas Diffuser must be filed
and reamed smooth on the inside and outside radii so wire feed will not be obstructed.
3. Replace Gas Diffuser, Contact Tip, Insulator and Nozzle.
4. Tighten the Allen screw in the conductor tube.
CAUTION
Do not over tighten the conductor tube screw as this action will result in the distortion of the conduit and
will lead to wire feedability problems.