Lincoln Electric IM703-A manual Making a TIG Weld with AN Amptrol, Smaw Process, Gtaw Process

MAKING A TIG WELD WITH AN AMPTROL

1.Install welding equipment per Section A-5.

2.Setup controls per Section B-10.

3.Turn on the shielding gas supply, and torch coolant

input supply (if used).

Note: The Precision TIG Under-Cooler (or Water Solenoid connected to the Cooler receptacle) runs with the Fan-As-Needed machine cooling fan (See Maintenance Section D), so the cooler fan and water pump will also not run continuously in idle, but will run while welding.

4.With the torch held safely away from everything, close the Arc Start Switch of the Amptrol and set the gas flow meter. Then open the switch. The welder is now ready for welding.

5.Position the tungsten electrode at the start of the weld at a 65° to 75° angle with the horizontal, in the direction of pushing travel, so that the electrode is approximately 1/8" (4 mm) above the work piece.

Close the arc start switch. This opens the gas valve to automatically purge air from the hose and torch, then shields the arc strike area. After the 0.5 sec- ond preflow time, the high frequency becomes available to strike the arc. When the arc strikes the torch coolant (if used) starts to flow. Also, if welding DC- TIG, the high frequency shuts off just after the arc strikes.

6.Hold the arc start switch closed at minimum Amptrol Start level (See Section B-10) until an arc is estab- lished, then increase the output to the desired welding level and push the torch in the direction of travel.

7.At the end of the weld, decrease the Amptrol output to the crater-fill level before releasing the arc start switch to start the Postflow time. Hold the torch gas shielding over the solidifying weld crater while post- flow time expires and the gas valve reopens. The torch coolant (if used) continues to flow for up to 8 minutes after the arc goes out (with the Fan-As- Needed feature) to assure torch cooling.

•Repeat steps 5 through 7 to make another weld.