1. When dismantling a torch, be careful not to apply too much force. Prior to unscrewing the lower gland, the remaining powder inside shall be blown off with compressed air. The torch shall be dismantled by hand, without using tools such as pipe wrenches. If the lower gland cannot be unscrewed by hand, the torch shall be covered with an open-end copper sleeve whose inside diameter is the same as the gland’s outside diameter, then this assembly shall be clamped on a three-jaw chuck and loosened carefully until the lower gland is removed by hand.
2. Prior to assembling, make sure that the O-ring position on the nozzle is free of adhered powder, so as to avoid damage to the O-ring. When replacing the lower gland, it is only necessary to tighten it by hand, with no help from a pipe wrench. Try to fit the inner wall conic face of the lower gland on the conic face of the nozzle evenly and tightly, to make sure the nozzle O-ring has been applied with an even force. After having assembled the welding torch, press the water inlet on the cathode rod with a finger, and suck on the water inlet on the anode water-electricity connector with the mouth to check whether the sealing is proper or not. Normally, the mouth should not feel any negative pressure change inside the welding torch for three minutes. Otherwise, re-check all O-rings for proper sealing.
3. After having checked and found no wrong items, connect the welding torch to the water-cooled cable, and make sure that the electrodes of the water-cooled cable are connected to corresponding electrodes of the water-electricity connector. They must be connected correctly; otherwise there will be burning damage to the tungsten electrode. After having water run for 5 minutes, connect the welding torch to the ionic gas and powder feeding gas respectively, press the nozzle channel with a finger then release, and check for any leakage of corresponding channels by confirming whether there are any water drops spraying out from the ionic gas channel or powder feeding channel. Then, check that the high frequency sparks are normal. Each high frequency discharge should not last for more than 2~3 seconds, and the interval should be within 2~3 minutes. Normally, the high frequency sparks should fill 2/3 of the nozzle channel circumference.
4. Establish a non-transferred arc manually, and set the arc current at 40-60A. Observe whether the arc flame is steady.
5. After having established the non-transferred arc, press the POWDER button to see whether the powder is fed smoothly or not. In case of powder blockage, check for any gas leakage on the powder feeder.
6. If everything is normal, establish a transferred arc. When running normally, at a current of 30~60A, the non-transferred arc is able to ignite the transferred arc. If at this current, it is difficult to establish a non-transferred arc, or the arc flame cannot be blown out of the nozzle after the non-transferred arc has been established, and also the transferred arc cannot be ignited in a short moment, in this case, it is necessary to clean the inner wall of the nozzle channel and polish the tungsten electrode tip with sandpaper. When igniting the transferred arc, it is better to control the non-transferred arc at a current no greater than 80 A, or else, the cathode head must be polished. During the welding, pay attention to whether the transferred arc voltage and current are within normal ranges.