Westweld FLG-200HD, Manual Instruction

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The piercing delay time should be long enough to pierce the material, but cannot be too long,
if delay time too long the arc can’t find the edge of the hole. The piercing time can be little
lengthen along with the consumables consume. The piercing delay time in the cutting chart
is based on the average piercing delay time in consumables working life.
Use“piercing finish signal” can keep high shield gas preflow pressure to protect the
consumables.
For some special process, when piercing work-piece close to the max. Piercing thickness
capacity of plasma, need consider the following important factors:
① The leading distance should be same with the material thickness, means 20mm material
need 20mm leading distance;
② To avoid the slag damage the shield cap, need to clean the slag molten pool before put
down the torch to cutting height;
③ Different material may affect the piercing capacity, especially the high strength steel,
and steels with high Mn or Gi element, the max.piercing capacity should be reduced
accordingly;
④ If it’s difficult to pierce some material or some thickness, increase the shield gas preflow
pressure can help (need to use piercing finish signal). But the disadvantage is that the arc
strike success rate will be lower;
⑤ Adopt “fly piercing” (without leading) may increase the piercing capacity under some
situation. But this process may cause damages of the torch or other parts, so stable cutting
or edge cutting is more suggested;