Identifying Damaged Consumables in a Plasma Cutting System: Part 2

Contact Tip Welding

In the first part of this two part series we took a look at how you can be proactive and identify consumables of your plasma cutting machine that are beginning to give way. We specifically took a look at the outer retaining cap, inner retaining cap and shield cap. In this second part, we’ll take a look at more consumables and how you can identify damage to the consumables which could hamper the functioning and efficiency of your plasma cutting machine.

The Nozzle

The nozzle that is usually made of copper directs the plasma arc through a small aperture of varying diameter. This orifice is in a perfectly rounded shape and has a sharp, defined edge when the nozzle is new. This is the most critical part of the plasma torch which results in precise and top cut quality.

When the aperture begins to go out of shape in the inner or outer bore, the nozzle must be replaced. Sometimes, you may find some light swirl marks on the inside surface of the nozzle. This is caused by the arc starting and does not warrant a nozzle replacement.

The Swirl Ring

This is usually manufactured with a material that is resistant to high temperature such as ceramic or Vespel. Hence, the swirl ring is not eroded by the plasma arc. The swirl ring insulates the nozzle and the electrode and also serves as a means to cause the swirling of the plasma gas, which is required to make precise and accurate cuts.

You must take care that the tiny holes in the swirl ring remain clean and free from any dirt or debris. If there is any cracking or chipping in the swirl ring, it must be replaced.

The Electrode

This is usually manufactured using copper or silver or a mix of both metals. It contains an emitter rod insert that is made of tungsten or hafnium. This emitter rod stops the electrode from burning when exposed to the high current arc.

The emitter rod is consumed for the entire duration that the plasma torch is switched on. Ultimately, it will reach a point where the plasma arc will jump to the electrode directly. This can cause a blowout and can also damage the shield cap, nozzle and eventually the head of the torch too.

Consumables play a very important role in the life and performance of a plasma cutting system. Every component plays a very vital role in producing the highest quality, precision cuts. Therefore, constant inspection, monitoring and replacement of consumables is very critical to the maintenance of your plasma cutter.

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