Plasma Cutting Consumables: What, Why, and How Long Do They Last?
Plasma cutters contain a number of consumable parts, which is unsurprising when you consider the very high temperatures involved in producing and focussing an arc of plasma. Keeping on top of the condition of these consumables is very important as it will help to ensure a consistent high-quality cut, and reduce the time involved in processing and refining your finished parts.
What Are Plasma Cutter Consumables?
Plasma cutter consumables are a set of components in your plasma cutter that gradually wear over time until they need to be replaced: they have a life cycle. The consumables are all found in the cutting torch itself, which is where most of the energy is focussed, and keeping track of wear and tear is a key part of maintaining an efficient machine that cuts well and lasts a long time. Plasma cutting torch consumables include: a swirl ring, electrode, nozzle, retaining cap, and shield cap.
This is a small component inside the torch that swirls the gas surrounding the plasma arc. This outer layer of gas helps to focus and direct the arc for greater cutting precision, and swirling it helps to keep it cool. As it is this protective layer of gas surrounding the arc that makes contact with the nozzle, the lower temperatures prevent the nozzle from burning up, and slow down degradation.
The electrode is a narrow piece of copper containing hafnium (which is an excellent conductor of electricity). Its job is to receive the electrical current from a cathode block inside the torch to which it is connected, and to focus the charge through its tip, which causes it to arc onto the workpiece.
The nozzle focuses the plasma arc and the gas that surrounds it to make a clean and precise cut. A nozzle with a larger opening is used for gouging, while a nozzle with a smaller opening is better able to direct the gas and so is used for fine, detailed work.
The retaining cap essentially holds all of the consumable parts of the torch together. As temperatures at this end of the machine are extremely high, it’s not just the parts creating and focussing the arc that are worn down; the component holding them together also degrades over time.
The shield is there to protect the torch and its other components from the sparks and molten metal that result from the plasma cutting process. It takes the brunt of the fallout so that wear to other components is minimised as much as possible.
How Long Do Plasma Cutter Consumables Last?
Now that we’ve looked at the role each of these consumable parts play, we’ll move on to discuss how long these elements last. The nozzle and the electrode will wear out more quickly than other components, as they are most directly involved with the creation and focussing of the cutting arc. You’ll notice nozzle wear primarily in the quality of the cut you are achieving. As the nozzle wears, the hole in the tip gets larger, which makes the plasma arc thicker and produces a wider cut (kerf) in your workpiece. You will be able to see with a simple visual inspection when the hole in the nozzle becomes too large and needs replacing.
Replacing Electrodes and Nozzles
As the electrode produces the arc, the hafnium insert melts and over time fragments are shot out through the torch in the cutting process, resulting in the development of a pit
It’s hard to be specific about exactly when you’ll need to replace your nozzle and electrode, as this will depend on many factors, including the speed you cut, the thickness of the workpiece and the amount of amperage you use. However, it is a good idea to replace your nozzle and electrode at the same time (according to whichever wears out first), as this will put you back to optimum cutting performance, rather than using a new electrode with a worn and inconsistent nozzle, for example.
Your other components won’t need replacing so
Replacing your consumables at the right time is essential for the maintenance of your machine and the accuracy of your cut. And you can rest assured that here at Esprit Automation, our partnership with Hypertherm means we can supply you with genuine plasma consumables of the highest quality.
3 tips To Prolong the life of plasma cutter consumables
1. Cutting parameters: Cutting too quickly, too slowly or at the wrong distance from your workpiece will wear your parts more quickly.
2. Correct installation: Installing your components carefully and correctly is essential if they are to function properly. This includes making sure the tolerances of the consumables match the amperage you’ll be using, as well as correct assembly.
3. Monitoring: Keeping track of how your components are wearing will enable to you prevent one worn component prematurely degrading others. You’ll need to change your nozzle and electrode more frequently than your other parts, and leaving them too long will put added strain on the whole system, as well as reduce your cut quality.
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