Accessories and small parts for a handheld air plasma cutter, and how to choose and look after them.
What does the swirl ring do?
The swirl ring sits inside the torch head around the electrode. It has small angled holes that make the plasma gas spin as it flows. That swirling action centres the cutting arc on the electrode and through the nozzle, and helps constrict the arc for a faster, cleaner cut.
Because the holes are small, they must stay clear. Clogged swirl holes reduce cut quality and shorten the life of the electrode and nozzle. Check it each time you change consumables, and follow your manual for how it should be fitted and in what order.
How do I tell the swirl ring is worn or damaged?
Look at it whenever you change the electrode and nozzle. Check that the small holes are clear of dirt and any excess lubricant, and that the body is not cracked, chipped or heat damaged. Some swirl rings are made of ceramic and are fragile, so a drop onto the floor can chip or crack one without it being obvious.
A clean, undamaged ring normally lasts through several electrode and nozzle changes, but there is no single interval for every cutter, so follow your manual. Poor cut quality, a short life for the nozzle and electrode, or hard starting can point to a problem here, though they have other causes too.
How do I make sure consumables and parts match my torch?
Consumables are specific to the cutting current, the material and the job. Wrong ones are a common mistake, so check the part numbers in your manual against the markings on the parts you are fitting, and fit them in the order the manual shows.
Mismatched torch parts are a recognised cause of early electrode wear, and so is cutting at too high a current for the nozzle. Do not over-tighten the parts, and keep all the surfaces clean of dust and dirt. If you have lost the manual, the maker normally lets you download a copy, and the data plate tells you what your cutter is.
What are the most common mistakes that wear out parts early?
Common causes of early wear include mismatched torch parts, wrong gas flow settings, gas leaks or restrictions such as kinked or split hoses, and moisture or contamination in the air. Always use clean, dry air. Nozzles are also damaged by piercing or cutting too close to the work, piercing metal thicker than the cutter's limit, too high a current, and running the electrode past its life.
Inspect parts each time you change them and replace them on condition rather than by the clock. Keep the torch clean inside. If a lubricant is needed on the O-rings, use only the type the maker names, because petroleum-based substitutes can cause fires inside the torch.
Why wear a face shield or helmet for plasma cutting?
A plasma arc gives off intense light and ultraviolet radiation, so your eyes and face need proper protection. Use welding-type shades that cover the operator's whole face. Ordinary safety glasses or sunglasses are not suitable.
A face shield also guards against sparks and hot metal. Fit a lens in the shade your cutter's manual or your risk assessment calls for, and replace the lens if it is cracked or badly scratched. Anyone watching the cutting, such as an assistant, needs protection too.
Which shade of lens do I need for plasma cutting?
The right shade depends on the cutting current, so check your cutter's manual and your risk assessment first. Shade tables give a lighter minimum for low-current cutting and a darker one as the current rises, and a higher shade number means a darker filter. A common rule of thumb is to start with a shade that is too dark to see the cut, then go lighter until you can see well, without going below the minimum.
If you cut at different currents you may need more than one lens. An auto-darkening helmet may not suit light work if its lightest setting is fairly dark, so check its range. Never use a lens lighter than the manual or your assessment allows.