Acceptable v/s Non-Acceptable Consumable Wears: Part 2

Previously, on “Acceptable v/s non-acceptable consumable wears”, we learned about electrodes and shields. Up next on the series is the nozzle and swirl ring.

Let’s start with nozzles first.

Nozzles

The nozzle is located at the bottom of the laser head, from where the high-pressure airflow is emitted. If you talk about Hypertherm spare parts, its nozzles are carefully engineered and can withstand extreme heat. The plasma arc temperature is 25,000 degrees F, and an electrically charged arc can pass through the copper nozzle without melting it. Isn’t that amazing?

How to evaluate the wear of the nozzle?

When evaluating the wear, you need to focus on the nozzle tip where the orifice is located. When it’s new, the orifice is round with no nicks and sharply defined edges. As it wears down, the edges turn to round a bit. You may also see some metal debris or splatter at the end. Still, you can use it as long as the orifice remains round with no nicks. But if there’s any change in the shape of the orifice, you may need to examine it closely as it will impact the cut quality. A jeweler’s eye loupe or microscope can help you examine the orifice.

Along with the orifice, you also need to check the inner bore of the nozzle. If the inner bore has gray/white residue or black/gray swirl, it’s normal. The residue is hafnium oxide and can be cleaned with a pencil eraser. The swirl is the carbon tracks formed during the arc start.

What can you do?

Choose Hypertherm nozzles. They have a two-piece nozzle design to withstand the heat and last longer. The design incorporates a proprietary gas swirl technique that creates an unionized gas layer between the arc and the nozzle. It increases energy density, releases gas pressure to the atmosphere, and again increases it to four times the conventional plasma density.

Note: You can look for Hypertherm parts online too.

Next in the line is the swirl ring.

Swirl Ring

A swirl ring controls and swirls the plasma gas around the electrode into the nozzle. This helps control the arc attachment point on the electrode emitter so that gas flow delivers the best edge angularity. The plasma gas, when controlled, creates a centrifugal effect that arranges the unionized gas molecules to the orifice edge to help them last longer.

In addition, a swirl ring aligns electrode emitters with a nozzle orifice and insulates the negatively charged nozzle with a positive nozzle electrically. It helps increase the lifespan of the consumables and improve the cut quality.

When should you change the swirl ring?

If the swirl ring is cracked, replace it as even a tiny crack can impact the gas flow. Next, when the O-rings get torn, cut, or wind up with flat spots that prevent the tight seal formation.

However, with careful use and clean hands, a swirl ring can last upto 50 electrode/nozzle change-outs or more.

To inspect the swirl ring, here’s what you should do:

  • Check for cracks and chips carefully. Even a small crack will impact the flow of the gas.
  • Inspect the O-rings (especially the inside part) for torn, cut, or spots.
  • Examine the swirl holes for blockage. If there’s any grease or debris, try to clear it out. If successful, you can reuse the swirl ring. If not, replace it with one from the Hypertherm spare parts category.
  • Ensure the swirl ring is not greasy or dirty.

After inspection, if everything’s better, you can put the swirl ring back on the torch. While doing so, add the lubricant on the outside of the O-rings. It should look shiny, but there should be traces of lubricant, so rub it properly.

The lubricant will help you put the swirl ring back quickly and minimize the chances of resistance that can cause crack or chip.

Alternate Option

Look for Hypertherm parts online. Hypertherm swirl rings are made of volcano lava that is refined in a machine and then baked in the oven to increase durability. Other reasons to use volcano lava are: it has good insulating properties and can withstand a lot of heat.

The durability means that they won’t wear out. However, they are fragile. Force into a torch or dropping it can cause cracks or chips. Hence, the wise option is to look for one that fits your requirement.

Don’t forget to replace it on time as it can lead to poor cut quality.

Alright! That’s it for today.

In the next series, let’s learn about retaining caps.