Plasma technical tip: How to properly maintain the O-rings in your plasma torch

By Ann Thompson, Hypertherm
Posted on 01/22/2019 in SPARK the blog, Plasma cutting

Due to their small size, low cost, and straightforward design, the vital function of an O-ring is frequently overlooked and regular maintenance checks are often ignored, but operators can avoid serious downtime by getting into the daily habit of properly maintaining the O-rings on their consumables and in the plasma torch.

Two key factors are critical, the silicone application and O-ring condition. Damaged, worn, dirty, dry, or over-lubricated O-rings can cause unwanted disruptions to production. Here are some common signs of O-ring trouble.

• The torch assembly is tight fitting and does not glide together easily
• Gas blockage or inconsistent gas flow
• Coolant is leaking from the torch
Cut quality is prematurely diminished
• Your consumable life is shorter than normal

O-rings need to be replaced anytime there is visible wear or damage. If an O-ring is cracked, then it needs to be replaced. This applies not only to HyPerformance systems, but to air and conventional plasma systems as well. Check to make sure the O-rings on your consumable parts are securely situated and have not rolled out of place. If you have a HyPerformance system or conventional plasma (with the exception of the original torch found on our older MAX200 systems) you also need to inspect, and if necessary replace, the O-rings found on the bullet plugs inside the torch. We recommend routine visual inspections to determine replacement frequency.


When re-installing or replacing the O-rings, you may find it helpful to use a silicone lubricant. Put a small amount on your index finger and then rub it together with your thumb, as shown in the photos on the opposite page. Now apply the thin film to all the torch and consumable O-rings. You only want to give the O-ring a “wet” look. If you can see a physical build-up of silicone left behind, you have applied too much. Silicone can clog or plug ports and for that reason you need to be especially careful with its application around the swirl-ring so that the gas flow will work properly.

Hypertherm does offer silicone lubricant, part number 027055, through its network of authorized distributors. At around $7 a tube, the lubricant is affordable and should last for months. In addition, a tube is included in our preventative maintenance, torch rebuild, and starter kits. Hypertherm’s silicone is specifically formulated to condition and maintain consumable O-rings. Hypertherm does not recommend the use of substitutes, like petroleum based lubricants, as they can lead to burning or spark fires within the torch.

Questions about this tip? Hypertherm’s North American Technical Service Team is happy to help. Contact the team via email at or by phone, if you’re in the U.S. or Canada, at 800-643-9878.



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