If you’re running a plasma cutter in your shop chances are you have considered getting an air dryer to place on your air compressor. An air dryer is a great way to reduce the amount of moisture, oil and particulates that are often times fed through your air line by your compressor into your plasma cutter. They can be filtered out by an external filter that is placed between your compressor and plasma cutter. This filter is serviceable and can be maintained by changing the filter cartridge inside of the filter housing after a extended period of use.

What are the benefits of using an air dryer with a plasma cutter?

Using an air dryer to provide filtered air to your plasma cutter will help increase the life span of your torch consumables and allow you to make cleaner cuts. If your air is dirty your consumables will deteriorate faster and your cuts will suffer. Most plasma cutter owners that use their machine often find that running an air dryer filter saves them money in the long run from the reduced amount of consumables they have to purchase. Running an air dryer filter will also reduce the amount of time you have to spend replacing consumables while on the job.

The following video below is by Jim Colt who is a member of Hypertherm’s team. He has spent much of his time on forum sites helping members of the plasma cutter community by answering all of their commonly asked questions. He is a very knowledgeable source of information and in this video he addresses the effects of moisture, oil and particulates in a plasma system.


Motor Guard M-30 NPT Submicronic Compressed Air Filter

The Motor Guard is a common inexpensive filter that is used and recommended by a lot of different plasma cutter owners. It’s well known on many forums as the “go to” filter for plasma cutters as it’s simple to install and easy to maintain. It houses one single replacement cartridge that traps moisture, oil and particulates from going into your air supply line. This filter cartridge needs to be replaced after extended use. With Motor Guard being so popular you can be confident that replacement filters will be available many years from now.

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Motor Guard M-723 Replacement Filter

Replacement filter for the Motor Guard listed above. Very easy to change and only runs about $20.

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How can I tell if I have moisture in my air and my filter needs to be replaced?

One method of testing your air for moisture can be seen in this video here by Jim Colt from Hypertherm. In the video he explains that you can use an air nozzle to blow air on a small mirror and if the mirror starts to collect moisture then it’s time for a filter change.

Not All Tools Need Filtered Air

Not every tool in your shop needs filtered air. That is why it is important to have sources of filtered and non-filtered air in your shop. This will help reduce the amount of filter cartridges that you use. If you’re filling a tire on your truck with air you don’t want to be running that air through your cartridge as it’s just a waste. The easiest way to do this is by mounting your air filter directly to your plasma cart and only using it with your plasma cutter. This is the method I prefer to use. If you have a variety of tools that need filtered air like a paint sprayer then you can simply split the air output right at the compressor and install the filter on one side only. That way you can hook to your filter when needed. If I am using this method I like to also install a cut off valve before the filter just to make sure it only sees air when I am using it.

Filtered Air For Large Scale Plasma Systems or Professional Use

Ingersoll-Rand Refrigerated Dryer (IRR-D42IN)

If you work in a shop that uses a plasma cutter for large scale projects and production then it will be beneficial for you to invest in a refrigerated air dryer. This is a machine that will completely eliminate moisture from your system and do so all day long without maintenance. This works especially great for CNC plasma cutting systems that see long periods of use without interruption, however it can be used on other tools as well.

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Additional Resources

If you have never used a plasma cutter before be sure to read our comprehensive beginner’s plasma cutting guide. This will help walk you through the entire process of getting your machine hooked up correctly and making cuts safely.

If you are looking for help finding a new machine be sure to check out our list of the best plasma cutters that we recommend. If you need a plasma cutter with a built in air compressor you can view the machines that we recommend here.