ir compressor users often ask if they can use the PEX airline with their overall system because it is affordable and easy to use.

PEX offers some benefits that other kinds of lines do not and there are many reasons why you might want to use PEX for this need even if you are not worried about the price. You should know if this is a viable option for your air compressor use before you try it out, however.

PEX is not rated for compressed air and is rated as a water pipe. That being said, many people do use PEX for their air compressor lines despite the fact that the manufacturer does not recommend it for this use. PEX will hold compressed air at pressure but the product is not made for this use.

If you are still thinking that you might want to use PEX for your air compressor lines, you should read on to learn some more about this product.

What is PEX?

PEX is a polyethylene product that has undergone a chemical change in its molecular structure. The polymer chains in the PE product that are used to make PEX are cross-linked which makes them more flexible than other kinds of lines.

PEX is a cheap material that is actually intended for water lines, but many people choose to use it for their air compressor lines due to the price point and the flexible nature of this product.

PEX comes with some other benefits that other metal pipings cannot offer, which is part of why this solution to air compressor piping is so common despite the fact that the manufacturer does not recommend it for this use.

Benefits of PEX for Compressed Air

There are some clear benefits to using PEX for compressed air despite the fact that it is not really rated for this task or made with it in mind.

·Cheap

PEX products are much cheaper than the normal metal lines that are used for these kinds of purposes. Many people find that this is significantly cheaper as a product.

·Flexible

PEX can be bent and flexed readily, which makes it easy to work with and easy to install in any system that you are using it for.

·Does Not Conduct Heat and Cold

PEX is more neutral temperature-wise than other products, particularly metal.

Cons for Using PEX for Compressed Air

·Not UV Resistant

One of the biggest downsides to PEX for this use is that it cannot be exposed to UV rays. This means that it cannot be used in any application that is going to be used outdoors. The piping will harden and crack, which is less than ideal for compressed air systems.

·Prone to Cracking

Cracking is a common issue with PEX, and you should be aware that as it ages, it will likely crack. This is due to a variety of factors that are related to using this product in a manner that it was not designed for.

·Fittings Cause Issues

The biggest weak point of the PEX product in this application is that the fittings are not made for use under pressure.

It can be very hard to get a good connection that will hold the pressure of the compressed air that is in the PEX lines.

How do I Connect my PEX to my Air Compressor?

PEX is not made with the fittings that are needed for compressed air systems. This means that you will have to create your own fittings.

The quality of the work that you do here will predict the quality of the function of your lines once you have made them into air compressor lines.

This is often one of the trouble points for this kind of use of PEX, and you will need to be very sure that you are doing a great job at creating these connections or you will have nothing but problems with your PEX tubing.

Here are the steps that you will need to follow to create air compressor connections using PEX:

Buy Some metal rings for the end of the PEX tubing. There are kits that sell these rings which are sized correctly and made with the right materials to get along well with the PEX tubing itself.

  1. Fit the barbed end of the connector into the tube.
  2. Use crimpers to crimp the metal ring that is below the metal barb on your fitting that 
  3. is inserted into the PEX tubing. People often use a Shark Bite Crimper for this.
  4. For the regulator end, you will place a ring on the PEX line and then connect the tube to the regulator end.
  5. Crimp the ring just like you did with the other end of the PEX line. Turn on your compressor and make sure that you do not experience any issues with leaks or other problems.

This is not a difficult process, but you will want to have the right tools on hand and the attention to detail to make sure that you have created the connections properly. Poorly-fitted connections are often the biggest problem with using PEX in this kind of application.

What Pressure Can PEX Handle?

PEX can hold a burst pressure of up to 800 psi. This is actually two times the requirement for ASTM F876, which is the standard specification of the PEX tubing. That being said, this is a product that is made to handle water pressure and not compressed air pressure.

Many users report that as the temperature goes up, the operating pressure drops. As an example, at 73 degrees F, you will get around a 160 psi rating from this product. At 180 degrees F, you will only have access to a 100 psi rating for the PEX lines.

Being flexible and prone to cracking and stretching, PEX can sometimes have trouble holding compressed air and experience breaks or cracks due to the pressure within the PEX lines.

You might also find that the PEX line is not the trouble but that the fittings are your weak spot where compressed air is leaking out and reducing your pressure significantly.

What Are Other Solutions for Compressed Air Lines?

There are some common solutions that are used instead of PEX for compressed air. These are the kinds of lines that will be installed if a builder is creating your shop for you because they cannot use products that will not meet the minimum requirements for set tasks.

These products are often more expensive but they are also rated for this use, which can be a big advantage to choosing them over other products.

Black Pipe

This is a kind of piping that is recommended for compressed air systems. It is easy to source and is very strong and durable.

It is also rated better for UV exposure as well as extreme temperatures. This is the most common choice for industrial or shop use for compressed airlines.

This piping is actually used for gas lines as well, but it can be buried and it can be exposed to heat on the walls of your shop due to its durable nature. This is why many builders will choose it for your shop air compressor lines.

Black pipe can also produce rust contamination that can damage pneumatic tools when exposed to the wrong conditions.

Aluminum Pipe

This is another common choice for the air compressor lines in a shop or garage environment.

This is because this kind of piping will not corrode and it is resistant to leaks. It is lightweight and easy to bend as needed and install. It also provides superior connections with the air compressor fittings.

Copper Pipe

Although not as common, Type K Copper pipe can be used for all kinds of applications, including air compressor use.

It comes in both a rigid and a flexible form and is made in some instances with flared ends that are specifically for air compressor fittings.

This is a more expensive option in most areas, but you might find that sourcing can be easier for this kind of piping depending on your location.

PEX Can be Used for Your Compressed Air Needs

While this product is not made for this use, there are many people who use PEX for their air compressor lines without any issues.

Always remember that you are using a product that is not rated for this use and make sure that you are careful when you create all of the connections to your compressor. Also, make sure that you are not exposing the PEX to lots of heat and sunlight.

PEX is flexible, cheap, and easy to install in many ways, but it may not have the lifespan of some of the more common solutions that are actually rated for compressed air. Always keep this in mind when you decide to use PEX for this use.

You might find that the benefits outweigh these concerns, but they should be a part of your considerations when you are planning out your air compressor system.