PEX pipe has become popular due to its ease of installation, flexibility, and durability. PEX pipes can be installed in any direction and they can also be bent at different angles without damaging them. The design of the PEX pipe allows it to withstand high temperatures up to 200°F (93°C) with very little pressure loss.
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.
The main advantage of using PEX pipe for compressed air lines is that it has a long life expectancy when compared to copper pipes or other types of plastic pipes. It also has excellent corrosion resistance and since PEX pipe is non-toxic, it does not emit any harmful gasses when heated or bursts open during pressure testing.
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.
Why Use PEX Pipes For Compressed Air?
PEX is made of cross-linked polyethylene which is more resistant to stress cracking than copper or CPVC pipe. It will not corrode, scale or rust like metal pipes do. PEX is easy to install, cut, and repair and it can be reconnected by using a coupling or crimping tool.
Here are a few benefits that come with using PEX pipes for compressed air:
- Affordable solution for compressed air lines: PEX is significantly cheaper than traditional metal piping systems. This makes it ideal for building owners who want an affordable option without sacrificing performance or quality.
- Resilient against temperature differences: Unlike metal tubing, PEX expands and contracts with temperature changes — which means less risk of damage due to excessive heat or cold.
- Lightweight and flexible: PEX tubing weighs less than other types of piping, making installation easier and faster while reducing the risk of worker injury from lifting heavy materials during installation.
- Easy to install: PEX pipe installations require no special tools or skills — simply cut the material according to your needs and connect it using couplings or connectors (which come with most kits).
The DON’Ts of using PEX pipe
The use of PEX pipes in compressed air lines requires care and precautions to ensure that it is safe to use. The following points should be kept in mind while using PEX piping for a compressed air line:
1) Do not bend or flex the pipes while they are under pressure. This may cause them to rupture or burst open.
2) Never use any other material along with PEX pipe in a compressed air line because it will increase the chances of leakage from the joint areas and cause serious problems in this case too.
3) Keep the joints tight at all times as any leakage from these areas may cause damage to equipment or even cause personal injury due to lack of oxygen.
4) PEX is easily damaged by UV rays and UV light. This is the main reason why applying it in outdoor areas is not the best idea. The best places to install PEX pipes are indoors, preferably in dry and dim areas of the property. You can also install it inside the walls.
5) PEX requires more fittings than copper or polybutylene because it does not expand like these other two materials and therefore cannot be bent into place like them either. Bending extensively may cause cracking.
Because of this, you need to plan out your layout carefully before installing your new PEX piping system or you may end up wasting time and money by having to rip out sections of pipe just because they do not fit together properly or do not allow enough room for expansion or contraction over time due to temperature changes.
Pros/Cons of using PEX pipe for compressed air
The material used to make PEX pipes is also called cross-linked polyethylene. This means that the chemical bonds between the molecules have been altered so they form multiple bonds between each other, instead of just one single bond like regular polyethylene pipes do.
Here are the pros and cons of using PEX piping:
Keep in mind: The advantages listed below outweigh the disadvantages when the pipings are used indoors or inside walls. If you plan to use the pipings outdoors, then the disadvantages outweigh the advantages.
Pros of using PEX piping
- Inexpensive
- Highly flexible
- Easy to set up
- Heat resistant
- Durable when kept in dry areas such as indoors
Cons of using PEX piping
- Non-durable when exposed to UV rays
- Non-durable when exposed to moist areas
- Unrecyclable
- Bad performance when used outdoors
Types of PEX pipes For Compressed Air
PEX pipes come in different sizes and shapes. These include tubes, elbows, couplings, tees, valves, etc. The pipe comes in two forms: rigid and flexible. The rigid form can be installed by itself without the need for fittings as it simply fits over the cut pipe ends with no additional connectors needed.
The flexible form of PEX pipe requires fittings like elbows or tees to connect multiple pieces at various angles or turns which may vary from one project to another depending on where the fitting goes on each end of the pipe length joined together by the fitting itself.
PEX tubing
This is tubing that is made of cross-linked polyethylene. It can be a good replacement for copper or steel pipes. This material is flexible, durable, and easy to install. The PEX tubing comes in different shapes and sizes, which can be used for various applications. It is available in coils or flat sheets that are used for plumbing purposes.
PEX pipe
PEX pipe is also made from cross-linked polyethylene and offers great resistance to corrosion and chemicals, making it a better solution for outdoor use than the rest of the mentioned types of PEX pipes. This is due to being slightly easier to repair and replace due to damage caused by extreme weather conditions like high pressure or temperature variations.
Uponor PEX
Uponor is a type of plastic tubing that has been reinforced with reinforcement fibers. The reinforcement fibers give it extra strength and durability. The main advantage of using Uponor PEX is that it can withstand high pressure.
Another advantage of using this type of pipe is that it has an excellent resistance to abrasion, which means that it can be used in applications where there are a lot of vibrations or movements.
Viega PEX
Viega PEX pipes are available in different dimensions, such as 16 mm, 20 mm, and 25 mm. The pipe can be installed in just about any location and is easy to handle during installation due to its flexibility. It can easily be used for compressed air lines. This type of PEX pipe also has a good pressure rating.
What is The PSI Rating For PEX pipe?
PEX tubing has an extremely high tolerance to pressure differentials between systems with working pressures up to 160 psi (1034 kPa). PEX tubing can carry high pressure.
The psi rating for the PEX tubing is the maximum pressure that can be safely applied to the pipe without damaging it. The psi rating of a pipe is determined by its material and design. The psi rating for PEX tubing is determined by two main factors, including:
Working Pressure – This refers to the maximum amount of pressure that can be safely applied to a pipe without damaging it. The working pressure of any pipe will depend on its material and design.
Diameter – The diameter of a pipe also determines how much pressure it can withstand before bursting or leaking. The larger the diameter, the higher the maximum allowable pressure will be.
Does PEX hold air pressure?
The answer is yes, PEX can hold air pressure. It depends on the ASTM F876 law. The ASTM F876 law states that the maximum working pressure for PEX piping is 800 PSI and for rigid PEX piping it is 600 PSI.
PEX can hold up to twice the working pressure compared to what this law states. This means that PEX can hold around 1,400 PSI and around 800 PSI for rigid PEX piping systems respectively.
The capacity of PEX to hold air pressure will depend on several factors such as the age of the pipe. The older your pipes are, the more they lose their ability to hold air pressure.
This is because they have been used more often than new ones and they have been exposed to many elements that cause wear and tear over time. If you have an old pipe in your house, then it will not be able to hold as much pressure as a new one would be able to do so.
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.
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.
- Fit the barbed end of the connector into the tube.
- Use crimpers to crimp the metal ring that is below the metal barb on your fitting that
- is inserted into the PEX tubing. People often use a Shark Bite Crimper for this.
- For the regulator end, you will place a ring on the PEX line and then connect the tube to the regulator end.
- 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.
Summary
PEX pipe for compressed air has a relatively low cost on average. It is so versatile that it will work in nearly any application you have! One of its greatest aspects is that it is flexible and can be used above and below ground. PEX pipes can withstand cold temperatures, high sulfur contents, or even a broad range of chemicals.
PEX pipe for compressed air is also easy to install, making it beneficial for commercial purposes as well. It has many uses in air compressor systems which is why the use of PEX pipe in compressed air systems is growing at such a rapid pace.