Cross-linked polyethylene molecular chains (PEX) are formed into plastic tubing that can be used to solve a variety of plumbing and heating problems. Since its invention in the 1960’s, PEX has been widely used in Europe. In the past 10 to 15 years, it has become increasingly popular in the United States. The material has been touted as more flexible, less expensive, and better at withstanding extreme temperature than copper or CPVC pipe. PEX pipe can withstand temperatures as high as just below boiling (200 degrees Fahrenheit, 12 degrees less than boiling) and as low as just before freezing. PEX-a is the most flexible type of PEX and is able to expand in freezing temperatures and then return back to form, whereas copper pipe will burst, causing huge problems in your system.

Three grades of PEX tubing are manufactured, each made through a different production process. PEX-a, made with the Engel method, is known to be the strongest and most flexible of the three grades. PEX-b, made with the Silane method, is also relatively strong and flexible. PEX-c, made by the electronic beam method, is a more brittle material, making it more difficult to work with. Regardless of what grade you choose, there are PEX products such as tube cutters and PEX uncoilers that make the material easier to manage during installation.

Important details to know when buying PEX tubing:

1. Will you be using the tubing for a plumbing or heating application?
2. What size tubing will you need? The available sizes typically range from 5/16″ to 4″. Some applications require specific sizes; for example, only Quik Trak can only be installed with 5/16″ tubing.
3. Do you want to color code your plumbing system for easy reference? Red, white and blue tubing are available for this purpose. There is no difference in the functionality, but red is typically used for hot lines and blue for cold.
4. What length of tubing will you need? Tubing can typically be purchased in coils of 50-1200 ft. The amount of tubing needed will depend on the size of the area you are installing and the loop lengths.
5. What grade of PEX material will you need? PEX tubing comes in three material grades PEX-a, PEX-b, and PEX-c as mentioned above. If you are in a region that gets very cold, you should use PEX-a to prevent the risk of your pipes bursting in case the pipes freeze. You will also need to use PEX-a if you choose the ProPEX Expander system because only PEX-a is flexible enough to return to form and create a secure fitting after being expanded.
6. What tubing type is needed for your specific application? The three tubing types are oxygen barrier, non-oxygen barrier, and aluminum PEX. Oxygen barrier tubing is typically used for heating applications, and helps to prevent iron components, such as cast iron pumps, from rusting. The main benefit Aluminum PEX, or PEX-AL-PEX, is that it holds its shape when bent. PEX-AL-PEX is typically used for high-temperature applications, such as baseboard.

When working on a PEX project, whether it is for a heating or plumbing system, you will need a variety of products in addition to PEX tubing. PEX fittings (specialized parts designed for connecting PEX to PEX or PEX to copper) and PEX tools (tools designed specifically to work with PEX products) will be crucial to the success of your heating or plumbing project. You will also need a PEX radiant heat manifold or PEX plumbing manifold as well as insulation, thermostats other installation parts. controls such as thermostats, and heat insulation could also be purchased. Radiant heat and PEX plumbing starter packages can also be found online to make it easy for DIYers to get everything they need for their project in one place.

Plumbing and heating problems have been solved using PEX products for decades. These products are made with a polymer material that is flexible, less expensive and better able to sustain extreme temperatures than copper or CPVC pipe. There are many choices to consider when planning your project and it is important to choose parts that are compatible with all the other parts you have chosen and with your system. Consider PEX tubing and PEX products for your next heating or plumbing job.