Types of PEX.
All PEX pipe is divided into 3 main types:
A, B and C
The types of PEX pipe A, B, or C type are not separated by grade. The letters identify the manufacturing process and have nothing to do with quality of performance ratings.
Surprising PEX facts:
1. PEX-B can withhold higher pressure than PEX-A.
2. PEX-B performs 30-40% better in chlorine testing than PEX-A and PEX-C.
3. All types of PEX have to comply with ASTM F876 and ASTM F877 standards.
PEX-A tubing is produced using Peroxide method.
PEX-B is made using a “Silane” or “Moisture Cure” method of cross-linking, where links between the molecules of the HDPE form after the extrusion process using a catalyst and exposing PEX tubing to water.
PEX-B is the most common and is manufactured by a large number of companies, such as: Viega, Watts, Bow, Everhot, Zurn and many others.
PEX-C is manufactured using “Electronic Irradiation” method of cross-linking, also known as “Cold” cross-linking. Here, cross-linking of the molecules is done after the process of extrusion by exposing the pipe to an electron radiation beam.
Some PEX-B manufacturers are: Nibco, Roth, Cash-Acme.
Which PEX tubing to choose?
That depends on many factors, such as your budget, skill level and whether you have already bought any tools or materials.
PEX-A is the most expensive of all 3 types and each manufacturer typically requires using their own proprietary connection system. Because of that, tools and PEX fittings can also be very costly.
Other than slightly greater flexibility than of the other (2) types, there are no significant advantages of this type over the other two. If fact, it has been reported by many contractors that the expansion connection system used with PEX-a may be very inconvenient to use in colder climates.
PEX-B is the most typical and the most affordable type of PEX tubing in the US. You will find it being sold by local plumbing and heating retailers, as well as the big box stores such as Home Depot or Lowes. Due to an extensive performance history and compatibility with a large number of connection systems, PEX-B is very popular both among DIY’s and professional contractors.
PEX-C is the latest addition to PEX line and price-wise is similar to PEX-B tubing. Unfortunately, the cross-linking process for this type creates the least amount of bonds (vs. the other types), which makes it closer to a regular PE (PolyEthylene, or, simply plastic) pipe rather than true PEX tubing. Similar to PEX-B, this type can be used with a large variety of installation methods.
What are the different types of PEX pipe?
Thanks for this information.I heard about pex repiping process little bit was not having any idea that pex repipe is of three types process.thank a lot.
ReplyDeletepex repipe orange county