If you walk the plumbing aisle at your local home improvement store, you’ll likely see rolls of blue and red PEX water pipe. These flexible plastic pipes are replacing traditional copper and galvanized steel in new construction and remodeling projects.
The “X” in PEX stands for cross-linking, which is a process that forces polyethylene molecules to physically and chemically connect to each other. This changes the molecular structure of the pipe, which increases its ability to resist high temperatures and pressures.
Different manufacturers use slightly different methods of manufacturing PEX, so you’ll find that the tubing has different characteristics. For example, some may have a lower bending radius (6 times the OD vs. 8 times for PEX-B and C). But, if you’re looking for the most flexible option, go with PEX-A (manufactured using peroxide). It’s also the strongest and most resistant to cracking due to freezing. It’s a little more expensive than B and C, however.
All three types of PEX are rated for resistance to chlorine, which affects how fast the tubing will deteriorate. They are also rated for pressure and the temperature they can handle.
Rodents like to chew on PEX pipes, which is why it’s important to install them in rodent-resistant areas and to insulate them well if they are installed outdoors. This is especially true if you live in an area that gets cold weather. The rodents will chew the pipes in an attempt to gain access to the water inside. pex water pipe