The flexible plastic known as PEX water pipe is replacing traditional copper and galvanized steel in residential plumbing systems. Although it’s still relatively new to most homeowners, plumbers are well acquainted with the advantages and benefits of this type of piping for hydronic heating and geothermal systems as well as water supply lines.
PEX is a cross-linked form of HDPE (high density polyethylene) tubing that undergoes a physical or chemical process to change its molecular structure. This process increases the pipe’s strength, elevated temperature performance and resistance to slow crack growth.
During the manufacturing process, free radicals are introduced to the HDPE material, creating cross-links between its molecules. This allows the tubing to withstand higher temperatures than traditional non-cross-linked HDPE, such as the plastic piping used in water distribution systems and residential fire sprinklers.
There are several ways to connect PEX pipe, but the quickest and most reliable is with push fit fittings. These are easy to install and no special tools are required. They also offer a more secure connection than crimp rings or pinch clamps, but some plumbers are skeptical of their longevity and trustworthiness in sealed, interior spaces like basements and crawlspaces.
Another option for connecting PEX is with the fusion method, which uses heat to melt and fuse the ends of the pipe together. This creates a durable and permanent connection that is suitable for both hot and cold water applications. PEX-A and PEX-B both use this technique, but PEX-A is more durable than PEX-B. This is due to the fact that PEX-A is manufactured using a moisture cure while PEX-B is made via an irradiation process. pex water pipe