The main difference in between PEX-AL-PEX pipe and the other PEX varieties is how it's made. PEX-AL-PEX tubing is made by putting a layer of aluminum in between two layers of PEX, which ensures a resilient and sturdy tube. This type of PEX tubing has the highest pressure rating out of all PEX and has a memory feature that allows the tube to retain its original shape. It's mostly used in radiant floor heating, radiant heating systems, and snow melting applications. Canarsee carries PEX-AL-PEX pipes that are compliant with: pw-G, cl-TD , NSF-pw, ASTM F1281, CSA B137.10.