PEX/AL/PEX piping comes in nominal pipe sizes (NPS) ranging from 3/8 to 2¼, also labelled as diameter nominal (DN) sizes from 12 to 75. PEX/AL/PEX piping has pressure ratings of 200 psi at 73ºF (1380 kPa at 23ºC) and 1 25 psi at 180ºF (860 kPa at 82ºC). Consult the specific PEX/AL/PEX piping manufacturers' literature and listings for appropriate pressure ratings. PEX/AL/PEX piping is typically sold in coils and straight lengths.
Definition
PEX/AL/PEX piping is a coextruded crosslinked polyethylene composite pressure pipe with a welded aluminum tube reinforcement between the inner and outer layers. The inner and outer crosslinked polyethylene layers are bonded to the aluminum tube by a melt adhesive.
Overview
PEX/AL/PEX piping is a high-temperature flexible plastic pressure pipe with over 30 years of successful use in the European market, including extensive testing for durability and material performance. It was first introduced in North America in the early 1990s. Today, it is used for plumbing, hydronic heating and cooling, and snow and ice melting systems. PEX/AL/PEX piping is approved in all model plumbing and mechanical codes across the United States and Canada.