PEX-ALUMINUM-PEX COMPOSITE (PEX-AL-PEX)
IntroductionPEX-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.
- Safety of potable water and long-term reliability
- Resistance to corrosion, tuberculation, deposits
- Flexibility combined with stiffness to hold its shape
- Less linear longitudinal thermal expansion/contraction than standard PEX
- Aluminum layer prevents oxygen from permeating into pipe
- No flame used for joining, many fitting and joining options
- Durability and toughness to survive jobsite installations
- Lightweight, compact, easy to transport
- Hot- and cold-water plumbing distribution, residential and commercial
- Radiant heating and cooling systems (floors, walls, ceilings)
- Hydronic piping and distribution (radiators, fan coils, etc.)
- Turf conditioning/pitch heating
- Outdoor snow and ice melting
- Chilled water piping
- ASTM F1281 - Standard Specification for Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Pressure Pipe
- CSA International B137.10 - Crosslinked polyethylene/aluminum/crosslinked polyethylene (PEX-AL-PEX) composite pressure pipe systems