PEX is very similar to polyethylene in appearance but, because of cross linking, is a thermoset material, it does not melt. It is highly flexible and easily coiled.

PEX is approved in all North American model plumbing codes for hot and cold potablewater distribution systems.

The PEX-AL-PEX composite capitalizes on the corrosion and chemical resistance of plastic and the pressure capacity of metal by laminating the aluminum layer between layers of plastic. The resulting tubing is non-corroding, bendable for form stability, flexible, and resists most acids, salt solutions, alkalis, fats, and oils.

Composite pipes (PEX-AL-PEX or PE-AL-PE) are used in residential and commercial plumbing and in pressure service on compressed air and compressed gas systems.