Tuesday 31 January 2017


Posted by at 7:37 AM

PEX Tubing


PEX tubing is the single most important part of any radiant install, and alot of people dont know the different options out there. Many just go to a box store and ask for PEX but is it really that simple.

What is PEX?

PEX tubing is made from crosslinked HDPE (high density polyethylene) polymer. The HDPE is melted and continuously extruded into tube. The crosslinking of the HDPE is accomplished in one of three different methods. Crosslinking is a chemical reaction that occurs between polyethylene polymer chains. Crosslinking causes the HDPE to become stronger and resistant to cold temperature cracking or brittleness on impact while retaining its flexibility. The three methods of crosslinking HDPE are the Engels method (PEX-a), the Silane Method (PEX-b), and the Radiation method (PEX-c). All three types of PEX tubing meet the ASTM, NSF and CSA standards. GBT's standard PEX is made using the radiation method and is a PEX-C.

What is PEX-AL-PEX?

The main and most distinctive feature of PEX-AL(Aluminum)-PEX is the internal layer of aluminum, “sandwiched” between two layers of PEX. This layer adds memory feature to the tubing and allows it to retain the shape to which it was bent. Memory feature is very useful in all PEX project types and allows for a 1-person installation. Aluminum layer also provides an oxygen diffusion barrier with no need for additional coatings. Pressure ratings of PEX-AL-PEX are also higher than that of the regular PEX.


  • Multi layer PEX
  • Oxygen barrier or non-barrier options
  • Multiple fitting types can be used
  • Has memory so tends to return to coil shape
  • Expands 7" per 100'
  • Made in USA
  • 31 year warranty
  • Sized by copper standards
  • Potable water approved


  • ?Aluminum core
  • ?Oxygen barrier
  • ?Stays where you put it
  • ?Easy compression fittings or permanent press
  • ?Expands 1” per 100’
  • ?Imported
  • ?10 year warranty
  • ?Sized by ID