16x2mm PEX-A underfloor heating pipe

the pipe with the oxygen barrier is a polyethylene pipe crosslinked with peroxide TRIGONOX 311 (Akzo Nobel). Through the special cross-linking process, the polyethylene molecules are united in a three-dimensional structure that gives the pipes resistance and durability, superior mechanical and thermal characteristics for use in heating installations.

The pex-a polyethylene pipe has a high cross-linking factor (>70%) for superior resistance over time.

The peroxide cross-linking technology produces a denser PE-Xa pipe with excellent mechanical properties due to the shorter molecular bonds compared to polyethylene cross-linked by other processes. At the same time, there is also the advantage of a better controlled reticulation because it occurs during extrusion and immediately after it.

To create the oxygen barrier, the EVOH (ethylene - vinyl alcohol) copolymer is used, which is added to the entire outer surface of the pipe. It has three oxygen barrier layers (EVOH) bonded with specific adhesive (maleic anhydride).

The role of the oxygen barrier:

prevents the formation of microorganisms that would settle on the inner walls of the pipes;
reduces the corrosion of the metal elements with which the heating water comes into contact (heating and junction equipment);
it protects the pipe from free oxygen atoms that can combine with hydrogen atoms from the molecular structure of polyethylene and that over time lead to the aging phenomenon of the pipes.
The speed of gas diffusion is measured in cm3 of gas that pass through the 20 micron thick polymer film on a surface of 1 m2 for 24 hours. The behavior for EVOH and polymer is:

EVOH – 0.2;
PE – 12,000.
The difference is much smaller in the case of the copolymer and thus explains the need to use PEX with an oxygen barrier!

Technical specifications:

dimensions: 16×2 mm;
nominal pressure: 10 bars.
thermal conductivity: 0.38 W/m2K;
maximum temperature of the working fluid: + 90ºC;
600m coil.