MLP Pipe

The multilayer pipe (MLP) used for the Bute-Gasline Gas System consists of 3 layers: an outer yellow PE-Xb layer then aluminium and then an inner black PE-Xb layer. This is sometimes abbreviated as "PEX-AL".

Regardless of brand, PEX pipes are manufactured via 3 methods (A, B or C) but contrary to popular belief, these letters are not grades of PEX and have nothing to do with the quality or performance of the pipe. The letters are used merely to identify the manufacturing process and in fact, all types of PEX pipe must adhere to the same standard in terms of:

  • Pressure and temperature ratings
  • Minimum bending radius
  • Pipe wall thickness an inner diameter/outer diameter dimensions (subject to manufacturing tolerances).

In brief, there are 3 main manufacturing processes used to produce PEX pipe:

  • A (Peroxide or “Engel” method): HDPE polymer is melted, creating free radicals and the cross-linking of molecules occur at temperatures that exceed the polymer’s decomposition temperature.
  • B (Silane or Moisture Cure method): Cross-linking of the HDPE polymer molecules is done after the extrusion process using a catalyst and by exposing the PEX tubing to water (steam bath). This is probably the most common manufacturing process, and Pexline PEX pipe is made using this process.
  • C (Irradiation or Cold Cross-linking method): After extrusion, the pipe is exposed to an electron radiation beam. The radiation allows the breaking of existing bonds between the polymer’s molecules and initiates the cross-linking process.

The PEX-b pipe that is used is made using the Silane or Moisture Cure method. PEX-b pipe has the highest bursting pressure compared to PEX-a and a similar or better resistance to oxidation – a very important factor for plumbing installations. Furthermore, PEX-b pipe has been in use for over 40 years with no known issues – offering peace of mind.

The Gasline Gas SystemGasline_Pipe Coils CC_WEB 402x320 tiny.png

The Gasline Gas System complies with the Australian and New Zealand joint standards AS/NZS 4176.8 and is ISO Type 5 approved.
The Gasline system is quality controlled and also tested in-house, covered by extensive worldwide patents.
There is a 25 year guarantee when installed by a licensed gasfitter in accordance with the Gasline Technical & Installation Manual as well as local and national gasfitting regulations.


This website uses cookies to optimise your experience.
By continuing to use our website you are agreeing to our Privacy Policy and Cookie Policy.
Accept and close this alert or Read Privacy Policy