Gas Pex Couta Group

Technical Information.

The Water Pex™ Piping system || Resources


Technical information

The Water Pex™ piping system is available in 2 differing styles. These include:

1. Pex/Al/Pex

This is a five layered macro-composite construction and is the latest innovation for low pressure gas and water applications. The inside layer is made of cross-linked polyethylene (PEX). This is bonded to an overlapped welded aluminium layer which in turn is bonded to an outside cross-linked polyethylene PEX layer. The middle layer is 100% gas/oxygen tight and all layers are extruded in one step. Water Pex™ Pex-Al-Pex pipe combines the benefits of both metal and plastic pipes. The inline welded aluminium tube is absolutely safe against oxygen penetration. It compensates for the snap-back forces and the linear expansion caused by temperature changes. The basis of the system is simple, safe and fast pipe installation: simply bend by hand, cut to length, ream and bevel, join together, screw or press, done.

This structure provides the pipe with the advantages of metal and plastic while avoiding their weaknesses, and brings the following benefits to plumbing

  • it is lower in cost when compared to conventional copper systems
  • it is lightweight, bendable and does not need to be welded
  • installation times are significantly reduced, saving labour costs
  • the product is hygienic, non toxic and smooth

The pipe is available in 16mm, 20mm and 25mm diameters. Colours include:

a. Blue (Cold water)
b. Red (Hot Water)
c. Lilac (Recycled water)
d. Green (Rain water)

2. Pex-b Multi-Purpose

The pex-b piping is a lower cost general purpose piping system for water only. The inner layer of the pipe is constructed from pex-b material. Bonded to the pipe is an
outer coloured layer that provides the product with increased UV resistance making it suitable for external applications. This piping system is available in a range of colours to make installation quick and easy and comply with National regulations. The available colours include:

a. Black Multi-purpose water pipe
b. Blue Cold water
c. Red Hot Water
d. Lilac Recycled water
e. Green Rain water

Pipe is available in sizes 16mm, 20mm, 25mm and 32mm.

Both systems have been independently tested and certified to demonstrate that they meet the requirements of the respective Australian Standards. In addition the manufacturing facilities are independently certified to ISO 9001.

3. System design and application classifications

Application conditions and classifications of the pipes. The basic Water Pex™ Pex-Al-Pex and Pex b piping system components can be used in the areas of domestic and commercial plumbing such as hot and cold water, under floor heating & radiator heating.

Materials Applications Service Temperatures Max. Working Pressure
PEX/AL/PEX Hot and cold water supply, under floor heating,
radiator heating etc.
-40º~+95º PN14
PEX-B Hot & cold water supply, under floor heating, fire protection, radiation heating -40º~+90º 16mm - PN16
20, 25 and 32mm - PN12.5

4. Burst pressure Pex-AL-Pex & Pexb

All burst pressures quoted at 25 Deg C

  • Pex-AL-Pex 16mm pipe=7.6 Mpa 20mm pipe 5.8 Mpa, 25mm pipe=5.2 Mpa
  • Pex b 16mm = 6.2Mpa 20mm =4.8 Mpa