MT Multilayer Pipes for Gas Installations Inside Buildings

The only pipe materials for gas installations inside buildings in Germany and most of Europe used to be metals for a long period of time. Especially screwed steel pipes and soldered copper pipes have been installed. During the last few years also press systems made of copper were established. In contrast to this rather reserved and cautious development (gas installations require responsible and well-reasoned developments) plastic and multilayer pipes have been used in plumbing and heating applications for about twenty years now. The market share of plastic and composite pipes is still rising, even though no other group of materials is subject to such extensive and restrictive standards and regulations like polymeric materials. PE-X pipes have been used in the Netherlands for indoor gas installations for a couple of years now. Quick installation and high flexibility are the main advantages of these systems. Based on these experiences the stable-in-form composite pipes – which combine the advantages of flexible PE-X pipes with those of odour-proof and stable metal pipes – have entered the market as the latest development. The main emphasis of these developments was laid on the security concerning fire resistance and manipulation. Various tests were developed and carried out for this purpose, e.g. the pipes and fittings were exposed to temperatures up to 900°C. To minimise the possibilities of manipulation additional gas-flow-valves and non-return-valves have been implemented.