Otto, Schulte, Feldmann
PE-X & Other Pipes # 1998 Gothenburg
The development of a large aeroplane with two decks and a capacity of more than 500 passengers yields numerous problems in structural design, logistics, passenger systems etc., including special requirements for the fresh water supply system. The reliability of this system is very important, especially during long distance flights, because any disturbance impairs the comfort of the passengers. For that reason it is the aim of a joint project with multiple partners including AIRBUS Industries to develop a new water system technology with enhanced features concerning filling and drainage, ice guard and flexible connection capabilities as well as weight and energy consumption. As the existing steel pipes are not able to meet all these requirements well enough, efforts must be undertaken to replace them by tubes with nonmetallic materials.
Some of the disadvantages of the steel piping are related to the necessary preproduction of pipe bends, to the difficulties associated with a subsequent change of the setup, as well as to insufficient insulation. Plastic pipes on the other hand exhibit several features such as low bending stiffness, low thermal conductivity and a low density. Besides, they have a lower surface roughness than most of the metal pipes, so a decrease in deposition and flow resistance can be expected. For a reliable design with polymer pipes it is important to consider the environmental conditions because in contrast to metals the mechanical behaviour of plastics is strongly dependent on time, temperature and stress. Figure 1 shows a list of the most important requirements such as a wide service temperature range, flame resistance and chemical resistance against various disinfectants and other liquids.
Related papers
Author(s) : Ulrich Schulte, Dr. -Ing. Joachim Hessel
In order to protect the Austrian lakes effectively against the discharge of effluent, a 13 km long pressure pipeline made of high density polyethylene was laid on the bottom of Lake Ossiach back in 1971. The DN355 to DN200 pipes were produced from a first generation HDPE-compound. The classification would have been...
Author(s) : Stephen Beech, Christophe Salles, Ulrich Schulte
Polyethlyene, Pipes, Buttfusion, Joining, Testing Several well established procedures are used for butt fusion welding of PE pipes globally. The most widely used are the European Single Pressure, UK Dual Pressure, and the USA High Pressure procedures. In the future it may be possible to rationalise these procedures....
Author(s) : Ulrich Schulte, Heinz Vogt, Hans-Friedrich Enderle, Dieter Lilge
The completion of a pressure test is mandatory for all new pipe systems. Its purpose is to demonstrate the overall leak-proof condition of the system. In the course of this test, HDPE pipes of SDR 17 class are exposed to high stress loads. In an extensive test programme, all failure mechanisms observed in long-term...
Author(s) : Schulte
After the discovery of the low-pressure process for the production of polyethylene with the aid of Ziegler catalysts, only another year went by before pipes were being extruded in highdensity polyethylene. In the same year, at the end of 1954, Hoechst had already begun to carry out long-term failure tests on HDPE...
Author(s) : U. Schulte
There are three factors that can influence the service life of plastics pipes: mechanical overloading, environmental stress cracking and degradation caused by oxidation at high temperatures. This article deals primarily with the degradation that occurs during processing at high temperatures and also – as an...
Author(s) : Berthold, Boehm, Enderle, Lackner, Lilge, Schulte
The new generation pipe materials PE 100 are now well positioned in the market because of their unusual combination of mechanical properties. Major advantages are high resistance versus slow crack growth combined with superior stiffness. These new PE 100 resins show very high long term hydrostatic strength for...
Author(s) : Schulte
Lifetime expectations play a major role when selecting materials for pressure pipes. Information on the service life of a piping system made of polyethylene can be gained from the creep rupture tests at various temperatures being evaluated by standardized extrapolation methods (ISO/TR 9080). With the help of test...
Author(s) : Berthold, Boehm, Enderele, Groebel, Lueker, Lecht, Schulte
Recently Business Unit Polyethylene of Hoechst AG developed a Ziegler-catalyst-system providing very high catalyst activity even in presence of high hydrogen concentrations. The catalyst is applied to an appropriaie Z-stage-polymerization process. This technology is carried out in a modern, fully automated production...
Author(s) : Schulte
Author(s) : Vogt, Enderle, Schulte, Hessel
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