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.
