Plastic Pipes Conference Association # 2012 Barcelona
Thorsten Späth
The use of plastic pipes is very common in many applications such as pressure less sewer pipes as well as pressure pipes up to a limited pressure level. This limit is naturally given by the moderate strength of plastic materials compared to metallic materials such as steel. Corrosion resistance and the high flexibility of polyethylene combined with fibre reinforcement give a synergy and open the way to new applications. Therefore custom-made multilayer pipe structures are state of the art products for high pressure applications. An up-coming approach is to use self-reinforced high pressure pipes, which are known as monocomposites and consist to 100% of one material e.g. polyethylene. The secret of the monocomposite structure is an integrated layer of highly oriented polyethylene tapes. This allows operating pressures twice as high compared to common polyethylene pipes without losing the beneficial properties such as lightweight, easy weldability, high flexibility and corrosion resistance. The modular structure of PE 100-RC inner layer, reinforcing tape and weldable outer layer enables to design the pipe for different operation requirements such as point load resistance, increased pressure rates and elevated temperatures. The strength of the composite pipe can be varied in a wide range by the ratio of reinforcement. New applications for the monocomposite high pressure PE pipe are high pressure gas or water pipes or industrial applications e.g. onshore pipelines or salt water applications. A whole system including welding couplers, mechanical transition pieces in connection to steel is approved by the third party inspection of TÜV Süd in Germany and several projects in Europe have proven the excellent handling benefits in practice and on the commercial point of view the capability of competing against traditional materials was reported. For this a technological and economical benchmark of plastic and steel pipeline systems for high pressure gas distribution networks done by KIWA Gastec proved this competitiveness by comparing realistic case studies.
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Author(s) : T.Spath
Polyethylene is a thermoplastic material that has very balanced properties and therefore established itself as standard material in piping construction both for the supply of water and also for the low and medium pressure range distribution of gas. However it has not been possible to use the plastic pipeline in the...