Pipeline systems made of plastics: ― unlimited working life?

摘要

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 results on modern bimodal pipe resins the different failure mechanisms will be explained and differences to the second-generation PE material demonstrated. One can conclude that -professional handling and design provided-the durability of modern pipe systems is only limited by the thermo oxidative ageing of the material. Practical experience for 45 years show quite clearly that plastics pipe systems do not "fade away" after the end of the service life guaranteed in the relevant standards. However, whether this service life will last for more than one thousand years, cannot prove the question.