Durability Evaluation of PE Pipe for Hot Water Application Under Various Test Conditions

Abstract

This paper describes comparison of test results between the conventional hydrostatic stress rupture test and various accelerated durability tests considering the actual using condition using polyethylene pipes for heating and hot water supply containing a relative small amount of antioxidants which have low mobility in a resin. It was found that the dissolved oxygen in hot water and the diffusion factor of oxygen in a resin affect the degradation of a pipe. It was also clarified to the temperature dependence of oxidative degradation by the hot water circulation test and copper ion aqueous solution circulation test and to the mechanism of generation of thermal degradation by copper.