Crosslinked polyethylene pipes for hot water supply are required high mechanical strength and high creep resistance at high temperature. Especially PEX-a pipes which are made by peroxide crosslinking have better performance such as high degree of crosslinking, creep resistance and shock resistance than the pipes made of other crosslinked methods.

In this study, the PEX-a pipes which were mixed with several stabilizers were tested to examine the effects on degree of crosslinking and oxygen induction time. And also they are tested to evaluate the performance of long term hydrostatic pressure test and long term circulating chlorinated water test. As a result, it was found the combination of stabilizers for PEX-a pipes to prolong the oxygen induction time without inhibiting the crosslink-ing. It was found, moreover that the PEX-a pipes with this combination of stabilizers has good performance for long service life. This shows that the long-term durability of PEX-a pipes was able to evaluate by the type of stabilizer, measurement of oxygen induction time and degree of crosslinking.