Aging and service life prediction of O-ring seals

Department 3.4 at BAM tests the safety of storage containers for radioactive waste. Elastomer seals are also used in such containers and their service life can be several decades. For this reason extensive investigations into the ageing and service life prediction of elastomer seals were carried out as part of this work. This provided in-depth knowledge of how different classes of elastomers age and how the service life of O-ring seals can be determined. Artificial ageing was carried out on three materials at four temperatures. The samples which were aged for up to 2.5 years were analyzed using various methods to characterize material damage and sealing behavior. The results show that the seals remain tight under static conditions even when the material properties have already changed significantly which is evident for example in the hardening of the originally rubber-like material. In addition to the material properties the properties of the sealing system were also investigated which are more informative in terms of sealing capability.