Study on aging of material for GIS sealing ring

Gas insulated metal-enclosed switchgear (GIS) is widely used in recent years for its high reliability, less maintenance and excellent insulation properties. But with the increasing use of GIS, the defects and failures also appear. According to the statistics, 30%~40% of the GIS defects are caused by SF₆ leakage. And the main reason of SF6 leakage is the defect of the sealing ring. This paper selects two common materials for GIS sealing ring: NBR and EPDM, and puts them in the environment with high temperature and humidity at the same time for aging. After a certain period of time, they are taken out and put to some experiments to test their properties. We can also analyze how the properties change with the aging time by adjusting the experiment period. And it can also be found which material is better as the sealing ring by comparing the properties of NBR and EPDM.