the aim of this study is to improve knowledge on the incompressibility and on the extrusion resistance of rubber seals. Under hydrostatic pressure, some irreversible damages may appear on the elastomer seals due to extrusion in the space gap, created by component design or dimensional tolerances. Cetim carried out an analysis of experimental results obtained by Roxel company on an O-ring. The elastomeric seals were tested with a specific device which can impose extrusion conditions. This paper focuses on the experimental results obtained by material testing and on the investigations carried out for final products for industry, i.e. seals. Furthermore, Cetim and LRCCP have led many studies to understand the mechanical behaviour of rubber under high load. In the recent studies, an HNBR reference was studied under hydrostatic compression cycling with extrusion gap. The recent results are exposed in this paper to provide a better link with the industrial applications.