A triangular groove is used to seal covers and flanges using O-rings. The groove represents the installation space into which the sealing element is inserted during installation.
The triangular groove is a rare form of groove geometry. It is much more common for the installation space to be designed as a rectangular groove. With the rectangular groove, the O-ring is pressed between two sealing surfaces: The base of the groove and the surface of the cover.
An O-ring in a triangular groove, on the other hand, is in contact with all three surfaces of the triangle. This means that the elastic deformation of the O-ring required for the sealing effect cannot reach a defined value.