The term rod seal refers to the installation type of O-rings. If they are pressed radially between the sealing surfaces in the installation position, they are a rod seal. In the case of compression in the axial direction, on the other hand, this is referred to as a flange seal. While flange gaskets are mainly used for stationary components, rod gaskets often seal moving components.
The installation groove for rod seals can be located in the inner or outer part of the seal. This feature can be used to further subdivide rod seals:
- Rod seal: groove in the outer part (internal sealing)
- Piston seal: groove in the inner part (external sealing)