Static sealing ability
A leakage from the cylinder via the rod is not always caused by a defective dynamic sealing function. A failing static function of the rod seal may also cause leakage via the seal housing groove.
The decisive factors are the surface roughness value of the seal housing groove in relation to the hardness of the seal material, the design of the sealing edge and to a certain degree the possibility for the seal to move axially in the seal housing groove.
It can be difficult to achieve a satisfactory surface roughness value at the base of closed grooves. A change to an open groove, designed for assembly with our retainer ring type RI, facilitates the machining methods in order to achieve a satisfactory surface roughness value. An open groove also simplifies the cleaning of the groove, the control of the surface roughness value and the assembly (fig 1).