General
The rectangular ring RKS is a suitable alternative to the O-ring or WX-ring for static seals with special requirements. In contrast to the O-ring, the RKS rectangular ring has a square cross-section, which generates a higher sealing pressure with considerably better pressure distribution. For this reason, the cross-sectional dimension is slightly smaller compared to the O-ring, with the same groove dimension. Just as with the O-ring, the contact pressure generated during installation is superimposed by the system pressure with this double-acting seal. As a result, the contact pressure increases with increasing system pressure. The RKS is a reliable, static seal in which tight manufacturing tolerances are achieved through a special manufacturing process. This distinguishes them significantly from hose rings or flat gaskets, which are unsuitable for applications of this type due to their coarser tolerances. The rectangular rings RKS are essentially based on the American standard AS 568 A, but can also be manufactured in metric dimensions.
Medium
various media such as mineral oils, water etc.
Material
Standard materials: Elastomers in NBR, EPDM, FKM with 80 to 85 Shore A, in special cases also silicone (MVQ) and HPU
Advantages
- interchangeable with O-rings in DIN/ISO grooves
- no twisting in the groove
- high extrusion resistance, insensitive to gap extrusion
- low mechanical deformation of the cross-section
- good compression set of the compounds
- dimensionally stable during pressure change, little to no relative movement
- no additional support rings required
- excellent relaxation behaviour (sealing behaviour over long periods)
Installation instructions
RKS rectangular rings can be used in DIN/ISO O-ring grooves. In principle, follow the installation and groove dimensions in our O-ring installation tables. For axial-static pressure, the direction of pressure must be observed. With internal pressure the seal should be approx. 1 to 3% larger than the groove outer diameter, with external pressure approx. 1 to 3% smaller than the groove inner diameter. For internal sealing, static application, the internal diameter of the RKS should be selected so that it has the smallest possible deviation from the diameter to be sealed. In case of external sealing, static application, the inner diameter of the rectangular ring should be up to 3% smaller than the diameter of the groove base. To avoid injuries during installation, the RKS must not be pulled over sharp corners or edges. Please ensure that the installation is free of twists. It is also important to select the right material for the respective application. You can find the media resistance in our media resistance list. For special applications, please contact our application engineering department.
Other
The lower deformation under pulsating pressure results in considerably less wear in the groove. Under the above-mentioned conditions, long-term tests have shown an increase in service life by a factor of 8-10.
Range of application
Static seal for higher requirements in plant and machine construction as well as in the automotive industry
