In addition to the standard seal assortment, SNL housings are available, on request, with high-temperature seals, taconite heavy-duty seals with an axial labyrinth, or custom seals for special applications.
For high operating temperatures, up to 250 °C (480 °F), high-temperature felt seals or strips should be used. The felt seals can accommodate circumferential speeds up to 2 m/s. They are identified by the designation suffix CB, e.g. TSN 516 CB.
For additional information about the felt strips, contact the SKF application engineering service.
Taconite heavy-duty seals with an axial labyrinth
Taconite heavy-duty seals with an axial labyrinth (TSN .. NC, fig. 1 or TSN .. NB, fig. 2) can be used under the same conditions as taconite seals with a radial labyrinth. The seals are greased via a hole in the housing cap. Therefore, they can only be used with housings with the suffix T (at the end of a shaft) or the suffix TD (for through shafts).
TSN .. NB seals have a V-ring. It limits the axial movement of the shaft relative to the housing to ±1 mm for shaft diameters up to 65 mm and to approximately ±1,2 mm for sizes up to 100 mm and ±1,5 mm for larger shaft diameters.
Specifications for the seals are listed in table 1.
SNL housings can be equipped with any type of seal that fits the seal groove dimensions in the housing. The relevant dimensions are provided in table 2.
If custom seals are to be used, SKF recommends ordering housings in the SNL 2 series rather than those in the 5 or 6 series. Housings in the SNL 2 series have a larger bore at the shaft entrance and can accommodate a wider choice of seal designs.