Recommendations for dynamic sealing surfaces
The dynamic sealing surfaces on the piston rod and in the cylinder bore (fig. 1) require similar, but somewhat different surface finishing.
Piston rodThe recommendations for the piston rod sealing surface (table 1) assume that typical materials and processes are used to manufacture the piston rod by induction hardening a carbon steel rod, grinding, hard-chromium plating and then polishing it to achieve the specified diameter and finish.
For alternative rod materials and coatings, other surface specifications, finishing methods, seal materials and designs may be required. Examples of such alternative rod coatings include:
- various hard metals applied by high velocity oxygen fuel (HVOF)
- ceramic coatings of various compositions and finishes
- stainless steel
- iron nitride
For recommendations for sealing systems with alternative rod materials and coatings, contact SKF.