External forces acting on the rod can cause pressure peaks. They can be far in excess of the system operating pressure and may press a rod seal into the gap between the piston rod and the cylinder head. This risk of gap extrusion can be avoided for rod and buffer seals by using anti-extrusion rings. These hard and temperature-resistant rings can be integrated in the seal or a separate full-face anti-extrusion ring can be used. This ring can be added to a rod seal by simply extending the housing length (fig. 1). Integrated anti-extrusion rings fit into a notch in the rod or buffer seal and do not need an extended housing length.
DZR (fig. 2) profile rod seals and RBB (fig. 3) profile buffer seals incorporate an anti-extrusion ring. Other U-cup and energized U-cup rod seals with an integrated anti-extrusion ring are available on request. Full-face anti-extrusion rings for rod and buffer seals, for example BUS profile, are not covered in this section, but are available also on request. For seals without an integrated anti-extrusion ring, SKF provides full-face anti-extrusion rings on request. For additional information, contact SKF.