The major cause of extrusion and nibbling is stress caused by high pressure. This is commonly noticed when the oil seal has a chipped or nibbled look. In fact, in some cases, the surface of the seal tends to peel on its own, which makes it have a shaved look. What the stress does is that it increases the clearance gap between the mating edges, which causes the seal to get entrapped, and then leads to severe physical damage.
Once you have selected the most suitable seal available, considering the environment, temperature, shaft speed, pressure, lubrication availability, as well as the size, of course, the seal should be stored adequately and then fitted properly. Here are a few suggestions that could help:-
Shaft Surface Finishing
For more severe oil-seal service at temperatures of 160°C (320°F) or higher for extended periods, more resistant fluoroelastomer compositions are required for long service life. High-fluorine VDF/PMVE/TFE elastomers, along with TFE/olefin FEPM elastomers, are much less susceptible to attack by oil additives. TFE/P fluoroelastomers have the requisite chemical resistance, but have low fluorine content, leading to relatively high swell and to soft vulcanizates with lower wear resistance than desired.




Nitrile Butadiene Rubber (NBR, nitrile)
