Hebei Hankai 25x47x7 oil seal
The mention of 55%, 80%, and 10% in relation to oil seals might reflect various metrics or considerations concerning their performance and application. For example, in many mechanical systems, seals can be categorized based on their efficiency, effectiveness in preventing leakage, and their material composition. A 55% rating might refer to a baseline performance measure for standard oil seals, whereas an 80% rating could indicate high-performance seals designed for rigorous applications. On the other hand, a 10% figure could relate to the failure rate or the operating conditions under which these seals can be compromised.
55 80 10 oil seal


25x38x7 oil seal. Signs of a failing seal include oil leaks around the seal, excessive noise or vibration from the machinery, and a decrease in performance or efficiency. If any of these symptoms are present, it is important to replace the oil seal promptly to prevent further damage to the machinery.
Operating temperatures for engine oil seals (see Fig. 14.11 and cross-section of lip seal with garter spring in Fig. 14.22) vary widely, depending on engine design and location within the engine. Typically, the rear crankshaft seal is subjected to much higher temperatures than the front seal. Oil sump temperatures vary considerably, depending on provisions for oil cooling. This allows use of hydrogenated nitrile (HNBR), silicone, or acrylic elastomers for some seals in relatively low-temperature environments (120–140°C or 250–284°F). Standard fluoroelastomers (FKM), bisphenol-cured VDF/HFP/TFE terpolymers with 68–69% fluorine content, perform well in oil service up to about 160°C (320°F). More resistant fluoroelastomers are necessary for reliable long-term performance in more severe environments.