• Mechanical
  • Maintenance and Troubleshooting Tips
  • Other important factors are ensuring the hardness and roughness of the shaft are correct. A shaft hardness of HRC 45 is recommended for a rubber sealing lip, with a roughness of Ra 0.4-0.8. A higher shaft hardness of HRC 60 and shaft roughness of Ra 0.1-0.4 is recommended for a PTFE lip.

  • 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.

  • In conclusion, the unassuming 20mm rubber gasket is a silent hero in numerous industries. Its standardized dimensions and reliable material properties make it an essential component in maintaining the efficiency and safety of machinery across various sectors. It is a prime example of how everyday objects can have extraordinary impacts, safeguarding our environments, securing our infrastructures, and supporting the smooth operation of industry at large.
  • The main causes of external lubricant leakage from pumping systems, hydraulic machines, gearcases and sumps are the wrong selection, improper application, poor installation and inadequate maintenance practices that are applied to sealing systems.

  • Polyacrylate is a great compromise between cost and quality. It has a high performing temperature and chemical range, but not to the extent of the range of Viton. The temperature ranges from 31°C to 148°C (-25°F to 300°F). Polyacrylate is primarily used in automotive transmissions and hoses but also found in shaft seals, gaskets and o-rings, due to offering a high resistance to hot oil and oxidation. While Polyacrylate is a great alternative to other high temperature resistant materials that are more expensive, it does have a poor water compatibility and cold flexibility. The best situation for Polyacrylate is an environment where heat and oil resistance but cost is the major issue. And while these 4 different materials cover a wide range of applications, there are even more materials out there designed for very specific niches in mind.

  • FEPM-7506