Maintenance and Replacement of Spark Plug Wires and Spark Plugs

Vulcanizates of several fluoroelastomers, listed in Table 14.1, were exposed to a standard 5W-30 engine oil, ASTM Service Fluid 105, for up to 6 weeks at 150°C (302°F).⁵ The oil was changed weekly, but was not aerated. Retained elongation was measured after exposure for 1, 2, 3, and 6 weeks; data are shown in Fig. 14.3. The results indicate that bisphenol-cured FKM-A500 VDF/HFP copolymer, FKM-B600 VDF/HFP/TFE terpolymer, and peroxide-cured FEPM-7456 TFE/P/VDF terpolymer lost most of their original elongation over the course of the test exposure, indicating considerable additional cross-linking occurred by reaction with amine- and phenol-containing oil additives. The other fluoroelastomers showed better retention of elongation, being much less susceptible to additional crosslinking. Note that FEPM-7456 contains a high level of VDF (about 30%), while FEPM-7506 contains a relatively low VDF level (10–15%) to serve as cure site for bisphenol curing. The other FEPM types contain no VDF.

1) Common seal types and their features

Before fitting the oil seal, it is essential to check that the oil seal, shaft and bore are clean and undamaged. The surfaces the oil seal will come into contact with must be free of sharp points or burrs. The sealing lip is fragile, so even minimal damage can cause a leak. It is also important that the shaft and bore are correctly finished.

In choosing the right oil seal type for your application, it is essential to assess factors such as speed, temperature range, pressure levels, chemical compatibility, shaft material, and installation space limitations. By considering these factors carefully, you can ensure that you select an oil seal that will provide optimal performance and longevity in your specific application.

6. Proper installation is key to effective oil seal performance.

Silicone oil seals, which are also called VMQ, have strong resistance to temperature, which ranges from -140 degrees Fahrenheit to 392 degrees Fahrenheit. They are also resistant to ozone, light, and harsh weather conditions. Silicone is frequently used in hydraulics and pneumatics, as well as in the food and medical industries. Due to the material’s transparency and flexibility, it’s commonly chosen for the manufacturing of o-rings, molded parts, and flat seals, as well as electrical insulators.

Oil seal type or shape

If you are looking for the highest temperature resistant oil seals, Perfluoelastomer can go up to 600°F. If you are more concerned for low temperature, Chloroprene can go all the way down to 40°F, which is why it is used most commonly for refrigeration. And if FDA applications or medical devices are your primary concern, Butyl , the all petroleum compound, will be your best choice. As you can see, when choosing the right material to work with, you must analyze several other key components to help choose the right one. 

How are they used?

Another factor you need to consider is the type of lubricants that are more suitable for the seals. Check for the appropriate viscosity of the lubricant that’s compatible with the seal material.

The primary function of a shaft oil seal is to retain lubricating fluids within the system while preventing the ingress of external contaminants. This is particularly important in high-speed applications where the loss of lubricant or the entry of contaminants could lead to rapid wear and damage to the equipment.