These types are made with a metal outer case and a PTFE lip. They are suitable for a wide range of temperatures from -90 °C to +260 °C.These lip seals can also be used for higher pressures of up to 10 bar (special types up to 25 bar) and rotational speeds of up to 40-45 m/s. Certain grades of PTFE are suitable for use in pharmaceutical and food applications. One important point is that PTFE lip seals do require a shaft with a harder, smoother finish.
If the seal is being fitted to original equipment you may have some influence over the shaft and housing bore finish, but if you are replacing a worn seal you still need to take into account the condition of these 2 essential parts.
valve cover gasket cover. The choice of material depends on the specific requirements of the engine and the operating conditions it will encounter. For example, engines that operate at high temperatures may require a gasket made from a heat-resistant material, while those subjected to extreme pressure may benefit from a gasket with enhanced strength and durability.2. Temperature: Just like pressure, it is very important to choose the right seal that can withstand extreme heat or cold temperatures, depending on the operating environment of your application.
Oil seals with outer metal cases may include finishes or treatments applied to the outer edge to aid in rust protection, identification, and sealing of scratches or imperfections in the housing bore. Common finishes applied to the outside edge of metal O.D. oil seals include plain (a bonding agent of usually a yellowish-green color), a color-painted edge, and a grinded-polished edge.
Oil or other seals can be used for grease and oil seals. A flexible lip, radial lip, or rotating shaft seal are different names for an oil seal. Single lip, double lip, triple lip, and four or more lips are frequent configurations. Double dust lip seal A seal with a garter spring design is the Double Dust Lip (DDL) seal. It has two dust lips, as the name would imply, plus a fluid lip with a garter spring to keep the lip firmly attached to the wear ring. Given the ongoing evolution of bearing seal designs, this seal would be considered a starting seal. For more than 50 years, this design has been the workhorse of the freight business; it still is in some regions. NBC Brenco Bearing Seal performs the fundamental task of keeping contaminants and grease out. Because of the garter spring, this seal would add the most torque and temperature to the bearing. Efficiency plus bearing seals Due to eliminating the fluid lip using poly inserts and rotors, the Efficiency Plus (EP) seal has a reduced torque value of fewer than 15 in-lbs. Although it features a triple dust lip rather than a double dust lip, the dust lip is still a molded component of the design. A labyrinth-like insert and rotor interlock each other to replace the fluid lip. NBC Brenco labyrinth provides excellent grease while lowering the torque required to rotate the seal. Other types of oil seal and grease seals include:
Figure 2.10. Garter spring
Make sure the fuel-pipe connections are clean. Unplug them and reconnect to the pump.