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Extreme Bearing - Model CC and CL -Chemical Resistant Seals
The CC and CL chemical resistant bearing seals are designed for challenging applications, particularly in harsh environments such as sea water, chemically corrosive conditions, or extreme temperatures. These seals incorporate a PTFE sealing lip and a stainless steel housing, offering robust resistance and durability. The CC type features external dual lips to flush out dirt and excess grease, thereby protecting the bearing housing from contaminants. Conversely, the CL type is maintenance-free, equipped with an additional lip to retain grease within, ensuring efficient operation without the need for frequent re-greasing. PTFE's properties provide a tight fit around the shaft, minimizing dirt infiltration, but care should be taken with abrasive contaminants. Proper shaft hardening in the seal contact area is recommended, with a minimum hardness of 45 HRC and potentially up to 60 HRC, to enhance performance and lifespan. While PTFE shows resistance to many chemicals, it is affected by certain substances under specific conditions.
CC and CL bearing seals
Perfect for use in sea water and other harsh environments!
The combination of bearing shaft seals featuring a PTFE sealing lip and a stainless steel (grade 316) housing make this sealing solution a good option for difficult and extreme conditions. Ideal for use underwater at sea, in dirty environments, for applications with corrosive chemicals or extreme temperatures. There are two types of PTFE seal available and one of them is maintenance-free for the lifetime of the bearing unit – so grease it and forget it!
Key properties
PTFE from Polyfluor has the following properties:
- Dual or triple PTFE sealing lip
- Works under high pressure up to 40 bar
- The ideal choice for high speeds of up to 30 m/s
- For wide temperature range from -79°C up to 260°C
- Excellent chemical resistance
- Suitable for food and pharma applications (FDA-approved)
- Good dry running capability
- Wear-resistant and low friction
- Greatest resistance to fatigue
- Flame resistant – UL94V0
- Antistick properties
- UV-resistant (does not age)
These seals are useful for problematic applications such as where temperatures are extreme or chemical resistance is needed. Extreme Bearing supplies two standard types of PTFE lip seals.
CC flushes dirt away
The CC type is the version with two lips placed on the outside to keep the elements and unwanted contaminants out of the bearing housing. When the housing is filled up with grease, the lips will release the excess grease and discharge the contamination from the sealing surface.
CL is maintenance-free
Where as CL type cannot flush away the contamination from the sealing surface because this seal is equipped with an additional third lip intended to keep the grease inside. The nature of the PTFE material makes it possible for the other two sealing lips to work effectively without lubrication. This makes the CL seal unique for bearing assemblies because it does not need to be regreased and therefore is maintenance-free.
Normal stresses in the grease, due to the high shear rates in the shaft area or in the seal contact area, generate a contact force on the seal lip. This is in addition to the lift generated by elastohydrodynamic lubrication. Because of the overall design of the seal, this lift effect will be limited. Therefore the PTFE lips fit more tightly and with more tension around the shaft. This makes it more difficult for dirt to get under the lip and wear a groove into the shaft.
Double protection
In grease-lubricated Extreme Bearings such as the CC seal, it is not only the small gap between the seal lip and the shaft that provides sealing against contaminants. The grease in between the sealing lips also provides a sealing action.