The basic principle of sealing is straightforward – the flexible lip is held against the rotating part (usually the shaft) whilst the casing (or O.D.) is pressed into the housing or bore and holds the seal in place. The sealing lip needs some form of lubrication to avoid overheating and is usually energized by means of a garter spring.
As type C with dust lip
In the automotive industry, these gaskets are used extensively in engine components, such as the cylinder head gasket which separates the combustion chambers from the cooling system, preventing oil and coolant mixing. A faulty gasket here can result in engine overheating or failure, underscoring the importance of quality in their manufacture.
Table 5: The major special seals, their shapes, and their features
A wide range of sealing devices are used in various machines.
Sealing devices serve the following functions:
As type C with dust lip
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