Lip Selection

Lip style is directly related to the media type, shaft speed, pressure, temperature and contamination parameters. The media type discussed in the application study was grease versus oil retention. Other types of media include water, food and dairy products. All of these will affect the choice of available styles. Shaft speed, temperature and pressure parameters should all be reviewed in the parameter section to reveal their affect on sealing.

The table below shows common lip styles and their names, applications and descriptions. There are many other available lip styles when trying to accommodate special parameters or extreme environments.

The effectiveness of your radial shaft seal depends on the lip type selection. This is the most important design variable and will determine both the life expectancy and cost.

Application	Lip Type	Description
Oil retention	Standard “S” Lip	This style of lip is used for standard pressure oil sealing in clean environments. May be reversed for extreme grease sealing.
Oil retention for medium pressure applications	Standard “SN” Lip	This style of lip has a shortened flex section to accomodate medium pressures.
Oil retention for dusty applications	Standard “T” Lip	This style of lip is used for standard pressure oil sealing in dusty / dirty environments.
Oil retention for medium pressure applications	Standard “TN” Lip	This style of lip has a shortened flex section to accomodate medium pressures.
Grease retention applications	Standard “V” Lip	This style of lip is used for standard pressure grease sealing in clean environments. May be reversed to purge grease cavity.
Grease retension for dusty applications	Standard “K” Lip	This style of lip is used for standard pressure grease sealing in dusty / dirty environments.
Oil retention for applications with low lubrication	Standard “X” Lip	This style of lip is used for standard pressure sealing of none lubricating fluids. Inverted dust lip retains grease near sealing lip.
Separating two fluids	Standard “D” Lip	This style of lip is used for standard pressure separation of two fluid.
Grease retention in heavy contamination environment	Standand “U” Lip	This style of lip is used for standard pressure grease sealing in extreme / heavy contamination environments. Flexible lips allow for purging of grease cavity from either direction.
Grease retention in heavy contamination environment	Standand “T9” Lip	This style of lip is used for standard pressure grease sealing in extreme / heavy contamination environments. Lip on outside face is designed to act as an axial face seal.
Contamination exclusion	Standand “WP” Lip	This style of lip is used for scraping and wiping in hydraulic and pnuematic cylinder applications.