U-cup seals are a form of lip seal which can be used in both dynamic and static applications. Their name derives from the distinctive U shape of their cross-section. They provide an extremely secure seal by using the increasing pressure of the application to energise the sealing lips. From this ingenious principle, a variety of unique configurations has been developed, each type designed for its suitability in specific uses.

Homogenous U-cups are ideal where a low friction seal is required as in most pneumatic applications. A Z-seal U-cup is a kind of squeeze seal which will create its own sealing force in low-pressure environments. A spring energised U-cup is made of plastic with a metallic spring that loads the lips of the seal to the hardware. The resultant seal compensates for the movement in dynamic applications. Unloaded urethane U-cups are heavy duty seals for use with both rods and pistons.

Loaded U-cups are intended for dynamic reciprocating applications and are particularly effective in low-pressure and piston systems. As the pressure on the U-cup increases, so does the strength of the seal. They perform a tight barrier against the escape of oil and grease as well as keeping out external contaminants and foreign matter. They are especially hard-wearing and provide exceptional resistance to most chemicals and to petroleum-based fuels such as petrol, diesel and liquefied petroleum gas (LPG).

When selecting the right U-cup seal, it is important to consider the optimum design elements for your needs. Check the chemical compatibility of seals, their minimum and maximum operating temperatures, the level of pressure to which they will be subjected, the amount of friction, their life expectancy and ease of installation.

At Simply Bearings we carry extensive stocks of U-cup seals for a variety of applications. One of our most popular items are loaded U-cup seals with B Lips, which are available in packs of 2, 5 or 10. EU-rated as economy quality, they are effective, long-lasting and affordable. We offer free delivery on any order over ?5, with same day and next day options available. Please contact us for delivery prices. Our 100% refund guarantee gives you 90 days to return unwanted or unsuitable items. Ordering from Simply Bearings could not be easier.