APG Hydraulic Seals Catalog

U-Cups
www.callapg.com 713-675-5271 FAX 713-675-2730
1-800-888-5223 FAX 1-800-444-3252
U-Cups derive their name from their shape and are self-sealing on both the inside diameter and outside diameter. They
are most often used for sealing rams or rods and are very popular due to the small gland space required. They are especially
adapted to low speed, low pressure environments for both pnuematic and hydraulic cylinders. They provide an
extremely smooth, steady movement because of their inherent low friction.
The seal is obtained by means of the flared, flexible lips coming in contact with the rod or cylinder wall. Clearance is provided
at the heel for minimum friction. Through this design, the packing is preloaded when installed. Sealing effectiveness
is increased by internal pressure of the air or fluid against the inner surface of the lips. For continued sealing effectiveness
and long seal life, the surface finish of the working surface of either rods or bores should be a maximum of 16 microinches.
It is not recommended that U-cups or any other single lip seal be used in any application where there is excessive
side loading.
8400 Series
The 8400 Series U-Cup has a chamfered lip and is available at
APG in 80 Durometer Nitrile.
6226 Series
The 6226 Series U-Cup has a flat sealing lip and is available at
APG in 70 Durometer Nitrile.
L9000 Series (Metric)
The Metric L9000 Series U-Cup has a chamfered lip and is available
at APG in 94 Durometer Urethane. The symmetrical section
allows the L9000 U-Cup to be employed as a rod or piston seal.
In addition to the products in this catalog,
APG supplies o-rings, industrial hose
couplings, industrial glass, and much,
much more! See pages 88 and 89.
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