U-Cups

A specialized rod seal design

Rod U-Cups SERIES 13 (INCH SIZES)

Characteristics

The RO. U-cup is a specialized rod seal design, developed from the standard Symmetrical U-cup. It assures improved sealing performance due to the following features:

  • Interference Fit in the Groove. The RO. U-cup has an OD. Larger than the groove for which it is intended. This insures a tight fit in the groove to prevent movement of the seal during cylinder operation. It also overcomes any problems with shrinkage and low temperature leakage.
  • Improved Lip Design. The static lip, being supported by full surface contact with the groove wall, has a comparatively thin cross section. This permits the dynamic sealing lip to have a heavier cross section for an improved high pressure capability. Also, the outer lip is longer, to give better stability during installation and protection the dynamic sealing lip. Both lips have precision knife trimmed chamfers to provide complete circumfrential lip contact.

Material:

  • TYPE: Unithane 292A, Liquid Cast Polyurethane.
  • HARDNESS: Durometer 92A
  • FLUID COMPATABILITY: See ‘Material Specifications’, Technical Bulletin US 96

Piston U-Cups SERIES 14 (INCH SIZES)

Characteristics

The PI. U-cup is a specialized piston seal design. Developed from the standard Symmetrical U-cup. It assures improved sealing performance due to the following features:

  • Interference fit in the groove. The PI. U-cup has an ID smaller than the groove for which it is intended. This insures a tight fit in the groove to prevent movement of the seal during cylinder operation. It also provides a sufficient preload condition to prevent interference with the cylinder wall due to thermal expansion of the seal at high operating temperatures.
  • Improved lip design. The static lip, being supported by full surface contact with the groove wall, has a comparatively thin cross section. This permits the dynamic sealing lip to have a heavier cross section for an improved high pressure capability. Also, the inner lip is longer, to give better stability during installation on a one piece piston and to protect the dynamic sealing lip. Both lips have precision knife trimmed chambers to provide complete circumferential lip contact.

Material:

  • TYPE: Unithane 292A, Liquid Cast Polyurethane.
  • HARDNESS: Durometer 92A
  • FLUID COMPATABILITY: See ‘Material Specification

Symmetrical U-Cups SERIES 15 (INCH SIZES)

Characteristics

The Symmetrical U-cup is a double chamfered U-ring seal manufactured from Unithane 292A liquid cast polyurethane. This material, which is used for many of our other products, is well known for its superior abrasion resistance, low compression set and resistance to extrusion.

The symmetrical configuration, with equal lip interference and equal heel clearance on both the inside and outside diameters, provides a seal which is capable of use in both rod and piston sealing applications. The sealing tips are knife trimmed to eliminate all moulding flash and to provide superior low pressure sealing performance.

These seals are available in a full range of standard sizes to fit most piston grooves and packing glands. Tooling is also available for a large range of special sizes.

Series 15 U-cups can be easily snapped into a groove or stretched over a one piece piston. Once installed they will immediately return to their original dimensions.

Material:

  • TYPE: Unithane 292A, Liquid Cast Polyurethane.
  • HARDNESS: Durometer 92A
  • FLUID COMPATABILITY: See ‘Material Specifications’, Technical Bulletin US 96

A.N. Type U-Cups SERIES 16 (INCH SIZES)

Characteristics

The A.N. Type U-cup is the original U-cup design and was previously manufactured from rubber. Our Series 16 seals are made from thermosetting liquid cast polyurethane, which delivers up to ten times the service life of neoprene rubber.

*note statement below refers to diagram, may not be on website!! This cross section of the A.N. Type seal has a symmetrical profile with considerably flexible lips. The lips are knife trimmed at 90 degrees to the seal axis. The lip design insures a lighter preload condition when the seal is installed. This, in turn, reduces friction and break out force.

A.N. Type U-cups are most suited to pneumatic and low pressure hydraulic use, in both rod and piston application.

Material:

  • TYPE: Unithane 292A, Liquid Cast Polyurethane.
  • HARDNESS: Durometer 92A
  • FLUID COMPATIBILITY: See ‘Material Specifications’. Technical Bulletin US 96