Rod U-Cup Seal with Integrated Backup Ring

Series 139: Rod U-Cup Seal with Integrated Backup Ring

The 139 Series U-cup seal is a high-performance U-cup seal for use in high-clearance applications, typically in moderate to high-pressure environments. Its asymmetrical design ensures that the seal lip forces are optimized for every cross section and diameter. The integrated backup ring supports the seal and ensures maximum extrusion resistance in a larger than normal clearance application. Manufactured in a variety of materials and sizes from 6 mm to 2100 mm in diameter in standard or custom sizes.



Designed specifically for large clearance applications

High pressure capability and wide temperature range

Excellent fluid compatibility including water-based fluids (H-PU)

Exceptional abrasion resistance

Highly extrusion resistant

Available in diameters up to 2100 mm


The 139 Series U-cup seal is typically used in high-clearance applications as a primary seal and functions well in moderate to high pressures.

Typical Applications

  • Forging and extrusion presses
  • Stamping presses
  • Mining
  • Agriculture
  • Construction equipment
  • Injection molding machines

The 139 Series rod seal features high-grade polyurethane. Standard materials are MP03 machined H-PU, available up to 2100 mm in diameter, and MP50 injection-molded TPU. To suit a variety of applications the series is also available in NBR, H-NBR, EPDM and high temperature-resistant FPM. The backup ring materials include POM, Polyamide and PEEK.

Material Code
Polyurethane H-PU MP03
Polyurethane TPU MP50

Temperature MP03


hydraulic oil -20…+115 -5…+240 -30…+110 -20…+230
water oil emulsions (HFA) +5…+55 +40…+130 +5…+50 +40…+120
water-glycol fl uids (HFC) -20…+55 -5….+130 -30…+40 -20…+100
polyol esters (HFD) - - - -
water +5…+55 +40…+130 +5…+50 +40…+120
Speed 0.5 m/s (1.6 ft/sec)
Pressure 400 bar (6000 psi)

Note: for other materials or fluids please contact our engineering department.