Heavy-Duty Piston U-Cup Seal with Active Backup Ring

Series 227: Heavy-Duty Piston U-Cup Seal with Active Backup Ring

The 227 Series is a heavy duty polyurethane piston seal with a U-cup design and active backup ring. This pressure-relieving design is ideal for back-to-back tandem arrangements. The active backup ring allows larger clearances and higher pressures. The asymmetrical design of the U-cup seal allows maximum stability in the seal groove. It is an ideal choice when pressure trapping is a problem.



High pressure capability and wide temperature range

Pressure-relieving design prevents pressure trapping

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

Exceptional abrasion resistance


The 227 Series piston seal is typically used in heavy-duty applications, where pressure trapping, high pressure and large extrusion gaps exist.

Typical Applications

  • Steel and aluminum processing
  • Mobile Hydraulics
  • Hydraulic Cylinder Rebuild
  • Agricultural Hydraulics
  • Construction Equipment


The 227 Series piston seal features high-grade polyurethane. Standard materials are MP03 H-PU and polyacetal backup ring. 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 and PEEK.

Material Code
Polyurethane H-PU / POM MP30
Polyurethane TPU / POM MN30
Temperature MP03

hydraulic oil -20…+115 -5…+240
water oil emulsions (HFA) +5…+55 +40…+130
water-glycol fl uids (HFC) -20…+55 -5….+130
polyol esters (HFD) - -
water +5…+55 +40…+130
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.