Characteristics and performance

The Hallite 661 polyurethane cushion seal for pneumatic applications is designed to cushion the stroke of the piston in pneumatic cylinders by acting as a non-return valve.

Near the end of the cylinder stroke the cushion spear enters the seal and pushes it against the radial housing wall to trap air between it and the piston decelerating the piston in the process. When pressure is applied to the system to return the piston, specially designed venting grooves allow pressure to pass over the Hallite 661 to the piston.

The Hallite 661 is manufactured in Hythane® 181, Hallite’s high-performance polyurethane, for easy installation, excellent low temperature performance, and long service life.

Product details

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Max pressure *

16 Bar

Temp range


Max speed


* Max pressure stated is dependant on the material variant selected. Please consult the datasheet for further information.

  • Recomended
  • Possible
  • Not suitable

* For fluid types marked as possible, please call our team of experts on +49 (0)40 73 47 48-0 to talk through your requirements and determine if this seal is the most suitable for your needs.

 Dynamic applicationStatic application
Fluids based on mineral oil  
AnyNot suitableNot suitable
Waterbased fluids  
HFA (5/95)Not suitableNot suitable
HFB (60/40 invert emulsion)Not suitableNot suitable
HFC (water glycol)Not suitableNot suitable
WaterNot suitableNot suitable
Other fluid types  
Air/NitrogenRecommendedNot suitable
HFD (Phosphate ester ARYL Type)Not suitableNot suitable
Synthetic esters (HEES, HFDU)Not suitableNot suitable