Hallite 668 twin lip static seal is designed to seal the joint between the gland and the cylinder bore or between the rod and the piston. The sealing element is a very effective replacement for the conventional O-ring and back-up ring combination in heavy-duty applications.

The main advantage is its high groove stability compared to a conventional O-ring thus reducing fluid transfer caused by pumping.

Every nominal diameter of the Hallite 668 is suitable for a range of bore diameter, ØD₁ , or rod diameters, Ød₁.

The Hallite 668 is moulded in Hythane® 181, Hallite’s high-performance polyurethane, for easy installation and excellent low temperature performance.

The Hallite 668 is generally supplied as a bespoke part. Contact your local Hallite sales team for details.

  • Unit of measurement:
Unit of measurement:

Max pressure

500 Bar

Temp range

  • Recomended
  • Possible
  • Not Suitable

* For fluid types marked as possible, please call our team of experts on +44 208 941 2244 to talk through your requirements and determine if this seal is the most suitable for your needs.

  Dynamic application Static application
Fluids based on mineral oil    
Any Not suitable Recommended
Waterbased fluids    
HFA (5/95) Not suitable Recommended
HFB (60/40 invert emulsion) Not suitable Recommended
HFC (water glycol) Not suitable Possible
Water Not suitable Recommended
Other fluid types    
Air/Nitrogen Not suitable Recommended
HFD (Phosphate ester ARYL Type) Not suitable Not suitable
Synthetic esters (HEES, HFDU) Not suitable Recommended