Characteristics and performance

This twin lip, asymmetric, single-acting piston seal with precision trimmed sealing lips provides a dry sealing solution in light and medium-duty application. The sealing lips are trimmed at an angle to give optimal rod sealing performance.

Designed to have an interference on the piston spigot diameter and has a secondary lip, the secondary sealing lip located behind the primary sealing lip improves stability of the seal in the piston. The outer dynamic lip is shorter and more robust to improving sealing and compression set characteristics over conventional, symmetrical U-rings.

The Hallite 659 is moulded in Hythane® 181, Hallite’s high-performance polyurethane, for easy installation and excellent low temperature performance. Depending on tube bore finish, the Hallite 659 is also offered in Hythane® 361 polyurethane.

Product details

Ask an expert

Max pressure *

400 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 +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 Recommended Recommended
Waterbased fluids    
HFA (5/95) Possible Possible
HFB (60/40 invert emulsion) Recommended Recommended
HFC (water glycol) Possible Possible
Water Possible Possible
Other fluid types    
Air/Nitrogen Possible Possible
HFD (Phosphate ester ARYL Type) Not suitable Not suitable
Synthetic esters (HEES, HFDU) Recommended Possible