The Hallite 780 double-acting piston seal in a robust five part assembly is designed specifically for one piece pistons in a wide range of medium duty applications. The seal is also suitable for two piece pistons.

The Hallite 780 is comprised of a nitrile rubber sealing element, two split support rings, and two split L-shaped bearings located either side of the seal. The well proven nitrile rubber sealing element is designed to be extremely wear resistant with multi-lips for efficient dynamic sealing with minimal low pressure friction and, when pressurized, will be protected from extrusion damage by the extending lips of the support rings.

The support ring is manufactured from a tough, flexible, wear resistant thermoplastic polyester elastomer (TPE) and scarf cut for assembly.

Both the L-shaped bearings and support rings are grooved to ensure that the fluid pressure properly energises the sealing element and to prevent the possibility of any pressure trapping within the seal assembly.

  • Unit of measurement:
Unit of measurement:

Max pressure

400 Bar

Temp range


Max speed

  • Recomended
  • Possible
  • Not Suitable

* For fluid types marked as possible, please call our team of experts on (02) 9620 7300 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 Possible
Waterbased fluids    
HFA (5/95) Possible Possible
HFB (60/40 invert emulsion) Possible Possible
HFC (water glycol) Not suitable Not suitable
Water Possible Possible
Other fluid types    
Air/Nitrogen Not suitable Possible
HFD (Phosphate ester ARYL Type) Not suitable Not suitable
Synthetic esters (HEES, HFDU) Possible Possible