The Hallite 58 double acting piston seal combines the Hallite 56 seal with bearing rings to give a very robust heavy duty seal assembly for split pistons. It enables the designer to use large clearances and, with the integral bearing rings, to restrict the piston length.

The assembly comprises a seal and two L shaped bearings. The centre of the seal is rubber which is bonded to two ‘U’ section bases of rubberised fabric, and is compressed by the housing to obtain an effective low pressure seal. When the pressure increases the rubber energises the ‘U’ section and deforms it to the housing, increasingthe sealing area and improving the seal.

Rubberised fabric is used to protect the rubber, because it has strength and durability which combines with its ability to retain lubricant to help keep friction low and reduce wear.

Supporting the seal at either end is a polyacetal bearing proportioned to react to the pressure on the seal to prevent extrusion damage, and support the piston in its side load.

  • Unit of measurement:
Unit of measurement:

Max pressure

700 Bar

Temp range


Max speed

  • 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 Recommended
HFB (60/40 invert emulsion) Recommended Recommended
HFC (water glycol) Recommended Recommended
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