Heavy-Duty Accumulator Piston Seal

Series 263: Heavy-Duty Accumulator Piston Seal

The 263 series is one of the most robust five-piece piston seals available on the market. It consists of a profiled energizer, a PTFE-filled seal element, two active anti-extrusion backup rings and an elastomeric quad ring. It is designed for double-acting cylinders in heavy-duty applications subject to severe pressure spikes coupled with high running clearance. it offers zero-drift performance due to the elastomeric seal ring, which also makes it ideally suited for gas sealing applications.



Long service life under the harshest conditions

Compatible with water-based fluids

Optimized for high running clearance

Easy installation


The 263 series piston seal is ideal for sealing gaseous media or where zero cylinder drift is required.

Typical applications include:

  • Accumulators
  • Specialty high-pressure cylinders
  • Various advancing and secondary cylinders

The 263 series piston seal features custom blended PTFE-filled compounds that provide ultra-low friction and high-speed performance and minimal wear. The standard compounds are PTFE-filled with bronze filler or PTFE-fille with glass-moly. The 263 series features a robust elastomeric energizer with backup rings in a high strength thermoplastic. The temperature range of the seal can be increased by selecting an FPM energizer in place of the standard NBR energizer.

Material Code
PTFE-Bronze compound / NBR / Pom MT24
PTFE-Glass moly / NBR / POM MT84
Temperature MT24


hydraulic oil -30…+100 -22…+212 -30…+100 -22…+212
water oil emulsions (HFA) - - +5…+50 +40…+140
water-glycol fl uids (HFC) -. - -30…+60 -22…+140
water - –5…+100 +40…+212
Speed 5 m/s (16.5 ft/sec)
Pressure 400 bar (6000 psi)

Note: for other materials or fluids please contact our engineering department