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South Bend, IN 360001


T-Lon Solutions

POC Series O-ring Cap Piston Seal

The POC piston seal is a proven reliable seal for both low and medium pressure systems. They are designed to fit in standard o-ring glands for easy upgradable seals.

The POC seal is a low profile doubleacting filled T-LON® PTFE compound with an o-ring elastomer energizer designed for reciprocating or slow rotary applications with lower seal drag than O-ring/elastomer seals. The filled PTFE seal ring is manufactured with an interference fit with the bore and optimum compression with the O-ring energizer. This offers excellent sealability at low pressures and high pressures when the cylinder experiences ballooning. Since the energizers are standard AS568 O-ring sizes, many elastomer compounds are readily available.

Face Grooves (Optional):

For applications with high pressure rise rates, pressure spikes, and rapid change of direction, the seal is apt to experience blow-by. To prevent blow-by and to energize the seal rapidly, face grooves are added to both sides of the seal.


  • Low seal drag/friction (Minimize energy loss)
  • No Stick-slip (Smooth Operation)
  • Long seal life from T-LON® filled PTFE compounds
  • Available for cylinders up to 20″ diameter 


  • Mobile Hydraulic Cylinders
  • Pneumatic Piston Cylinders
  • Agriculture Equipment
  • Hydraulic Valves and Pumps
  • Static O-ring Glands (Prevents o-ring spiraling, Reduces friction/seal drag during assembly/disassembly)

Technical Data:

(1) T-LON® seal compound determines allowable pressure and velocity ranges
  • Velocity: Up to 12 ft/s
  • Pressure: Up to 5000 psi (Function of e-gap and T-LON® compound. Max velocity and pressure cannot be used together)

Most Common:


  • Good wear resistance for tubes with rougher surface finish
  • Chemical resistant and low seal drag


  • Good wear resistance with lubricating additive
  • Very low seal drag and low abrasiveness
(2) Loader compound determines temperature and chemical compatibility

Most Common:

NBR SHORE 70 A (“P”)

  • Working Temp. Range -30°F to 230°F (250°F intermittent)
  • Commonly used with greases, aliphatic hydrocarbon mineral and vegetable oils, and various hydraulic fluids


  • Working Temp. Range -50°F to 300°F (400°F steam intermittent)
  • Commonly used with water, steam, water/ silicone/ glycol based fluids, and app’s affected by ozone and weathering.
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Have questions? Our team is ready to help with anything you need. Feel free to reach out.

Contact T-Lon 888.340.TLON