FEP Coated "O" Rings

FEP [Fluorinated ethylene-propylene] is a thermoplastic material with properties similar to PTFE. O-rings which are seamlessly coated with FEP have an elastic core made from FPM or VMQ and are used if very high thermal or chem¬ical loads are present. The high chemical resistance of the coating protects the core against damage by the potentially aggressive medium.

FEP coated O-rings are used – similar to PTFE-rings – where the chemical resistance of the normal elastomer O-ring is no longer sufficient, but where a certain elasticity is needed. The elasticity is ensured by the inner ring and the chemical resis¬tance is achieved by the seamless FEP coating.

FEP coated O-rings are perfectly suited for the chemical and petrochemical sector, medical technology, food sector, water and waste water technology and similar industrial appli¬cations. A typical application for FEP coated O-rings is the sealing of valve stems and as a secondary sealing element for slow switching and rotary movements.


  • Very good chemical resistance against most liquids and chemicals
  • Temperature range from approx. –60 °C to 200 °C [depending on inner ring material]
  • No contamination of food, pharmaceutical or medical products
  • Physiologically harmless, can be sterilised
  • Sufficient elastic behaviour
  • FEP O-rings can be replaced with standard O-ring seals without limitation
  • No changes to the groove dimensions are necessary
  • The O-rings are less flexible than elastomer O-rings due to the FEP coating. They can only be stretched minimally and have a lower elasticity or a higher permanent deformation

Sealmax has now tied up with KWO and IDT Germany for marketing their product range in India