PTFE Coated O-Rings by Puja Seals in Pune, India – ideal for high-temperature, chemical-resistant sealing in industrial, pharma, and food-grade applications. PTFE-coated O-rings have the elastic and resilient core of a rubber O-ring (usually Viton or Silicone) with an exceptionally thin layer of low friction and chemically resistant Polytetrafluoroethylene( PTFE) coating.