PTFE/FEP/FPA Coated O-Rings / Teflon Coated O-Ring Seals

PTFE seals can remain stable in high-temperature environments without deformation or failure, which is crucial for equipment operating under high temperatures. Additionally, they exhibit excellent corrosion resistance, protecting equipment from damage caused by various chemical substances.

Product Introduction:
Encapsulated seals (PTFE-encapsulated O-rings) combine the elasticity and sealing properties of rubber with the chemical resistance of Teflon. They consist of an inner core made of silicone or Viton rubber (fluororubber) and a relatively thin outer layer of Teflon FEP (fluorinated ethylene propylene) or Teflon PFA (perfluoroalkoxy). This rubber-Teflon seal offers exceptional sealing performance. Rubber O-rings are prone to wear, have poor chemical resistance and gas permeability, while pure O-rings, though harder and more compression-resistant, lack elasticity. The outer Teflon FEP/PFA layer provides excellent resistance to swelling and chemical stability (unless exposed to alkali metals, fluorine, and some halides at high temperatures). It maintains good elasticity near the rubber O-ring, with a very low friction coefficient (only 0.1–0.2) and outstanding gas permeability resistance. These properties make encapsulated seals suitable for harsh environments. Therefore, PTFE-encapsulated O-rings can replace expensive rubber O-rings.

Three types of outer plastic materials:
1. FEP (fluorinated ethylene propylene), temperature range: -20°C to 200°C, general-purpose;
2. PFA (perfluoroalkoxy), temperature range: -20°C to 260°C, high-temperature resistant;
3. Dual-layer PTFE, temperature range: -50°C to 260°C, specialized corrosion resistance;

Two main types of inner rubber materials:
1. Silicone rubber (SIL)
2. Fluororubber (FKM)
Other materials such as nitrile rubber (NBR) and ethylene propylene diene monomer (EPDM) require customization.

Compressibility:
The FEP outer layer provides excellent resistance to hardening and brittleness, while the silicone or Viton rubber inner core ensures that the seal maintains good elasticity even at temperatures up to 205°C.

Both encapsulated seals and Teflon-coated O-ring seals are further processed and treated based on PTFE. Encapsulated seals typically involve coating PTFE material onto a substrate of another material to enhance overall sealing performance and durability. Teflon coating, on the other hand, involves applying a layer of PTFE or other fluorinated materials to the surface of an O-ring seal to improve its corrosion and high-temperature resistance.

Due to factors such as seal size, material, quantity, and customization level, it is difficult to provide a specific price. However, generally speaking, PTFE seals are slightly more expensive than seals made of ordinary materials. Considering their excellent performance and durability, the price is well justified.