Fluorinated ethylene propylene, or FEP, is slightly different to PTFE, though it still has some of the same qualities:
- It is softer than PTFE and melts at a lower temperature, so extremely high temperatures may not be suitable.
- It is highly transparent, so whatever it covers will remain the same colour.
- It is resistant to sunlight, so it is good for all weather applications
FEP-encapsulated O-rings have a core of elastomer that is completely covered with a thin layer of the material. The elastomer core is either fluorocarbon (FKM) or silicone (VMQ) and can come in round, hollow or square section.
An encapsulated O-ring is often recommended in certain circumstances:
- A standard O-ring has poor chemical resistance for a desired application
- A solid PTFE O-ring does not offer sufficient softness for the application
Encapsulated O-Rings are commonly used in the food, pharmaceutical and chemical industries, and others where high chemical resistance and/or hygiene are required. They are better suited to static applications, however they can be used in a dynamic applications if the movement is slow and short. Tough this will reduce the lifetime of the seal.
The benefits of FEP encapsulated O-rings are:
- Good elasticity compared to PTFE
- Extremely low friction with a wide range of materials
- Temperature ranges of:
-60°C to +200°C with silicone (VMQ) core
-20°C to +200°C with fluorocarbon (FKM) core
- Resistance to a wide range of media
If you need to discuss your requirements please get in touch