Quick Answer
Fuel-vapor control components require very low transmission, stable sealing and resistance to fuel blends over long service periods.
Engineering requirements
- Fuel-vapor permeability
- Gas barrier behavior
- Fuel and ethanol-blend exposure
- Compression and sealing retention
- Temperature cycling
Recommended material families
| Material | Role / reason |
|---|---|
| CO | Strong barrier-oriented epichlorohydrin pathway. |
| ECO | Balanced barrier/flexibility pathway. |
| GECO | Useful where dynamic sealing and cure behavior are also important. |
Why material selection matters
The polymer family is only one part of permeation control; wall thickness, multilayer design, reinforcement and interface adhesion also matter.
What to confirm before selecting a grade
- Not necessarily. CO may improve barrier performance but flexibility, processing and low-temperature requirements can make ECO/GECO more suitable.
- No. Ethanol content, additives, temperature and test duration can materially change results.
Application note: The final elastomer and compound must be validated in the actual medium, temperature, pressure, dynamic condition and regulatory environment. Published generic resistance rankings are screening tools, not a substitute for application testing.