Automotive Powertrain Sealing | Engine/Transmission/Fuel NBR/HNBR/FKM
O-ring solutions for engines, transmissions, fuel and cooling systems—focus on fuel/oil resistance, high temp, fatigue, and anti-extrusion. Materials: NBR, HNBR, FKM, PTFE supports.
Automotive Sealing Overview
Needs: fuel/oil resistance, high temp, anti-extrusion, fatigue resistance for engine bay, transmission, fuel and cooling circuits.
Materials: NBR (economy fuel/oil, better low temp), HNBR (hot oil + wear), FKM (high temp + fuel/ATF chem), PTFE backups/encapsulated for low friction anti-extrusion.
Engine Sealing
- Oil/fuel contact: choose NBR/HNBR/FKM by temperature and fuel chemistry.
- High-temp areas (turbo/exhaust proximity): FKM + controlled gaps, add backups.
- Cooling circuits: EPDM/Silicone for coolant/low temp, avoid fuel exposure.
Transmission / ATF
- ATF prefers FKM/HNBR; watch temp cycling and squeeze/hardness choice.
- Dynamic spots: PTFE low-friction support to reduce wear/leaks.
- Surface finish/chamfer control; lubricate on install to avoid nicking.
Fuel System / EV Thermal
- Gasoline/diesel: NBR (better low temp) or FKM (high temp + additives).
- Alcohol/additive fuels: prefer FKM; confirm compatibility when in doubt.
- EV cooling/thermal: EPDM/Silicone for coolant/low temp; keep away from fuels.
Sizes & Customization
- AS568, metric, custom shapes; hardness 70/80/90A; color/labels for traceability.
- Backup rings/encapsulated options to boost extrusion and wear resistance; dynamic spots use low-friction PTFE.
Installation & Selection Tips
- Squeeze: static 15–25%, dynamic 10–20%; high pressure → higher hardness + backups.
- Avoid fuel on EPDM/Silicone; fuel/oil prefer NBR/HNBR/FKM.
- Cold start/low temp: NBR/Silicone stay softer; high-temp zones use FKM/HNBR.