Biodiesel Resistant O-Rings
Compatibility ratings for 7 O-ring materials in Biodiesel service
Biodiesel (Fuels) compatibility with the seven most common O-ring elastomers, rated on the standard A/B/C/D scale: A = excellent, B = good, C = fair, D = not recommended. This data also appears in our interactive chemical compatibility chart and is available machine-readable at /api/chemicals.json.
| Material | Rating | Guidance |
|---|---|---|
| NBR | B | good — suitable for most applications |
| FKM | A | excellent — recommended for continuous service |
| EPDM | C | fair — conditional use, verify with testing |
| VMQ | B | good — suitable for most applications |
| PTFE | A | excellent — recommended for continuous service |
| FFKM | A | excellent — recommended for continuous service |
| HNBR | A | excellent — recommended for continuous service |
Why These Ratings
- FKM (A) — documented strengths include “Gasoline and diesel fuels.”
- EPDM (C) — documented weaknesses include “Hydrocarbon fuels.”
- PTFE (A) — documented strengths include “Fuels and oils.”
- FFKM (A) — documented strengths include “Fuels and oils.”
- HNBR (A) — documented strengths include “Gasoline and diesel fuels.”
FuelsService: Concentration & Temperature Notes
Aromatic content is the hidden variable in fuel service. Standard gasoline rates NBR at B in our data, but high-aromatic blends push NBR toward failure while FKM stays A. Diesel is consistently friendlier to NBR than gasoline (A versus B). Fuel plus heat is the real killer: under-hood fuel seals running continuously above +100°C belong in FKM or HNBR, not NBR.
Recommended
- FKM O-rings (A)
- PTFE O-rings (A)
- FFKM O-rings (A)
- HNBR O-rings (A)
Use With Caution
- NBR O-rings (B)
- EPDM O-rings (C)
- VMQ O-rings (B)
Avoid
No material is rated D for this chemical.
Related Chemicals (Fuels)
Frequently Asked Questions
Is Biodiesel compatible with FKM (Viton) O-rings?
FKM is rated A for Biodiesel: excellent — recommended for continuous service. Ratings are general guidelines; concentration, temperature and exposure time all affect real-world compatibility, so validate critical applications with ASTM D471 immersion testing.
Is Biodiesel compatible with NBR (nitrile) O-rings?
NBR is rated B for Biodiesel: good — suitable for most applications. NBR is the lowest-cost elastomer, so when it earns an A or B rating it is usually the economical default; when it rates C or D, do not substitute it for a higher-rated material to save cost.
Can I use PTFE O-rings with Biodiesel?
PTFE is rated A for Biodiesel: excellent — recommended for continuous service. Remember that PTFE has no elastic memory — in demanding service it needs spring energization or an elastomer core (FEP/PFA encapsulation) to maintain sealing force.
What is the best O-ring material for Biodiesel?
FKM, PTFE, FFKM, HNBR are rated A (excellent) for Biodiesel in our compatibility data and are the recommended starting point for material selection. Final selection should also account for operating temperature, pressure and whether the seal is static or dynamic.
Can I use EPDM O-rings with Biodiesel?
EPDM is rated C for Biodiesel: fair — conditional use, verify with testing. Always confirm the specific fluid concentration and temperature before specifying EPDM for this service.
Need O-Rings for Biodiesel Service?
Send us your fluid, concentration and temperature — our engineers will confirm the right compound. MOQ 1 piece.