Propylene Glycol Resistant O-Rings
Compatibility ratings for 7 O-ring materials in Propylene Glycol service
Propylene Glycol (Fluids) 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 | A | excellent — recommended for continuous service |
| FKM | A | excellent — recommended for continuous service |
| EPDM | A | excellent — recommended for continuous service |
| VMQ | A | excellent — recommended for continuous service |
| PTFE | A | excellent — recommended for continuous service |
| FFKM | A | excellent — recommended for continuous service |
| HNBR | B | good — suitable for most applications |
Why These Ratings
- NBR (A) — documented strengths include “Water (up to 100C).”
- EPDM (A) — documented strengths include “Hot water and steam.”
- VMQ (A) — documented strengths include “Water and steam.”
- PTFE (A) — documented strengths include “Steam and hot water.”
- FFKM (A) — documented strengths include “Virtually all chemicals except molten alkali metals.”
FluidsService: Concentration & Temperature Notes
This category is defined by chemistry families, not viscosity. Glycol-based fluids (brake fluid, antifreeze glycols) belong to EPDM — NBR and FKM both rate D in glycol brake fluid. Phosphate esters (Skydrol) defeat NBR, FKM and HNBR alike; only EPDM, PTFE and FFKM rate A. Never assume 'hydraulic fluid' describes a single chemistry.
Recommended
- NBR O-rings (A)
- FKM O-rings (A)
- EPDM O-rings (A)
- VMQ O-rings (A)
- PTFE O-rings (A)
- FFKM O-rings (A)
Use With Caution
- HNBR O-rings (B)
Avoid
No material is rated D for this chemical.
Related Chemicals (Fluids)
Frequently Asked Questions
Is Propylene Glycol compatible with FKM (Viton) O-rings?
FKM is rated A for Propylene Glycol: 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 Propylene Glycol compatible with NBR (nitrile) O-rings?
NBR is rated A for Propylene Glycol: excellent — recommended for continuous service. 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 Propylene Glycol?
PTFE is rated A for Propylene Glycol: 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 Propylene Glycol?
NBR, FKM, EPDM, VMQ, PTFE, FFKM are rated A (excellent) for Propylene Glycol 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 Propylene Glycol?
EPDM is rated A for Propylene Glycol: excellent — recommended for continuous service. Always confirm the specific fluid concentration and temperature before specifying EPDM for this service.
Need O-Rings for Propylene Glycol Service?
Send us your fluid, concentration and temperature — our engineers will confirm the right compound. MOQ 1 piece.