Sulfuric Acid (Dilute) Resistant O-Rings
Compatibility ratings for 7 O-ring materials in Sulfuric Acid (Dilute) service
Sulfuric Acid (Dilute) (Acids) 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 | C | fair — conditional use, verify with testing |
| FKM | A | excellent — recommended for continuous service |
| EPDM | B | good — suitable for most applications |
| VMQ | C | fair — conditional use, verify with testing |
| PTFE | A | excellent — recommended for continuous service |
| FFKM | A | excellent — recommended for continuous service |
| HNBR | C | fair — conditional use, verify with testing |
Why These Ratings
- NBR (C) — documented weaknesses include “Strong acids.”
- FKM (A) — documented strengths include “Strong acids.”
- VMQ (C) — documented weaknesses include “Concentrated acids and alkalis.”
- PTFE (A) — documented strengths include “Strong oxidizing acids.”
- FFKM (A) — documented strengths include “Concentrated oxidising acids.”
- HNBR (C) — documented weaknesses include “Strong acids.”
AcidsService: Concentration & Temperature Notes
Concentration changes everything in acid service. In our own data, sulfuric acid shifts NBR from C (dilute) to D (concentrated) and EPDM from B to C as concentration rises. Oxidizing acids (nitric, concentrated sulfuric) attack the polymer backbone chemically rather than merely swelling it, which is why PTFE and FFKM dominate this category. Temperature accelerates acid attack sharply — a rating earned at room temperature may not hold at +60°C.
Recommended
- FKM O-rings (A)
- PTFE O-rings (A)
- FFKM O-rings (A)
Use With Caution
- NBR O-rings (C)
- EPDM O-rings (B)
- VMQ O-rings (C)
- HNBR O-rings (C)
Avoid
No material is rated D for this chemical.
Related Chemicals (Acids)
Frequently Asked Questions
Is Sulfuric Acid (Dilute) compatible with FKM (Viton) O-rings?
FKM is rated A for Sulfuric Acid (Dilute): 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 Sulfuric Acid (Dilute) compatible with NBR (nitrile) O-rings?
NBR is rated C for Sulfuric Acid (Dilute): fair — conditional use, verify with testing. 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 Sulfuric Acid (Dilute)?
PTFE is rated A for Sulfuric Acid (Dilute): 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 Sulfuric Acid (Dilute)?
FKM, PTFE, FFKM are rated A (excellent) for Sulfuric Acid (Dilute) 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 Sulfuric Acid (Dilute)?
EPDM is rated B for Sulfuric Acid (Dilute): good — suitable for most applications. Always confirm the specific fluid concentration and temperature before specifying EPDM for this service.
Need O-Rings for Sulfuric Acid (Dilute) Service?
Send us your fluid, concentration and temperature — our engineers will confirm the right compound. MOQ 1 piece.