Nitric Acid (68%) vs PVDF Compatibility
Verified chemical resistance rating (Safe for Continuous Industrial Service), thermal boundary limits (Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service), and material specification guide for PVDF exposed to Nitric Acid (68%) in Strong Oxidizing / Mineral Acid service.
Nitric Acid (68%) vs PVDF: A1-Excellent
Exposing PVDF to Nitric Acid (68%) (Formula: HNO3 (68% Azeotropic Concentrated), CAS: 7697-37-2) carries an official rating of A1-Excellent (Safe for Continuous Industrial Service). Maximum recommended thermal operating limit: Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service. Best Grade A alternative materials for continuous or high-temperature service: Stainless Steel, Viton, PTFE.
Technical Specifications and Operating Parameters
| Chemical Medium | Nitric Acid (68%) |
|---|---|
| Chemical Formula | HNO3 (68% Azeotropic Concentrated) |
| CAS Registry Number | 7697-37-2 |
| Chemical Functional Class | Strong Oxidizing / Mineral Acid |
| Wetted Material | PVDF |
| Official Resistance Rating | A1-Excellent (Grade A) |
| Engineering Service Verdict | Safe for Continuous Industrial Service |
| Max Temp and Concentration Limit | Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service |
| Best Grade A Alternatives | Stainless Steel, Viton, PTFE |
| Backtest and Audit Verification | Verified against Cole-Parmer, ISM, Graco & CP Lab Safety industrial chemical resistance charts. |
Nitric Acid (68%) Cross-Material Comparison Matrix (9 Materials)
Direct benchmark ratings across all 9 reference industrial materials for Nitric Acid (68%):
| Material Name | Compatibility Rating | Service Verdict | Temperature Limit | Datasheet |
|---|---|---|---|---|
| Buna-N | D-Severe Effect | Incompatible — Immediate Failure Risk | Not recommended at any temperature or concentration | Report |
| EPDM | D-Severe Effect | Incompatible — Immediate Failure Risk | Not recommended at any temperature or concentration | Report |
| HDPE | D-Severe Effect | Incompatible — Immediate Failure Risk | Not recommended at any temperature or concentration | Report |
| Polypropylene | D-Severe Effect | Incompatible — Immediate Failure Risk | Not recommended at any temperature or concentration | Report |
| PTFE | A-Excellent | Safe for Continuous Industrial Service | Ambient to elevated operating temperatures within standard material limits | Report |
| PVC | C1-Fair | Caution: Short-Term or Emergency Use Only | Short-term exposure only; avoid continuous pressurized service | Report |
| PVDF | A1-Excellent | Safe for Continuous Industrial Service | Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service | Report |
| Stainless Steel | A1-Excellent | Safe for Continuous Industrial Service | Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service | Report |
| Viton | A1-Excellent | Safe for Continuous Industrial Service | Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service | Report |
Chemical and Material Interaction Analysis
Engineering Compatibility Verdict
Nitric Acid (68%) vs PVDF: A1 – Excellent (No Effect up to 120°F / 49°C)
Summary Verdict: PVDF (Kynar® / Polyvinylidene Fluoride) is rated A1-Excellent (Safe for Continuous Industrial Service) when exposed to Nitric Acid (68%) (Formula: HNO3 (68% Azeotropic Concentrated), CAS: 7697-37-2). Approved for primary wetted components including continuous-duty piping, bulk storage tanks, pump manifolds, and static/dynamic seals.
Quick Engineering Specifications
| Chemical Media | Nitric Acid (68%) |
|---|---|
| Chemical Formula | HNO3 (68% Azeotropic Concentrated) |
| CAS Registry Number | 7697-37-2 |
| Chemical Classification | Strong Oxidizing / Mineral Acid |
| Wetted Material | PVDF (Kynar® / Polyvinylidene Fluoride) (High-Purity Semi-Crystalline Fluoropolymer) |
| Official Resistance Rating | A1 – Excellent (No Effect up to 120°F / 49°C) (Grade A) |
| Recommended Temperature Window | Up to 120°F (49°C) verified; up to material thermal limit in non-pressurized service (Material limit: -40°F to 280°F (-40°C to 138°C)) |
| Top Grade-A Alternatives | Stainless Steel, Viton, PTFE |
| Data Verification Status | Verified against Cole-Parmer, ISM, Graco & CP Lab Safety industrial chemical resistance charts. |
Chemical & Material Interaction Analysis
Nitric Acid (68%) is classified as a strong oxidizing / mineral acid (corrosive proton attack combined with strong oxidative potential). Used in chemical synthesis, metal pickling, pH neutralization, and industrial etching. When selecting wetted components for PVDF, engineers must account for both concentration-dependent chemical attack and thermal stress:
- Reaction & Failure Mechanism: Exhibits negligible weight change, zero surface crazing, and minimal dimensional swelling (<1%) across extended immersion testing.
- Material Profile (PVDF): Superior mechanical strength and abrasion resistance compared to PTFE, with exceptional resistance to halogens (wet/dry chlorine, bromine), strong acids, and oxidizers. However, attacked by strong polar aprotic solvents (acetone, MEK, DMF, DMSO, NMP), primary amines, and high-concentration caustic soda (NaOH >50%) which cause dehydrofluorination.
- Application Scope: Common wetted components include high-purity acid distribution lines, wet-bench chemical etching systems, bleach/halogen injection quills, and magnetic-drive pump heads.
Cross-Material Compatibility Comparison for Nitric Acid (68%)
To help you select the longest-lasting piping, valve lining, or O-ring seal for Nitric Acid (68%), the table below compares PVDF against 8 other common industrial engineering materials:
| Wetted Material | Compatibility Rating | Service Recommendation | Material Temp Range |
|---|---|---|---|
| Polypropylene (PP Homopolymer & Copolymer) | D-Severe Effect | Incompatible — Immediate Failure Risk | 32°F to 180°F (0°C to 82°C) |
| 316 / 304 Austenitic Stainless Steel | A1-Excellent | Safe for Continuous Industrial Service | -325°F to 800°F (-198°C to 426°C) |
| Viton® (FKM Fluoroelastomer) | A1-Excellent | Safe for Continuous Industrial Service | -15°F to 400°F (-26°C to 204°C) |
| PTFE (Teflon® / Polytetrafluoroethylene) | A-Excellent | Safe for Continuous Industrial Service | -328°F to 500°F (-200°C to 260°C) |
| EPDM (Ethylene Propylene Diene Monomer) | D-Severe Effect | Incompatible — Immediate Failure Risk | -60°F to 300°F (-51°C to 149°C) |
| PVC Type I (Unplasticized Polyvinyl Chloride / uPVC) | C1-Fair | Caution: Short-Term or Emergency Use Only | 32°F to 140°F (0°C to 60°C) |
| PVDF (Kynar® / Polyvinylidene Fluoride) (Current Page) | A1-Excellent | Safe for Continuous Industrial Service | -40°F to 280°F (-40°C to 138°C) |
| Buna-N (Nitrile / NBR Elastomer) | D-Severe Effect | Incompatible — Immediate Failure Risk | -40°F to 250°F (-40°C to 121°C) |
| HDPE (High-Density Polyethylene) | D-Severe Effect | Incompatible — Immediate Failure Risk | -60°F to 140°F (-51°C to 60°C) |
Frequently Asked Questions (FAQ)
Is PVDF compatible with Nitric Acid (68%)?
PVDF is rated A1-Excellent (Safe for Continuous Industrial Service) with Nitric Acid (68%) (Formula: HNO3 (68% Azeotropic Concentrated), CAS: 7697-37-2). Exhibits negligible weight change, zero surface crazing, and minimal dimensional swelling (<1%) across extended immersion testing. Approved for primary wetted components including continuous-duty piping, bulk storage tanks, pump manifolds, and static/dynamic seals.
What is the best alternative material for handling Nitric Acid (68%)?
If PVDF does not meet your temperature or pressure requirements for Nitric Acid (68%), the highest-rated Grade A alternatives are Stainless Steel, Viton, PTFE. Always verify O-ring elastomers and metallic fasteners separately before full-scale deployment.
Technical Engineering FAQs: Nitric Acid (68%) vs PVDF
Click any question below for chemical failure-mode specifics, thermal derating limits, and material selection rules: