MEDIA GUIDE
Nitric Acid Valves
An oxidising acid — the passivation rules invert.
Oxidizing acid — stainless steels perform well; titanium also excellent. Avoid copper-bearing alloys and organics contamination.
Materials at a glance
| Material | Rating | Up to |
|---|---|---|
| Stainless steel 304 (ASTM A351 CF8) | Excellent | 80 °C |
| Stainless steel 316 (ASTM A351 CF8M) | Excellent | 80 °C |
| Duplex 2205 (ASTM A995 Gr.4A) | Excellent | 80 °C |
| Hastelloy C-276 (ASTM A494 CW6M) | Excellent | 90 °C |
| Titanium Gr.2 (ASTM B367 C2) | Excellent | 100 °C |
| PTFE/PFA-lined ductile iron | Excellent | 120 °C |
Ratings: Excellent / Good / Conditional / Not recommended, from this site's boundary-and-medium data set. The manufacturer's data sheet for the specific product governs.
What drives the choice
- Austenitic stainless is the standard answer; carbon steel is out
- Oxidising service excludes some alloys that milder acids allow
- Concentration band decides the material, not the word 'nitric'
Where the boundaries sit
- Fuming or mixed-acid variants leave the published rows
Related reading
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