MEDIA GUIDE
Seawater Valves
Chloride pitting is the governing risk — 316L is marginal.
Chloride pitting/crevice corrosion is the governing risk; 316L is marginal, duplex or titanium preferred for continuous duty.
Materials at a glance
| Material | Rating | Up to |
|---|---|---|
| Stainless steel 304 (ASTM A351 CF8) | Not recommended | — |
| Stainless steel 316 (ASTM A351 CF8M) | Conditional | 35 °C |
| Duplex 2205 (ASTM A995 Gr.4A) | Excellent | 60 °C |
| Titanium Gr.2 (ASTM B367 C2) | Excellent | 120 °C |
| PTFE/PFA-lined ductile iron | Excellent | 150 °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
- 316 stainless is only conditional; duplex or titanium is preferred for continuous duty
- Lined valves extend the temperature window
- Crevice corrosion at flanged joints belongs in the specification
Where the boundaries sit
- Continuous-duty seawater at temperature goes to a materials conversation, not a catalogue row
Related reading
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