Issue of valve material selection
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When valves require NACE treatment, what materials of valves cannot or do not need to undergo such treatment?
NACE seems to be some kind of corrosion protection certification
Check those anti-corrosion standards; the angle valves used for our gasified black water are made of Inconel 625
NACE treatment is required in sulfur-containing media; it is necessary for ordinary 304 and 316 grades as well
For valves related to process media containing hydrogen sulfide, those made of carbon steel must undergo NACE treatment; as for those made of stainless steel, I have consulted several manufacturers – such as Fisher – and they also require NACE treatment for their 304 and 316 materials. Other manufacturers have stated that they will carry out the necessary treatment in accordance with the requirements of the client and the design agency. I saw a SEI document; it was just for the basic design, and no NACE treatment was required for the stainless steel material.
It is essentially about resistance to hydrogen sulfide; the standard in use is NACE MR0175. Grades 304 and 316 generally do not require any treatment to meet these requirements, but carbon steel needs an additional treatment process to achieve the same level of resistance, namely NACE treatment
The analysis should primarily focus on the material in contact with the liquid, such as WCB, 300 series stainless steels, and martensitic steels. Control is achieved by considering aspects such as the chemical composition of the material, heat treatment, and processing requirements; NACE MR0175 can serve as a reference