In a sodium hydroxide solution with a pH of around 13, there is also sodium chloride present (6,000 PPM of chloride ions). The temperature is 110 degrees. What material should be chosen?
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In a sodium hydroxide solution with a pH of around 13, there is also sodium chloride present (6,000 PPM of chloride ions). The temperature is 110 degrees. What material should be chosen? Is titanium material okay? In a sodium hydroxide solution with a pH of around 13, there is also sodium chloride present (24,000 PPM of chloride ions). The temperature is 80 degrees. What material should be chosen?
Try conducting corrosion tests on various materials!
There are two theories regarding this issue. One is that chloride ions mask the corrosive effects in alkaline solutions; thus, only the corrosion caused by the alkaline solution needs to be considered； The other case is that the corrosiveness of chloride ions remains strong in alkaline solutions; in this case, both the corrosion caused by the alkaline solution and that caused by chloride ions must be considered. The riskiest minimum material: 316L, with chloride corrosion assumed to be shielded. Intermediate consideration materials: 2205 or 2507 or 254SMO. The safest materials: lining or titanium.
The 4th floor is the right choice. The 2205 is cheaper, but be prepared for maintenance work. If budget isn’t a concern, go for titanium instead
6000 ppm is approximately 0.06 g/L, and the pH level remains at 13. The chloride ions are present mainly in the form of NaCl. 304 stainless steel is sufficient for this purpose; if budget allows, one can opt for 316 or titanium-lined steel instead.
The worst choice is 2205; using titanium is the best option. 316L is similar to 304; it simply cannot resist chloride ion corrosion. At our company, all of the 316L valves had to be replaced within half a year; the equipment has been rewelded numerous times
Use fluorine lining; it’s best to conduct some experiments to see