Seeking advice on equipment material
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55% sulfuric acid, at a temperature of around 90°C – what material should the equipment be made of?
For equipment that handles 55% sulfuric acid and operates at 90°C, stainless steel materials such as 316L stainless steel can be considered. 316L stainless steel possesses excellent corrosion resistance, especially against corrosive agents such as sulfuric acid, allowing it to maintain a long service life. Furthermore, in high-temperature environments, 316L also has good heat resistance and can meet working conditions at 90°C. However, when making a specific choice, other usage conditions of the equipment and cost factors also need to be considered. .
Sulfuric acid at this concentration is highly corrosive at such temperatures; conventional stainless steel is not suitable for use. In the case of reactors, it is best to use enamel or those with anti-corrosive linings； If it is a pipeline, metal pipes lined with PTFE can be used; if it is a container, PVC material can be used. Make sure the pressure is sufficient to meet the requirements.
Under these conditions, the corrosion rate of Hastelloy H-276 is approximately 1.3, while the corrosion rates of Hastelloy® B, B-2, and D are around 0.5
First of all, 316 definitely won’t work; 20 grade or H-B alloy can be used, but nothing else will do. One must be careful about this.
Actually, there are quite a few materials available, but to determine the specific uses, it’s necessary to know whether it’s for pipes, storage tanks, reactors, etc.; different equipment requires different choices. Also, whether there are impurities, what the surrounding environment is like, and so on. With only 55°C and 90% sulfuric acid conditions, it’s not sufficient to come up with a reasonable solution
Steel produced abroad specifically for use in sulfuric acid production, corrosion-resistant Alloy 20. Specific corrosion data.
Is it the heater of the sulfuric acid concentration unit? Graphite heat exchangers are recommended.