Material selection for valves in ammonia systems
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Are there any special requirements for the material selection of valves in the ammonia refrigeration system of an ammonia synthesis plant? The minimum temperature is -30 degrees Celsius; can valves made of carbon steel meet this requirement?
Carbon steel valves are generally not suitable; valves are usually made of stainless steel. In fact, for valves and pipes in low-temperature systems, carbon steel is hardly used at all, and stainless steel materials are typically chosen instead
Reply to 2# diwu0205: But we need to take cost factors into consideration. Everyone wants to use stainless steel, but carbon steel can also withstand temperatures as low as around -20 degrees, which is generally sufficient. Moreover, our old system has always used carbon steel; if we don’t replace everything, could the addition of stainless steel accelerate the electrochemical corrosion of the carbon steel components?
This post was last edited by diwu0205 on 2011-1-10 at 16:47. Reply to 3# lihudi: It’s worth making this investment to ensure the stable operation of the equipment. Corrosion will not occur just by replacing the valve, as valves with flange connections can be used