I would like to ask: for gate valves using liquid ammonia as the medium, is it acceptable to use STL for the sealing surface?
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I would like to ask: for gate valves operating in liquid ammonia media, is Stellite STL suitable as the sealing surface material? I appreciate any guidance you can provide
Gate valves are not recommended for use with liquid ammonia media
I completely agree, but since the customer wants to use it, there’s nothing I can do. I originally planned to use all 304 material, but then the customer requested STL. As far as I remember, STL doesn’t offer any advantages for liquid ammonia, so I’m seeking advice from everyone here
The customer insisted on using gate valves; we recommended bellows-type gate valves, as otherwise leaks are likely to occur at the valve stem. Liquid ammonia is a highly hazardous chemical, and any leakage can easily lead to accidents.
Liquid ammonia generally uses globe valves, with sealing surfaces made of babbitt or PTFE; STL alloy has also been used in some cases