Please help, regarding the problem of liquid ammonia medium valve
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Please ask for help. Regarding a valve whose conveying medium is pure ammonia, what is the appropriate material for the valve sealing surface? In addition, why does the stop valve have a W sealing surface only when the valve body is made of stainless steel?
This post was last edited by zhanyl628 on 2020-7-14 10:48. The sealing surface material of the special valve for liquid ammonia is generally PTFE or Babbitt alloy. The material W of the sealing surface of the stop valve refers to the same as the body, that is, no additional surfacing or other materials are needed. Specific reference: GB/T 26478-2011 Stop valve and lift check valve for ammonia. In addition, please refer to the pipe flange connection.:
W refers to the sealing surface of the main body. For hard-sealed valves, the sealing surface must be stainless steel, so it can only be represented by W when the valve body is stainless steel.
1. Valves for ammonia are generally soft-sealed and not easy to leak. 2. When the sealing surface of the stop valve is W, it represents the body seal and does not require surfacing. The valve body is made of carbon steel and is easy to rust, so it will not be used. It can only be made of stainless steel.