Features of ammonia stop valves
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Who can introduce the features of ammonia stop valves? Why are ordinary valves not suitable for ammonia media?
Ammonia has a strong corrosive effect; copper is generally not used as a material, but special bronze alloys can be employed, with WCB being the most common choice. Temperature requirements are also strict, especially in the case of liquid ammonia, which tends to leak. Therefore, ordinary balls are subjected to chemical treatments to prevent ammonia leakage (I’m not sure exactly how this is done). PTFE or 4F is used as the packing material
Thank you. :victory:
What was said on the 3rd floor is correct; let me add something more. Ammonia vaporizes very easily and has excellent permeability; therefore, the sealing of the valve stem and seat is specially designed, with the seat material being made of babbitt.
Do the valves for ammonia also take into account and counteract the impact of excessive temperature fluctuations during use on the materials? Does anyone know what adverse effects might occur if ordinary cast steel valves are used in ammonia pipelines where ammonia-related valves are intended?
Ordinary cast steel valves can also be used, but they have a shorter lifespan, mainly due to the tendency for internal leakage. We used ordinary globe valves with steel valve stems at one higher pressure rating, and the results were quite good. Use appropriate force to close the valve when in use.
In our workshop, there is an ammonia valve with the code JK41F-25 (SA). I’m not sure what K and SA mean; could someone with more knowledge please explain?
Copper is not the best material to use for ammonia systems