Which valve should be used at the junction of the two media
Thread Content
One side of the valve is liquid ammonia and the other side is steam – which type of valve should be used? We were previously using plug valves, but they often leaked, which was very dangerous. I would appreciate some advice from those with more experience
Gate valves and ball valves can meet the requirements
There should be no special requirements; I recommend using a ball valve
I would like to ask what the purpose is of these two substances meeting at this valve? It’s not to save material by using a single pipe, is it? It’s just like water pipes and steam pipes; if that’s the case, then the designers at the time should have taken the risks into consideration. The requirements for temperature and pressure for these two types of substances differ greatly, and it’s generally not advisable to design pipes that connect them. So I think it’s unlikely. Maybe you should ask the original designers?
Upstairs, intersections are quite normal; for example, steam purging lines, or lines related to crude oil processing such as the three-injection lines
It’s still not clear why liquid ammonia and steam come together If the pressure is not very high, ball valves are recommended. Gate valves can also be considered, but due to the high pressure, ball valves are the only option
I just think these two substances have very different requirements regarding temperature. If steam is used for purging, then a temporary connection is sufficient; there’s no need for a separate pipeline, and it would also be connected to liquid ammonia, which only adds unnecessary risk factors!
May I ask what the temperatures of the steam and liquid ammonia are? High-temperature ball valves can generally be considered; if the temperature is high and the temperature difference is large, valves with bellows can also be used.
As a supplement, it is designed for steam purging; due to the high frequency of purging required by the process, fixed pipes are not used instead temporary pipes are employed. The temperature of ammonia is generally 2 degrees, and sometimes around minus 5 degrees, while the temperature of the steam is 170 degrees. This post was last edited by YearRing on 2007-12-10 11:54.]
Ball valves are the best choice, as they offer better sealing performance than gate valves. It is also recommended to use track-type ball valves, given that liquid ammonia is prone to leakage.
Thank you all for your suggestions. I also tried ball valves, but the PTFE seals failed as soon as hot and cold media passed through them.
It is recommended that the poster consider the opinion of student 678 from Building 12#. If such a setup is necessary, a hard-sealed ball valve can be used.
Thank you all. I will take into account the suggestions from the 12th floor and go back to adjust the pipelines on site.