Why are stop valves used in acetic acid plants as plug valves instead of ball valves?
Thread Content
Why are stop valves used in acetic acid plants as plug valves instead of ball valves? Is it mainly because of the high price of special material ball valves?
As far as I know, plug valves are more expensive than ball valves (for the same material, pressure rating, and diameter, they are roughly 20% more costly); as for valves made from special materials, I believe plug valves will be even more expensive. As for why a plug valve or a ball valve is chosen, it may be due to the following reasons: 1. Requirements specific to the type of piping; 2. Requirements from the client; 3. The experience of the instrumentation team at the design institute... Theoretically, ball valves evolved from plugs, and as for the differences between the two, one can look it up on Baidu
In a ball valve, isn’t there any cavity between the plug and the valve body, so no residue remains?……
Choosing a plug valve for an automatically controlled shut-off valve makes no sense, and the standards do not support it either. Is it a manual valve for the process?
Regarding acetic acid, there seems to be no difference between using ball valves and plug valves; there is no strict requirement to use plug valves. This likely depends on the selection preferences of the design institute and the usage habits of the customers.
Manual valves in acetic acid plants generally use plug valves, especially in the acetic acid carbonylation system. The main reason is the strong corrosiveness of the liquids in the acetic acid synthesis system and the high temperatures. The difference between a plug valve and a ball valve is that a ball valve has residual liquid left in its cavity, while a plug valve does not. If ball valves are used, their failure rate, maintenance frequency, and replacement needs are high; that’s probably why cut-off valves are chosen as well.
The plug body of a plug valve also has holes; similar to ball valves, liquid remains inside a ball valve when it is closed, but is this not the case with plug valves?
You can take a look at the structural descriptions of plug valves and ball valves.
Are plug valves more expensive than ball valves? It’s unreasonable to be so expensive
Yes, plug valves are more expensive than ball valves, and ball valves evolved from plug valves.