Material issues with pipeline valves for concentrated hydrochloric acid
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This post was last edited by Valve Mingming on 2010-12-12 at 16:53. PVC-U is used for pipes carrying concentrated hydrochloric acid, and PVC-U valves are also employed. The packing used is rubber; the manual states that rubber can resist corrosion by hydrochloric acid. However, after 3 months, the sealing packing of the valve expanded and the valve ceased to function. Is this situation due to the fact that rubber packing cannot be used with hydrochloric acid? What valve should be used as a replacement?
NBR has limited resistance to hydrochloric acid; it will expand after being used for some time. I think diaphragm valves and plug valves can be used for small-diameter applications, while corrosion-resistant butterfly valves are suitable for large-diameter ones. This is just my personal opinion, for reference only!
What was said upstairs makes sense. I think that with highly concentrated hydrochloric acid, rubber cannot withstand the corrosion – could it be that the initial selection was incorrect?!
It is extremely corrosive! It is recommended to use Monel alloy; 2205 is also an option. Some users choose PTFE lining, but none of these options are particularly ideal