andygo11
Materials
- Feb 15, 2013
- 20
Hi, we have a produced water injection line into a desanding vessel. Outside the vessel, there are two control valves for the injection line. After a year, there are some pitting and general corrosion occurred downstream of the valves and in the valves. Based on our analysis, we think the pitting is caused by cavitation due to the cyclic pressure drop when closing the valve. Also, we found that, if we used a galvanized trim valve, after a year, there is no corrosion or pitting issue inside the valve. Still the bare carbon steel pipe downstream still has the issue. My question is why the galvanized coating can help the cavitation? I did some search on line. Usually, the hard materials can be an option to prevent the cavitation.