Anti-static grounding of overhead pipelines and corrosion issues
Thread Content
I’m seeking advice from experts: I’ve been struggling with one issue. The external surfaces of the pipes need to be painted for corrosion protection, and since the pipeline system has anti-static requirements, grounding wires are used to connect the flanges; these wires are then connected either to a copper busbar or directly to the grounding grid system； So here’s the question: If that’s the case, doesn’t it mean that the piping system is grounded? And wouldn’t that lead to electrochemical corrosion? What’s the difference from directly buried pipes? There is a speculation, though it’s not certain whether it’s correct: perhaps the reason why the potential of the grounding grid and the grounding wires differs from that of the pipeline system is that, in effect, the grounding grid acts as a sacrificial anode to provide cathodic protection for the pipeline system Otherwise, I really can’t figure it out. Seeking advice, thanks!
That’s a tough question, but it has indeed always been done that way.
The corrosion of buried pipes is electrochemical corrosion caused by the soil, while overhead pipes do not come into direct contact with the soil, so their corrosion mechanisms are different.
Even after the pipeline system on the pipe rack is grounded, there is no potential difference or electrolyte, so electrochemical corrosion still does not occur.
Electrochemical corrosion occurs when a buried grounding wire (metal) comes into contact with the soil (an electrolyte solution)~~ It is recommended to learn about the concept of electrochemical corrosion and the factors that lead to its occurrence~~
It’s a piping system; the potential throughout the entire system is the same. If you ground it, think about it – there must be a potential difference, and therefore electrolyte will form. Maybe it only corrodes the grounding system?
That makes sense; I’ll take another closer look! ! Thank you
Haha； I finally understand ； Thank you all; I now have a better understanding of cathodic protection methods such as sacrificial anodes and forced current application! Thank you all!
Grounding of overhead pipelines does not cause electrochemical corrosion; electrochemical corrosion requires a circuit, and the pipeline and ground cannot form such a circuit through the atmosphere. This risk exists if the pipeline has buried sections.