Which section of a pipeline is most vulnerable to corrosion?

The buried section of a pipeline is most susceptible to corrosion due to several factors that are inherent to its environment. When pipelines are buried, they are often in contact with soil, which can contain moisture and a variety of corrosive substances such as salts and acids. The soil's chemical composition, along with electrolytic potential, can accelerate the corrosion process significantly.

Furthermore, when pipelines are underground, they can also be exposed to various conditions that promote corrosion, including anaerobic bacteria that can thrive without oxygen, leading to biogenic corrosion. Additionally, the inability to visually inspect the buried sections makes it difficult to detect early signs of corrosion, allowing it to progress undetected until potentially serious damage occurs.

In contrast, aboveground sections typically benefit from better accessibility for regular inspections and maintenance, making it easier to apply protective coatings or cathodic protection systems. Similarly, joint connections and valve installations, while potentially vulnerable, are usually located in areas where they can be monitored and maintained more easily. Therefore, the unique exposure and accessibility issues of the buried sections contribute to their heightened vulnerability to corrosion.