Which type of system is often used to prevent corrosion in pipelines?

The cathodic protection system is a widely recognized method used to prevent corrosion in pipelines. This system functions by reducing the corrosion potential of the metal surface that is being protected, usually through the introduction of a more electrochemically active metal. In practice, this is often achieved by attaching sacrificial anodes made from metals such as zinc or magnesium to the pipeline. These anodes corrode preferentially, thereby protecting the pipeline from corrosion.

In addition to sacrificial anodes, there are impressed current systems that utilize a direct current to create a protective electrochemical environment. This method allows for more control over the level of protection and can be used in more demanding applications.

Passive systems and fluid flow systems do not specifically target corrosion prevention in the same direct way that cathodic protection does. While passive systems may provide some level of resistance to corrosion, they do not actively mitigate corrosion like cathodic protection does. Similarly, fluid flow systems refer more to the mechanics of transporting fluids and do not inherently offer mechanisms to prevent corrosion in the materials that constitute the pipeline.