NCCER Pipeline Corrosion Control Practice Test

Galvanic anode banks are utilized in cathodic protection systems to protect pipelines from corrosion. The anodes, which are typically made from metals like zinc, magnesium, or aluminum, are placed in the ground and connected to the pipeline. Their primary function is to provide a continuous flow of electrons to the pipeline, thereby reducing its electrical potential relative to the surrounding earth.

When functioning correctly, the electrical potential of the pipeline is intentionally made negative in comparison to the surrounding earth. This negative potential is crucial because it prevents the flow of electrons from the earth to the pipeline, which would contribute to the corrosion process. By becoming more negative, the pipeline is effectively protected as it becomes less attractive to corrosive elements in the environment. Thus, the use of galvanic anode banks plays a vital role in maintaining this protective condition.

The other options reflect different potentials that do not align with the operational principle of galvanic anodes; a positive or neutral potential would not adequately protect the pipeline, and having the same polarity would not provide any corrosion protection at all. Therefore, negative electrical potential is essential for effective cathodic protection and corrosion mitigation.