Which components are typically included in factory-installed galvanic cathodic protection systems for underground petroleum tanks?

Factory-installed galvanic cathodic protection systems for underground petroleum tanks are designed to prevent corrosion, which is a significant concern for metal components that are buried underground. One effective method of cathodic protection involves using corrosion-resistant coatings in conjunction with sacrificial anodes made from a more reactive metal, such as zinc.

The inclusion of corrosion-resistant coatings serves to provide an initial layer of protection against the corrosive environment, while zinc anodes function by corroding preferentially before the tank itself, thereby sacrificing themselves to protect the tank. This combination effectively inhibits the electrochemical processes that lead to corrosion.

The other options do not represent typical components of galvanic cathodic protection systems. For instance, plastic casing and insulation may be used in other contexts but do not directly involve the cathodic protection mechanism. Glass fiber supports and aluminum anodes are not standard for galvanic systems, as aluminum does not provide the sacrificial benefit required for the protection method being discussed. Similarly, a wooden frame and plastic fittings would not provide the necessary protection against corrosion.

Therefore, the correct choice reflects a well-established approach to protecting underground petroleum tanks from corrosion.