Question 84General Subjects - 1st Asst/Chief

You are correct, the answer A) reduce electrolytic action on heat exchanger metals is the correct answer. Sacrificial zinc anodes are used in saltwater systems, like heat exchangers, to protect against galvanic corrosion. The zinc anode is designed to corrode preferentially over the other metal components, thereby protecting the heat exchanger from deterioration due to electrolytic action between dissimilar metals in the saltwater environment. This prevents damage to the heat exchanger surfaces. The other answer choices are incorrect because they do not accurately describe the primary purpose of sacrificial zinc anodes in this application. Keeping the heat transfer surfaces shiny/clean, preventing marine growth, and providing a protective coating are not the main functions of these anodes.