When checking zinc plates or pencil zincs in the refrigerating system condenser, what should you do?

Correct Answer: Option A — replace the zincs if deteriorated by 50%

Sacrificial zinc anodes in seawater-cooled condensers protect expensive copper-nickel tube sheets from galvanic corrosion. Standard marine engineering practice dictates renewing these sacrificial elements when they have suffered fifty percent deterioration to maintain continuous galvanic protection.