Machinist's Mate (MM) Advancement Practice Test 2025 – Complete Prep Resource

The method that is NOT one of the five wet lay-up methods is chilled water. Wet lay-up methods are used for preserving boilers and other equipment when they are taken out of service to prevent corrosion and other types of damage. The methods typically involve using water or solutions that inhibit corrosion.

The steam blanket, for example, involves using steam to create a blanket effect to prevent the equipment from coming into contact with air, thus reducing the likelihood of corrosion. Hot deaerated fill involves filling the system with hot water that has had the oxygen removed, which helps in minimizing corrosion. Sodium nitrate is employed in some wet lay-up methods as a corrosion inhibitor.

Chilled water, on the other hand, is typically associated with cooling systems rather than preservation techniques. It does not serve the purpose of inhibiting corrosion in the way the other methods do, hence it is identified as the outlier in this context. This distinction is crucial for understanding how different preservation methods operate and their specific applications in marine engineering.