Question 49General Subjects - 1st Asst/Chief

The correct answer is C) completely drain the unit. When securing a jacket-water heated submerged tube evaporator for an extended period, it is crucial to completely drain the unit to prevent corrosion and damage. Leaving water or other fluids in the evaporator can lead to scale buildup, freezing, and potential equipment failure. Draining the unit completely is the recommended procedure to ensure the system is properly secured and protected during the extended downtime. The other options are incorrect because: A) adding descaling compound is not necessary for securing the unit, B) sealing the unit to exclude air does not address the need to remove any remaining fluids, and D) filling the unit with saltwater could accelerate corrosion and is not an appropriate solution for long-term storage.