What would be the first indication that a tube leak has occurred in area "23"? Illustration MO-0111

Correct Answer: Option D — The level in area "1" would decrease.

In a flash evaporator, area 1 represents the feed water supply or heating section. A tube leak in the heat exchanger (area 23) causes a loss of fluid from the primary circuit into the secondary side, resulting in a measurable decrease in the level within the affected section.