Question 388Steam Plants - Assistant Engineer

The correct answer is A) before the boiler has been blown down or chemicals added. The reasoning for this is that a boiler water sample should be taken before the boiler has been blown down or chemicals added in order to get an accurate representation of the boiler's water condition. Blowing down the boiler or adding chemicals would alter the water composition, so taking a sample beforehand provides the most reliable data for evaluating the boiler's water quality. The other options are incorrect because B) sampling from the highest point in the feed system would not necessarily represent the boiler water, C) taking a sample after refilling with makeup water would not show the true condition of the boiler water, and D) taking a sample after blowing down the boiler would not provide the baseline information needed to properly assess the water condition.