Question 62Steam Plants - 1st Asst/Chief

The correct answer is D) remove settled solids from the water drum. Bottom blow valves are installed on auxiliary water-tube boilers to remove any settled solids that accumulate in the bottom of the water drum. This helps maintain the proper water level and composition within the boiler, preventing sludge and scale buildup that could impair boiler efficiency and potentially lead to damage. The other answer choices are incorrect because: A) is too broad, as bottom blow valves are not intended to completely drain the boiler; B) refers to preventing sludge in the steam drum, not the water drum; and C) is focused on removing floating impurities, while bottom blow valves target settled solids.