Final answer:
False. The valve between a boiler and water column must be visibly open but not locked during operation.
Step-by-step explanation:
False. If there is a valve in line between a boiler and the water column, it must be visibly open but not locked in the open position during operation. The purpose of this valve is to prevent the boiler blowdown from reaching the water column in case of an emergency. If the valve were to be locked in the open position, it would defeat the purpose of having the valve.