Question 254Steam Plants - Assistant Engineer

The correct answer is A) secure the feed water supply to the boiler. When a boiler tube ruptures and the water level cannot be maintained in the gage glass, the immediate priority is to prevent the water level from dropping further, which could lead to a dangerous dry-firing condition. Securing the feed water supply to the boiler stops the inflow of water, preventing the level from continuing to drop. This is the most critical first step to take in this emergency situation. The other options are incorrect because they do not directly address the immediate need to stop the water level from dropping. Closing the main steam stop, securing the forced draft fans, or stopping the fuel oil service pump do not directly address the water level issue and could potentially make the situation worse by allowing the boiler to dry out.