Question 253Steam Plants - Assistant Engineer

The correct answer is A) the auxiliary stop valve fully open and the auxiliary stop-check valve used to regulate the amount of flow. Under emergency operating conditions, the auxiliary stop valve should be fully open to allow the maximum amount of feed water flow to the boiler. The auxiliary stop-check valve should then be used to regulate the amount of flow as needed, rather than restricting the flow through the auxiliary stop valve. This ensures the boiler receives the necessary feed water to maintain safe operating conditions during an emergency. The other options are incorrect because they either have the wrong valves fully open (B and C) or rely on the feed pump speed or a feed water regulator (C and D) to control the feed water flow, which is not the proper procedure under emergency conditions.