Coast Guard Exams
Question 673Steam Plants - Assistant Engineer70% to pass

The labyrinth packing ring in an interstage diaphragm of an impulse turbine is prevented from rotating by _______________.

AI Explanation
The correct answer is B) a horizontal key joint extending into a slot. The labyrinth packing ring in an interstage diaphragm of an impulse turbine is prevented from rotating by a horizontal key joint that extends into a slot. This key joint locks the packing ring in place and prevents it from rotating, ensuring the proper sealing and functioning of the turbine. The other answer choices, such as spring tension, steam pressure, or the weight of the diaphragm, do not directly prevent the rotation of the packing ring in this specific component of the turbine.