Question 1 of 27070
Q
A sequential lift, nozzle valve control bar on a turbo-generator, utilizes which of the following operating principles?
A
A hydraulic piston raises or lowers individual valves according to pressure received from a governor.
B
A hydraulic piston raises or lowers groups of valves according to pressure received from a governor.
C
A servomotor, mechanically connected to nozzle valve handwheels, opens or closes the valves in accordance with the type of electrical signal received.
D
A lifting beam mechanism engages nozzle valve stems of varying lengths.
Question 1 / 270705eccefa1bacbc34ba4d47202
Question 1 of 270705eccefa1bacbc34ba4d47202

A sequential lift, nozzle valve control bar on a turbo-generator, utilizes which of the following operating principles?

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Question 1 of 27070
Q

A sequential lift, nozzle valve control bar on a turbo-generator, utilizes which of the following operating principles?

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🔍 Key Concepts

• Sequential lift vs. group (or partial-arc) admission in steam turbine nozzle valves • How a hydraulic piston typically acts on one valve versus several valves together • The meaning of a lifting beam mechanism and valve stem length differences

💭 Think About

• Think about what the term sequential lift suggests about how the nozzle valves open in relation to each other—do they open one by one, in groups, or all at once? • Which option describes an arrangement where some valves are engaged and lifted at different stages or in a specific order, rather than by identical, simultaneous motion? • How would varying the length of valve stems or using a beam affect which valves open first or later?

✅ Before You Answer

• Identify which choice clearly indicates step‑by‑step (in sequence) opening of the valves, not just "groups" or a single simultaneous motion. • Check whether the principle described depends on mechanical geometry (like stems/beam) versus pure hydraulic or electrical control alone. • Make sure the option you pick matches how a turbo‑generator nozzle valve control bar would physically achieve sequential operation.