🔍 Key Concepts

• Bar-lift nozzle control valves and how multiple valves are opened in a timed/stepped sequence • The mechanical relationship between the valve bar, valve stems, and any adjusting or control elements • The difference between devices that TRIGGER motion (pilot devices/servos) and devices that SET the order/sequence of motion

💭 Think About

• Ask yourself: in a bar-lift system, once the valve bar is moving, what PHYSICAL feature actually decides which valve starts to open first, second, third, etc.? • Which choice describes a fixed, mechanical setting that can be adjusted during overhaul and then passively governs the sequence, rather than an active control device? • Look at each option and decide: is this something that could directly determine the order in which individual valves crack open, or is it more related to starting, speed control, or actuation in general?

✅ Before You Answer

• Identify which option describes a mechanical adjustment that could set relative opening points between valves on the same bar. • Eliminate options that mainly relate to turbine speed control or general actuation, not the exact order that individual nozzle valves open. • Confirm that your chosen factor would still determine the opening sequence even if the control oil pressure or speed governor settings were changed.