🔍 Key Concepts

• Impulse turbine rotor alignment and how main bearings support the rotor • How radial movement or sagging of the rotor would physically show up first in surrounding components • The difference between axial wear, radial wear, and temperature effects in a steam turbine

💭 Think About

• If a main bearing starts to wear, what happens to the rotor position relative to stationary parts (like diaphragms, seals, or casings)? • Which component listed in the choices is closest to the rotor and most sensitive to a small change in rotor radial position? • Would temperature at the exhaust end be the first thing to change, or would a mechanical clearance issue show up sooner?

✅ Before You Answer

• Identify which listed components are directly affected by small changes in rotor radial clearance. • Distinguish between mechanical contact/wear effects versus secondary effects like temperature changes or loosening fasteners. • Consider which component is located nearest the main bearings and rotating shaft in a typical impulse turbine layout.