6.5.2 LP cylinder supports
The LP cylinder casings are supported on feet in a similar manner to the HP and IP casings, but because of their relationship with the condenser they are limited in axial movement.
Consequently they are either joined together and fixed axially to the foundation at the centre or each fixed individually at one end. This causes larger differential axial expansion between rotor and casing than in the other cylinders, so the axial clearances are greater.
Diaphragms and carrier rings are located axially within cylinders by circumferential grooves in the casings. They are maintained concentric with the casing by radial keys at the horizontal and vertical centrelines.
The casings are all aligned by reference to the horizontal and vertical centrelines of the rotor at each bearing. The alignment of the rotor itself is discussed in Section 7.5 of this chapter.