Page 406 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

384 Major Process Equipment Maintenance and Repair

6. Remove the cap screws and spacers. Mark each spacer so it can be
returned to the location from which it was removed.

Caution: If spacers (24, Figure 8-5) are not returned to their original
locations, bearing misalignment may occur. This will cause
uneven bearing wear or possible failure.

7. Slide the pedestal off the combining studs and dowel pins (25).

Replacement
Note: Bearing anti-rotation locating grooves must be provided at
the horizontal split on replacement bearing pedestals. These
grooves may be made by hand filing. Hold the liner so the
tab is on the upstream end for clockwise rotation (looking in
direction of steam flow) and on the downstream end for
counterclockwise rotation.

1. Slide the pedestal onto the combining studs (17, Figure 8-5) and dowel
pins (25).
2. Replace the spacers (24) and cap screws (23). Spacers must be re-
turned to the same locations from which they were removed.
3. Tighten the cap screws (23) and insert the taper pins (1 8) in the ped-
estal and combining studs (17).
4. Replace the rotor assembly as outlined in Replacement Section.
5. Replace the bottom half journal bearing liners (15). Check the bear-
ing alignment and adjust as necessary.

Steam End Bearing Housing Replacement

The steam end bearing housing (21 and 53, Figure 8-5) is attached to
the turbine casing by four socket head cap screws (23). Two dowel pins
(B), pressed into the steam end of the turbine casing, maintain the bear-
ing housing in correct horizontal and vertical parallel alignment with the
exhaust end bearing pedestal (12 and 54). Spacers (24) , located between
the housing and turbine casing, are used to correct any angular misalign-
ment and also to adjust the axial position of the turbine rotor in the cas-
ing.

Disassembly
1. Remove the rotor assembly as outlined in Removal Section.
2. Remove the hold-down bolts and dowel pins from the steam end bear-
ing support (29, Figure 8-5).