Page 412 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

390 Major Process Eipipmen.t Maintenance and Repair

nozzles and overlaps the end nozzles by a minimum of five
blades. The reversing blade trailing edges must point in the
same direction as the nozzles.

7. Return the rotor assembly to the turbine casing.

Shaft Sleeve Seals

Three seals (47, Figure 8-5) mounted on the rotor shaft, prevent oil leak-
age from the steam end bearing housing (21 and 53) and exhaust end bearing
pedestal (12 and 54). The seals also restrict the entry of steam, dust and dirt
into bearing housings.

Disassembly

1. Remove the rotor assembly from the turbine casing as described in
the Removal Section.
2. Remove the drive coupling from the rotor shaft.
3. Remove the trip body (52, Figure 8-5) and rotor locating bearing (50)
from the rotor shaft.
4. Remove the two set screws (48) from each sleeve seal (47) and slide
the sleeve off the rotor shaft (43).

Replacement And AdJustment

1. Place sleeve seals (47, Figure 8-5) on the mor shaft (43).
2. Replace the rotor locating bearing (50) and trip body as outlined in
the Assembly Won.
3. Install the drive coupling on the rotor shaft.
4. Return the rotor assembly to the turbine casing.
5. Position the shaft sleeve seals to provide the axial clearances shown in
Figure 8-10.
6. Tighten set screws (48) to lock the sleeves (47) in position on the
shaft.
Note: The tops of the set screws must be below the outside diame-
ter of the sleeve seals.

7. Lock the set screws in place by staking the sleeve seals.
8. Replace the casing cover (3) and bearing caps.