Page 399 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Steam ltrrbines and Turboexpanders 377

Assembly
1. Clean all mating sealing surfaces between the bottom half turbine
casing, casing cover and packing cases.
2. Apply sealing compounds to the sealing surfaces as shown in Fig-
ure 8-8.

Note: Do not place plastic string sealant near turbine casing bolt
holes. A poor seal may result if string sealant enters these
holes.

3. Lower the casing cover onto the bottom half casing.
4. Seat the dowel pins (5).
5. Tighten bolts (4) at horizontal casing flange, starting with the bolts
located closest to the packing cases.
6. On small turbines, replace packing cases (10) as described in Pack-
ing Case Assembly. On larger turbines, tighten cap screws (7) on
vertical packing case flange.

Bearing Llnen,

Locating lugs on each bearing liner (15 and 16, Figure 8-5) engage
grooves in the horizontal split of the steam end bearing housing (21 and 53)
and exhaust end bearing pedestal (12 and 54). This arrangement retains the
liners in the proper position.

Dlrassem bly
1. Remove cooling water piping from bearing caps, if applicable.
2. Rcmove the dowels (14) and bolts (13, Figure 8-5) from the bearing
cap joints.
3. Break the joints by prying the bearing caps away from the bearing
housings.
4. Raise the caps approximately 1 in. (25 mm) and pry the top liners
(1 6) (at the locating lugs) from the bearing caps with a screwdriver.
This will release the oil rings (49) from the caps.

Caution: Attempting to remove the bearing caps, without prying
out the top bearing liners, can distort the oil rings. Dis-
torted oil rings will not rotate to provide lubrication,
thereby resulting in bearing failures.
5. Remove bearing caps and top journal bearing liners.