Page 403 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Steam Turbines and Turboexpandem 381

8. When the locating lugs are properly seated, replace the dowels
(14).
9. Tighten all bolts (13).
10. Connect cooling water piping to bearing caps, if applicable.

Water-Cooled Bearings

Provisions for cooling the bearing oil are supplied as standard equip-
ment on oil ring lubricated turbines. The lubricating oil is cooled by wa-
ter flow through chambers in the bottom halves of the steam end bearing
housing and exhaust end bearing pedestal. Water-cooled bearing caps are
supplied when additional cooling is required on oil ring lubricated tur-
bines. Water-cooled bearing caps are furnished as standard equipment on
many larger turbines when oil ring lubricated.

Caution: If the turbine is idle during cold weather, the cooling wa-
ter chambers must be drained to prevent damage from
freezing water.

Disassembly

1. Disconnect cooling water piping from the cooling chamber flanges
(27 and 56, Figure 8-5) and bearing caps (53 and 54) as applicable.
2. Remove machine bolts (20) from the cooling chamber flanges.
3. Remove the flanges (27 and 56), gaskets (19) and cooling tube as-
semblies from the bearing housings.
4. Remove the bolts (59) from the bearing cap covers (58), if applica-
ble.

Adjuatmmts

1. During operation, adjust the water flow through the chambers to
approximately 2 gpm (7.5 l/min). Cooling water pressure should
not exceed 75 psig (5 bar).
2. Annually clean and inspect the cooling water chambers. (See nble
8-6).

Assembly
1. Install new gaskets (19 and 57, Figure 8-5).
2. Replace the flanges (27 and 56) on the cooling chambers.
3. Replace the cooling chamber flange bolts (20) and connect the cool-
ing water piping.