Page 423 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Steam Turbines and Turboexpana-ers 401

5. Clean the joint between the valve cover (21,35) and the steam chest
body (1). Apply a combination of paste and plastic string sealing
compounds on the sealing surfaces.
6. Replace the cover and tighten bolts (26).
7. Connect the governor valve linkage and adjust the valve travel.
Overload Hand Nozzle Valve

Note: Close all isolating valves and open drains to depressurize
turbine casing and steam chest before performing mainte-
nance on the hand valve.

Disassembly (Refer to Figure 8-6)

The hand valve assembly is bolted to the bottom half steam and turbine
casing. Remove cap screws (8) to remove hand valve from casing.

Adjustments

1. Keep the valve stem packing (4) tight by adjusting the packing fol-
lower (2).
2. Replace the packing when follower adjustment no longer prevents
steam leakage along the valve stem.

Assembly

1. Apply a thin coat of paste type sealing compound on the valve body
flange .
2. Coat the cap screw threads (8) with an anti-galling compound.
3. Bolt the valve body to the turbine casing and tighten.

Steam Turbine Lubrlcatlon
Proper lubrication is a primary factor in achieving maximum trouble-
free operation. Only the best grades of oil should be used for turbine lu-
brication. Using the best oils will help eliminate costly downtime due to
bearing failures and other lubrication related problems.

Basic Oil Requirements
Turbine manufacturers sometimes do not recommend specific brands
of oil; they ask equipment owners to consult reliable oil suppliers regard-
ing their lubrication requirements. The oil should be a premium quality
mineral lubricant which will readily separate from water and have mini-