Page 389 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

368 Major Process Equipment MaiMenunce and Repir

4. If naocondensing, close the exhaust valve and open turbine casing
dIainS.
5. If condensing, shut down the condensing equipment, open the tur-
bine casing drains and close the sealing steam shutoff valve.

Note: Do not apply sealing steam to the packing cases while the
turbine rotor is idle.

6. Allow the rotor to come to a complete stop and cool down before
turning off the cooling water or stopping auxili81y oil pump, iffur-
nished.
7. If the turbine is to be taken out of service for an extended period;
follow the storage instructions given in Chapter 12.

Operation of Emergency and Standby lbrblnes

It is important that turbines used for emergency and standby services
have drain lines open and isolating valves closed when the turbine is idle.
Wbines not used for extended periods should be inspectea and operated
occasionally to make certain that they are in good working condition.
Where impractical to operate the turbine, the rotor should be turned over
by hand to introduce oil to the journal bearings (oil ring lubricated tur-
bines). If an auxiliary oil pump is furnished (pressure lubricated tur-
bines), oil can be supplied to the bearings by operating the pump. The
introduction of dry nitrogen into the casing during shutdown periods is
also advisable to prevent corrosion.
Emergency and standby turbines do not require a wmup period be-
fote applying the load. They may be placed in service as rapidly as de
sired. Steam should not be admitted to the turbine casing by partially
opening the inlet steam shutoff valve while the rotor is stationary. This
condition will cause uneven heating of the turbine rotor and casing which
may result in a distorted casing, bowed rotor shaft or other related prob-
lems.
Only now are we ready to proceed to the topic of Steum Whine Main-
tenance.

Maintenance Overvlew
Industrial steam turbines, like most quality machinery, require peri-
odic maintenance and service. This section suppies turbine disassembly,
assembly and adjustment procedures. These procedures should be a fa-
miliar subject to maintenance personnel to assure effective repair work
and proper adjustments to components requiring service. Maintenance