Page 424 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

402 Major Process Equipment Maintenance and Repair

mum tendency to emulsify or foam when agitated. It should have high
rust and oxidation resistance and minimum sludge, lacquer, varnish or
resin forming tendencies. In addition to these requirements, Tables 8-5 and
8-8 contain other necessary information to aid in selecting the proper lubri-
cating oil for your turbine.
%bines driving through speed reduction or increasing gears are often
pressure lubricated by the gear lubrication system. Refer to the gear man-
ufacturer's instructions for gear oil requirements.

Care of Oil
Lubricating oil should be maintained in first class condition by pre-
venting contamination from moisture, dust, dirt or other impurities. An
oil maintenance analysis program is recommended for determining the
frequency of oil changes. Consult your oil supplier for assistance in es-
tablishing a program that will meet your specific lubrication maintenance
requirements. Refer also to Chapter 12.

Methods of Lubrication
Most steam turbines are furnished with either an oil ring lubrication
system or a pressure lubrication system. Pressure lubricated turbines

~
Table 8-9
Rotor Class Designations and Consbudion Features
for Single-Stage Turbines

CLASS 1 CLASS 2 CLASS 3
service Low PRESSURE, MEDIUM PRESSURE MEDIUM PRESSURE
MEDIUM MEDIUM HIGH
Component TEMPERATURE TEMPERATURE TEMPERATURE
Shaft Medium carbon Chromemolybdenum Chromemolybdenum
steel Steel steel
Disk Low alloy high Medium alloy high Medium alloy high
strength steel strength steel strength steel
TripDevice Standard Standard Special