Page 360 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Steam Turbines and Turboexpanders 339

Overhaul Procedures

Each plant has established specific overhaul procedures. Typically
they would feature points like:
1. Safety requirements
2. Worklist
3. Bar chart
4. Material list and equipment catalog
5. Tool list
6. Special service and equipment list
7. Procedures:
alignment
flexible diaphragm coupling
bearing assembly
casing
rotor assembly
internals
interstage seals
design clearances
8. Field notes
9. Clearance inspection forms
10. Critical path method chart
1 1. Photographs
Based on the steam turbine manufacturer’s specific operating and
maintenance instructions these documents are an invaluable part of the
technical inventory of petrochemical plant maintenance departments .4

Special Purpose Steam Turbine Operation and Malntenance

As petrochemical process machinery increases in complexity, proper
coordination of the operating and maintenance functions becomes an im-
portant aspect of machinery management. Someone once observed in an
exaggerated way that if one could see the “gray line” between machinery
operation and maintenance functions one would be in trouble. Large
steam turbines are no exception. A good example would be the running
in and startup of a special purpose turbine after an extensive overhaul. A
good machinery maintenance person will not wallc away after the over-
haul-his job seems never done. For instance careful carbon ring break-
in is often ignored or bypassed based on the justification of getting the
turbine on line a few hours sooner.