Page 391 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

370 Major Process Equ@mmt Maintenance and Repair

Table 8-8
Scheduled Maintenance Guidelines

Malnwnance Description
Daily 1. Check all oil levels and add oil as necessary.
2. Check bearing and lubricating oil tempemtura.
3. Check turbine speed.
4. Check smoothness of operation, investigate sudden
changes in operating conditions or unusual noises.
5. If daily shutdowns are made; test the trip valve by
striking the hand trip lever.
1. Exercise trip valve to prevent sticking due to depos-
its or corrosion. If on a continuous operating sched-
ule; exercise the trip valve by striking the hand trip
lever. Reset the lever when the turbine speed de-
creases to approximately 80% of rated speed.

1. sample lubricating oil and renew as necessary.
2. Check governor Linkage for excessive play. Replace
any worn parts.
3. Check the overspeed trip by overspeedtng them-
bine (if the driven machine permits).

1. Check all clearances and adjustments.
2. Remove and clean steam strainer. If strainer is ex-
ceptionally dirty, clean every six months.
3. Inspect governor valve and valve seat. Hand lap the
valve if signs of unevem wear exists. Replace the
governor valve stem packing if necessary.
4. Clean and inspect trip valve. Replace worn parts
and hand lap if necessary.
5. Disassemble, clean and inspect overspeed trip and
linkage. Inspect trip pin and check for ease of aper-
ation. correct clearance to plunger.
6. Check journal bearings and rotor locating bearing
for wear and replace if necessary. Adjust bearing
case alignment for good liner bearing contact.
7. Inspect and clean bearing housing oil reservoirs and
cooling chambers.
8. Lift turbine casing cover end inspect rotor shaft,
disks, blades and shrouding.
9. Inspect carbon rings and replace as necessary.
10. Remove rotor assembly Erom casing and inspect re-
versing blades and nozzle ring.
11. Check operation of sentinel valve.
12. Adjust and check overspeed trip when turbine is put
back in operation.