Page 296 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

276 Major Process Equipment Maintenance and Repair

started. When this method of protection is used, a dry nitrogen
purge is recommended.
3. For adverse conditions or very long term storage, seal all openings
and fill the unit completely to the top with the lubricating oil. When
the equipment is to be operated, the seals must be removed, and the
oil level dropped to the proper operating level.
4. The most permanent method for long term storage of equipment is
to disassemble the gear unit and coat each part with a preservative
such as Cosmoline@ or an equivalent. Before the unit can be placed
in service, special cleaning with solvents will be necessary to re-
move all preservatives from the intemals and the lube components.

When a unit is inoperative, most gear manufacturers recommend that it
be inspected every thirty days to six months depending on the method of
protection. Any areas of the preservative not performing properly should
be removed with solvent and recoated.

Maintenance

Gear unit maintenance, whether preventive or after-the-fact, is one of
the most important aspects affecting satisfactory unit performance. Pre-
ventive maintenance can help to keep problems from Occurring. If they
do occur, timely maintenance can prevent problems from getting worse
and can even correct them in some cases if performed properly.

Preventlve Yalntenance

Good preventive maintenance habits will prolong the life of the gear
unit and possibly help in detecting trouble spots before they cause serious
damage and long downtime. Waning: When working near rotating ele-
ments, be certain the prime mover is turned off and locked. The follow-
ing schedule is recommended for most operating conditions:

1. Daily Maintenance
a. Check the oil level.
b. Check the oil temperature and pressure against previously estab-
lished norms.
c. Check for unusual vibration and noise.
d. Check for oil leaks.
2. Weekly Maintenance
Inspect oil filter for possible flow obstructions.