Page 471 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

448 Major Process Equipment Maintenance and Repair

Because the multidiscipline approach is the most user-intensive, it is
worth exploring in greater detail. Here it would be well to look at one major
petrochemical company’s approach to gas turbine maintenan~e.~ Problems
were identified with the more traditional approaches to gas turbine mainte-
nance:
1. Adequate records are not kept on mechanical condition before re-
pairs; specific repairs made; and clearances, fits, and finishes when
new, before repairs, and after repairs.
2. Knowledge gained from failure analysis walks out the gate with the
consultant andor repair crew, and it never gets back to the people
who own the equipment.
3. The personnel actually responsible for day-to-day operation of ma-
chinery often do not learn the characteristics of their machines, the
things to watch for, and how to improve the machine performance.
4. Often, engineers or specialists sitting in remote offices make deci-
sions that affect a machine’s performance. However, these decision
makers have never experienced living with their decisions.

The objectives of the approach taken at this facility were:

1. To create in-house technology, so repairs can be made intelligently
and without delay.
2. To operate machines at the maximum efficiency allowable by con-
struction materials, instruments, and operating parameters.
3. Not to shut down a machine for overhaul without a scientific reason
for doing so.

To accomplish these objectives the responsibility for gas turbine main-
tenance was distributed among various plant functions and specialists.
These included alignment, lubrication, metallurgical engineering , weld-
ing, inspectionlNDT, and mechanical engineering. In essence , what has
been done is to achieve managerial control of the engineering factors that
influence the reliability of the machines. This has enormous advanpges
if managed correctly, but is only as strong as the individual specialists in
the team.3
Mr. Hall lists the results of this approach at his site as:

1. Gas turbine turnaround time has been reduced approximately 50
percent.
2. Manpower usage has been reduced approximately 50 percent.