Page 78 - Machinery Component Maintenance

Maintenance Organization and Control for Multi-Plant Corporations 63

nected. On some machines with internal oil tubing, it is possible to have
oil flow showing in the main oil drain sight flow indicator while no oil is
reaching the bearings or seals!

Documenting What You’ve Done

Following the overhaul, the startup will need to be monitored. If you
don’t have a fixed-base monitoring system, use a portable real time ana-
lyzer and a multichannel FM tape recorder to obtain baseline vibration
data for comparison with previous operating information. Hot alignment
readings can usually be taken several hours after startup. Machine per-
formance will normally be checked after the process has stabilized
which, on some machines, can be as long as several days after startup.
All of this information provides a very useful check on the success of the
overhaul and should be taken at the outset of a run and not delayed until a
“convenient” time several weeks from startup.
As soon as the machine is operating satisfactorily, do the paper work.
Many engineers shy away from this duty and use the excuse of day-to-
day business pressures to delay or even forget this very necessary chore.
While the events are still fresh in your mind, sit down and finish the job.
In documenting an equipment overhaul, consider using the following for-
mat:

I. Basic Machine Data-A brief description of the machine, includ-
ing manufacturer, model number, number of stages and other
physical parameters. serial number. date purchased. date of last
overhaul and reason for current overhaul.
2. Performance, Vibration, and Mechanical Health Data-A com-
parison of pre- and post-overhaul levels. Performance and vibra-
tion data for the train, including process flow, pressurc and tem-
perature, machine case, and eddy current probe vibration levels.
as well as oil supply pressure, temperature, and oil return temper-
ature. The performance data should be sufficient to accurately as-
sess the machine’s condition. Calibrated instruments are required.
3. Spare Parts-A complete list of spare parts for the machine, as
well as a list of parts actually consumed. Include machine manu-
facturer’s part number, as well as company warehouse stock num-
ber.
4. Critical Dimension Diagram-Complete with factory specifica-
tions, as-found dimensions (logged during disassembly), and as-
overhauled dimensions. This information must include items such
as total rotor float, thrust clearance. rotor position within the total