Page 21 - Machinery Component Maintenance

Machinery Maintenance: An Overview 7

The terms overhaul and repair are often reserved for maintenance ac-
tions that improve the conditions of an item, but may or may not establish
“good as new” condition. In fact, overhaul is often interpreted as a pre-
ventive maintenance action while repair is strictly reserved for mainte-
nance of an item that has reached a defined failed state or defect limit?.
Replucemenr should be understood in our context as a broad term that
includes the replacement of components, operating fluids and charges, as
well as of complex machinery and systems. Finally, we understand or-
ganizational srrucrure problems in machinery maintenance as those con-
cerns that deal with maintainability parameters such as facilities, man-
power, training, and tools. Figure 14 illustrates this point.
Most petrochemical process plants have a preventive maintenance
(PM) system. The authors know of a plant where 95 96 of the maintenance
work orders are turned in by the PM crews and not the operators. While
this is an extreme-and probably not a very cost effective-way of fail-
ure fighting, we can support a moderate approach to machinery PM.
This moderate approach begins with an attempt to plan all PM actions by
following this pattern:

1. Determine what defect, failure, or deterioration mode’ it is you
want to prevent from occurring.
2. Determine whether the defect, failure, or deterioration mode can be
prevented by periodic actions. If not, determine how it can be pre-

WINTAINABILITY

MAXIMIZE OWOFF-LINE HAXIMIZE f44XIMIZE
MTC. ACCESSIBILITY MINIMIZE ON-LIHE CONDITION/ ECONOllICALLV
ON-LINE INSPEC PERFOMNEE INSURAHCE
CLEANING MONITORING AND SPARE PARTS
pn -
(SERYICIBILITY)
LIGHTING
SPECIAL TWLS
SHELTER
ACCESSIBILITY
OTHER

Figure 1-4. Process machinery maintainability components.