Page 364 - Intro Predictive Maintenance

A Total-Plant Predictive Maintenance Program 355

Unless the plant has a large population of electrical equipment or heat transfer systems,
the cost of implementing a full infrared scanning system is prohibitive. For plants that
have less of this type of equipment or systems, the most cost-effective method of
including the benefits of full infrared scanning is to purchase periodic surveys of plant
equipment from companies that specialize in these services.

A full survey of plant equipment should be conducted at least twice each year. The
frequency should be determined by the impact these systems have on plant produc-
tion. In addition to process and electrical systems, a full thermal scan of roofs and
other building envelope parameters should be conducted every five years.

Tribology
Unless the plant has a large population of machinery and systems that are highly
susceptible to damage as the direct result of lubricating oil contamination or has
an extremely high turnover on lubricating inventories, the cost associated with using
tribology techniques as part of a continuous predictive maintenance program is pro-
hibitive. In fact, even in the exception cases noted, the cost and training required to
use these techniques may not be cost effective.

Numerous companies provide full lubricating oil analysis on either a regular sched-
ule or an as-needed basis. Most plants can achieve the benefits of tribology without
the capital or recurring costs required to perform the function in-house. As a routine
predictive maintenance tool, tribology should be limited to the simpler forms of
tribology analysis (i.e., lubricating oil analysis and spectroscopy). The data provided
by these two techniques will provide all of the information required to maintain the
operating condition of the plant.

Wear particle analysis should be limited to a failure-mode analysis tool. If there is a
known, chronic problem in plant machinery, this technique can provide information
that will assist the diagnostics process. Otherwise, it is an unnecessary expense.

16.1.2 The Optimum Predictive Maintenance System
Predicated on the predictive maintenance requirements of most manufacturing
and process plants, the best predictive maintenance system would use vibration
analysis as the primary monitoring technique. The system should provide the ability
to automate data acquisition, data management, trending, report generation, and diag-
nostics of incipient problems, but the system should not be limited to this technique
alone. The optimum system should include visual inspection, process parameter mon-
itoring, limited thermographic monitoring, and the ability to calculate unknown
values.

In addition, the optimum system will permit direct data acquisition from any com-
mercially available transducer. This will permit direct monitoring of any variable that
may affect plant performance. One example of this feature would be the ability to