Page 109 - An Introduction To Predictive Maintenance

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PREDICTIVE MAINTENANCE

TECHNIQUES

A variety of technologies can, and should be, used as part of a comprehensive pre-
dictive maintenance program. Because mechanical systems or machines account for
most plant equipment, vibration monitoring is generally the key component of most
predictive maintenance programs; however, vibration monitoring cannot provide all
of the information required for a successful predictive maintenance program. This
technique is limited to monitoring the mechanical condition and not other critical para-
meters required to maintain reliability and efficiency of machinery. It is a very limited
tool for monitoring critical process and machinery efficiencies and other parameters
that can severely limit productivity and product quality.

Therefore, a comprehensive predictive maintenance program must include other mon-
itoring and diagnostic techniques. These techniques include vibration monitoring,
thermography, tribology, process parameters, visual inspection, ultrasonics, and other
nondestructive testing techniques. This chapter provides a brief description of each of
the techniques that should be included in a full-capabilities predictive maintenance
program for typical plants. Subsequent chapters provide a more detailed description
of these techniques and how they should be used as part of an effective maintenance
management tool.

6.1 VIBRATION MONITORING
Because most plants consist of electromechanical systems, vibration monitoring is the
primary predictive maintenance tool. Over the past 10 years, most of these programs
have adopted the use of microprocessor-based, single-channel data collectors and
®
Windows -based software to acquire, manage, trend, and evaluate the vibration energy
created by these electromechanical systems. Although this approach is a valuable pre-
dictive maintenance methodology, these systems’ limitations may restrict potential
benefits.

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