Page 126 - An Introduction To Predictive Maintenance

116 An Introduction to Predictive Maintenance

7.1.3 Quality Control

Production-line vibration checks are an effective method of ensuring product quality
where machine tools are involved. Such checks can provide advanced warning that
the surface finish on parts is nearing the rejection level. On continuous-process lines
such as paper machines, steel-finishing lines, or rolling mills, vibration analysis can
prevent abnormal oscillation of components that result in loss of product quality.

7.1.4 Loose or Foreign Parts Detection
Vibration analysis is useful as a diagnostic tool for locating loose or foreign objects
in process lines or vessels. This technique has been used with great success by the
nuclear power industry, and it offers the same benefits to nonnuclear industries.

7.1.5 Noise Control
Federal, state, and local regulations require that serious attention be paid to noise
levels within the plant. Vibration analysis can be used to isolate the source of noise
generated by plant equipment as well as background noises such as those generated
by fluorescent lights and other less obvious sources. The ability to isolate the source
of abnormal noises permits cost-effective corrective action.

7.1.6 Leak Detections
Leaks in process vessels and devices such as valves are a serious problem in many
industries. A variation of vibration monitoring and analysis can be used to detect
leakage and isolate its source. Leak-detection systems use an accelerometer attached
to the exterior of a process pipe. This allows the vibration profile to be monitored in
order to detect the unique frequencies generated by flow or leakage.

7.1.7 Aircraft Engine Analyzers
Adaptations of vibration-analysis techniques have been used for a variety of specialty
instruments, in particular portable and continuous aircraft engine analyzers. Vibration-
monitoring and analysis techniques are the basis of these analyzers, which are used
to detect excessive vibration in turbo-prop and jet engines. These instruments incor-
porate logic modules that use existing vibration data to evaluate the engine condition.
Portable units have diagnostic capabilities that allow a mechanic to determine the
source of the problem while continuous sensors alert the pilot of any deviation from
optimum operating condition.

7.1.8 Machine Design and Engineering
Vibration data have become a critical part of the design and engineering of new
machines and process systems. Data derived from similar or existing machinery can
be extrapolated to form the basis of a preliminary design. Prototype testing of new