Page 268 - Intro Predictive Maintenance

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VISUAL INSPECTION

Regular visual inspection of the machinery and systems in a plant is a necessary part
of any predictive maintenance program. In many cases, visual inspection will detect
potential problems that will be missed using the other predictive maintenance tech-
niques. Even with the predictive techniques discussed, many potentially serious prob-
lems can remain undetected. Routine visual inspection of all critical plant systems will
augment the other techniques and ensure that potential problems are detected before
serious damage can occur.

Most of the vibration-based predictive maintenance systems include the capability of
recording visual observations as part of the routine data acquisition process. Because
the incremental costs of these visual observations are small, this technique should be
incorporated into all predictive maintenance programs.

All equipment and systems in the plant should be visually inspected on a regular basis.
The additional information provided by visual inspection will augment the predictive
maintenance program regardless of the primary techniques used.

As was pointed out previously, inspection is a key to detecting the need for preven-
tive maintenance requirements. It should be nondestructive so that it will not harm the
equipment. Some common methods of nondestructive testing (NDT) are outlined as
follows:
1. Body Senses —Thermometer
—Sight —Crayons, stickers, paints
—Smell —Infrared
—Sound —Thermopile
—Taste —Heat flow
—Touch 3. Vibration Wear
2. Temperature —Accelerometer
—Thermistor —Stethoscope

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