5.1 Introduction

Present day requirements for enhanced reliability of rotating equipment are more critical than ever before, and the demands continue to grow constantly. Advances are constantly made in this area, largely due to the consistent demand from the hydrocarbon, power-generation, process and transportation industries.

Due to the progress made in engineering and materials science, rotating machinery is becoming faster and lightweight. They are also required to run for longer periods of time. All of these factors mean that the detection, location and analysis of faults play a vital role in the quest for highly reliable operations.

Using vibration analysis, the condition of a machine can be constantly monitored. Detailed analyses can be made to determine the health of a machine and identify any faults that may be arising or that already exist.

In this chapter, further attention is given to the method of correlating rotating machine defects to vibrations collected and displayed by the various types of analyzers.

5.2 Commonly Witnessed Machinery Faults Diagnosed by Vibration Analysis

Some of the machinery defects detected using vibration analysis are listed below:

• Unbalance

• Bent shaft

• Eccentricity

• Misalignment

• Looseness

• Belt drive problems

• Gear defects

• Bearing defects

• Electrical faults

• Oil whip/whirl

• Cavitation

• Shaft cracks

• Rotor rubs

• Resonance

• Hydraulic and aerodynamic forces.

We will now look at each one of the above cases in detail and see how they manifest in vibration analysis.