Compressor Vibration

Reciprocating Machinery Vibration Short Course – Lecture Notes

Paper No. 69

K. E. Atkins, PCRC 9th Annual Gas Machinery Conference, Denver, CO, September 26-29, 1994 .

In recent years, vibration instrumentation, transducers, data collectors, etc. have experienced significant technological advances. Very powerful vibration analysis tools are now compact and relatively inexpensive. Sophisticated vibration trending software has also become readily available to assist the machinery user in analyzing vibration data and improving machinery reliability. Most of the hardware and software advances have been successfully applied to turbo machines, i.e., centrifugal compressors, pumps, electric motors, turbines, etc. Reciprocating machinery vibration is a special case of machinery vibration. Reciprocating machines generate far more complex vibration signatures than centrifugal machines and are therefore more difficult to analyze and diagnose problems. The purpose of this course is to provide some basic understanding of reciprocating machinery vibration measurements and various trouble-shooting techniques that can be used to identify and solve vibration problems.

A significant percentage of reciprocating machinery vibration problems are related to pulsation induced forces. Understanding pulsation is important for understanding reciprocating machinery vibration; however, it is not covered in this course. Other PCRC publications are available which cover pulsation analysis in detail.