Amplification Factor for Centrifugal Compressor

[nirlt]

What is the significance of Amplification Factor (AF) for Centrifugal Compressor (API 617)?
In one of the project specification, we came across the requirement of AF less than 14. How does AF affect the machine behaviour / design?

 

[electricpete]

What is the significance? High amplification factor means poor damping and machine will vibrate excessively passing through critical.

How does it affect design? Design to meet specs.

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(2B)+(2B)' ?

 

[electricpete]

example - sleeve bearings have higher damping than rolling bearings.

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(2B)+(2B)' ?