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Centrifugal Pumps Design and Application 2nd ed - Val S. Lobanoff, Robert R. Ross (Butterworth-Heinemann, 1992)

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460 <strong>Centrifugal</strong> <strong>Pumps</strong>: <strong>Design</strong> <strong>and</strong> <strong>Application</strong><br />

Figure 18-23. Comparison of residual unbalance criterion.<br />

bearing. These vibrations should be continuously monitor<strong>ed</strong> with provision<br />

made for automatic alarm <strong>and</strong> shutdown capabilities to protect the<br />

installation from damage.<br />

For oil film bearings, the following guidelines for defining maximum<br />

acceptable vibration levels are sometimes us<strong>ed</strong> when code allowables do<br />

not apply. If the vibrations are less than one-fourth of the diametrical<br />

bearing clearance, then the vibrations may be consider<strong>ed</strong> acceptable. Vibration<br />

amplitudes (A, peak-to-peak) greater than one-half the diametrical<br />

clearance (Ca) are unacceptable, <strong>and</strong> steps should be taken to r<strong>ed</strong>uce<br />

them.

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