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There are two types of
standard pumps. The first is the Overhung pump which has the impeller at one
extreme end and the shaft is supported by two bearing on only one side of
the impeller as in the diagrams above. The other pump design is known as a
Counterhung pump in which the shaft extends beyond the impeller and is
supported by bearings on each side of the impeller. Despite their
differences, both of these pump designs are monitored in the same fashion.
Pump vibration frequencies
of interest include pump unbalance, input shaft
alignment, and bearing defect frequencies. A complete continuous monitoring
approach should include one accelerometer per bearing location. Mounting
orientation for the accelerometers should be horizontal at the bearing. Economical standard accelerometers such
as the CMCP1100 are well suited to
this application. The accelerometers should be used with
CMCP530A Vibration Velocity Monitors.
An additional accelerometer can be mounted to the impeller housing to detect
higher frequency conditions such as vase pass by use of a
CMCP525A Vibration Acceleration Monitor.
A complete vibration monitoring system
includes:
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One accelerometer mounted to each
bearing housing -
CMCP1100
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One accelerometer mounted to the
impeller housing -
CMCP1100
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Two Vibration Velocity Monitors -
CMCP530A
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One Vibration Acceleration Monitor -
CMCP525A
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Options include:
For additional reading STI offers several
application notes with a more in depth discussion at
STI Application Notes |
