Vibration Specifications Standards For Pumps and Vibration Alarm Limits
Pumps shall be defined in two (2) categories:
• Positive Displacement --including, but not limited
to Piston, Gear, and Vane.
• Centrifugal
Operating Conditions
• Non-cavitating non-separating condition.
• No piping strain.
• Shaft coupling aligned.
• Straight suction pipe to pump. (Reference Hydraulic
Institute Standard)
• Certification shall be performed while pumps are
operating within design specifications.
VIBRATION LIMITS FOR POSITIVE
DISPLACEMENT & CENTRIFUGAL PUMPS
For purposes of Line Amplitude evaluations a "PUMPING
FREQUENCY" (PF) band will be established. The PF Band
will be centered on the Pumping Frequency (Number of pumping
elements X Pump RPM). The band will extend + 2 lines of
resolution on either side of the line of resolution containing
the Pumping Frequency. (i.e. Bandwidth = 5 lines of resolution)
Excluding the lines of resolution contained in the Pumping
Frequency (PF) Band, the Velocity Amplitude (Inch/sec-Peak)
of any line of resolution, measured at bearing locations
in any direction (as defined in Section 4) shall not exceed
the Line-Amplitude Band Limit values specified and graphed,
when determined in accordance using the frequency range
from 0.3 X Running Speed (pump RPM) to Fmax = 120,000 CPM
(2,000 Hertz)
The Velocity Band-Limited Overall Amplitude (Inch/sec -
Peak) at bearing locations in any direction shall not exceed
the Pumping Frequency Band Limited Overall Amplitude Acceptance
Limit value specified in Table 9.4. and graphed when determined
in accordance using the frequency range from 0.8 X PF to
1.2 X PF.
The Acceleration Band-Limited Overall Amplitude (g's Peak)
at bearing locations in any direction shall not exceed the
Band-Limited Overall Amplitude Acceptance Limit values specified
and graphed when determined in accordance using the frequency
range from 0.3 X Running Speed to 300,000 CPM.
Figure 1 Line Amplitude Acceptance Limits
for Positive Displacement & Centrifugal Pumps
Figure 2 Band-Limited Overall Amplitude
Acceptance Limits for Positive Displacement & Centrifugal
Pumps
VIBRATION FOR VERTICAL MOUNTED
PUMPS
Vertically mounted pump systems with a "Vertical Mount
Height" greater than 5 feet will have an allowable
increase in Velocity Amplitude Acceptance Limits in Bands
1, 2, and 3 of 5% per foot of "Vertical Mount Height"
greater than 5 feet. (e.g. A 7 foot Vertical Mount Height
would yield a 10% increase [(7 ft - 5 ft) x 5%/ft]
Velocity Amplitude Acceptance Limits specified for Bands
1, 2, and 3. Therefore the limit for Band 1 would be [0.4
Inch/sec + (0.4 Inch/sec x 0.1)] = 0.44 Inch/sec-Peak.
Vertical Mount Height is defined as the furthest measurable
distance from the machine mounting to the end of the driver
or the end of the pump, which ever is greater.
