excessive. The vibration levels at the top of the motor were often above 20 mils peak to peak which exceeds the Hydraulic Insti tute acceptable vibration limit of six mils for vertical pumps at 900 cpm 1. Although the vibration levels were excessive, it was not known whether the motor vibrations were related to the wear problems on the pump.
Vibration monitoring instruments for pumps are generally characterised as velocimetric type. Velocimetric type instruments have a measuring range typically in inches/sec or mm/sec. Accelerometric or distance type vibration readings are usually taken at bearings and shafts of more high tech equipments like turbines.
Many facilities want to monitor pump vibration, but do not want an expensive vibration program. 4 20 mA sensors output overall vibration levels so that maintenance professionals can take action on pumps that indicate abnormal or increasing vibration. Slide 14 Vibration monitoring of pumps, 2008
The overall vibration velocity levels are over 0.8749 In/Sec Peak . Overall vibration was in excess of 0.6 In/Sec Peak which indicates an advanced fault. Refer to Figure 1.
This calculator can be used to determine the vibrational velocity for a given peak to peak displacement a given frequency . If you enter any two of these variables as inputs, the calculator will determine the third variable.
Pump Vibration Settings In Mils Subsynchronous Vibration In Vertical Pumps International Pump Users Symposium March, 2010 Evaluating and Correcting Subsynchronous Vibration In Vertical Pumps.
For pump type groupings provides overall vibration velocity acceptance criteria For solids handling pumps acceptable values dependent on: Pump power Vertical vs. horizontal orientation Operating region For operation below 600 rpm add allowable displacement Factory vs. field AOR vs. POR