The centrifugal pump vibrates heavily
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Horizontal centrifugal pump: steel-lined PTFE, Q=220 m3/h, H=32 m, N=55 Kw, rotation speed 2985 r/min. During testing, vertical vibration was measured at 9 microns; there were no issues with the shaft alignment. The cause is unknown – please help identify it
Vibration during testing – it’s a new pump; have all the areas that need to be checked been inspected? Things such as elastic blocks, the stability of the pump foundation, bearing installation clearance, and the tightening of various components – it is also advisable to loosen the coupling and test the motor separately.
It’s a new pump; the motor worked fine when tested individually. The bearing at the pump coupling end is overheating, with a vertical vibration value of 9 units.
Analyzing vibration problems is complex, as vibrations can be caused by both manufacturing factors and operational conditions in the field. First, you need to ensure that the unit is operating near the conditions specified on the nameplate and that it is properly aligned. Once these aspects are fine, then you can look for reasons related to the manufacturer.
If your alignment is good but there is still high radial vibration, possible reasons: 1. The bearing installation is not proper； 2. Improper adjustment of the dynamic and static clearances ； 3. It is also possible that the material of the components is of poor quality, resulting in thermal deformation and other issues. The system should be checked, for example regarding your bearing assembly: what is the dimension of the shaft journal? What is the inner diameter of the bearing inner ring? What is the inner diameter of the bearing housing? What is the outer diameter of the bearing’s outer ring? Is this to confirm that you measured and verified during installation that your alignment is good? So what are your data?
What is the stiffness of the pump base? Are the foundation bolts loose? If the bearing temperature is high, could it be due to misalignment? Measure the lower frequency spectrum to examine its components, so as to confirm further.
This is a unitary pump, not a split-type pump; any disassembly or inspection must be carried out by the manufacturer. The centering data is within the 5-range.
The assembly precision is insufficient, which is a quality issue on the part of the manufacturer.
Under normal circumstances, the horizontal vibration of a pump is greater than its vertical vibration. The fact that the vertical vibration is high now indicates that there is an issue with the stiffness of the pump’s support structure; check whether the bolts holding the support legs are loose