The balance drum of the multi-stage centrifugal pump is stuck
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This is a picture of the balance drum of a multi-stage centrifugal pump after it was removed. Since the shaft could not be rotated, it was found that the balance drum and the balance sleeve were stuck together. As for the several evenly distributed marks on the balance drum, their origin is unclear; moreover, no foreign objects were detected on the balance disk. I would be extremely grateful if any expert could help answer my questions.
Rotor runout. Perform dynamic balance checks, check the straightness of the pump shaft, and also inspect the bearings. The clearance between the balance drum and the balance sleeve is already very small.
Where is the picture? There is a situation in which changes in the medium conditions can also lead to the phenomenon you mentioned
Changes in the medium conditions, excessive bearing clearance, and shaft eccentricity cause friction between the balance drum and the balance sleeve, leading to high temperatures, wear, and jamming, making removal very difficult. The small protrusions have a hardness of 65 on the Rockwell scale; only by grinding away these high-hardness areas can they be removed so that assembly is possible.
Look carefully for the volume fluctuations. By the way, check whether there is any friction in the impeller vanes
Check the operating conditions and verify the axial positioning.
The flatness of the balance disk must not deviate by more than 0.02 mm