Reasons for excessive vibration in single-stage centrifugal pumps
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Our facility has an IS80-50-315 centrifugal pump used to transport clean water, with a head of 125 meters. Over the past year, two new pumps have been installed; however, after operating normally for two months, these pumps developed significant vibration and required maintenance. The maintenance personnel checked and found no issues; the foot bolts had also been tightened again. Upon disassembling the pump body, it was determined that the bearings were not damaged, and there were no foreign objects inside the impeller. Previously, the technical staff believed that stress was present in the pipes, and after the construction team carried out repairs on them, the vibration problem still persisted. I would like to ask the teachers here: what are some other reasons that can cause excessive vibration in pumps? How can we completely solve the problem of vibration in this water pump? PS: The water pump was working well before replacing it with a new motor; however, after installing the **latest energy-saving motor, the frequency of vibrations increased significantly. Could this be a problem with the motor?
It’s not a problem with the motor; it’s a compatibility issue. You can’t just replace the motor; the pump also needs to be replaced. Replacing the motor further reduced the pump’s efficiency. Your question is very easy to explain
Has the design verified the matching between flow rate and motor load?
Is the pump’s flow rate operating within the allowable range, and have the device’s feet been checked?
For the IS clean water pump, is it horizontal or vertical? Check whether the connection between the motor and the pump is proper. If it is vertical, it is likely that the axis alignment of the motor is not good; in the case of a horizontal setup, calibration is needed.
The pump was working normally at first, but problems arose after 2 months of operation. Is the alignment as per the specifications within acceptable limits? Also, whenever disassembly and maintenance are carried out due to excessive vibration, does the impeller locking device become loose? Is it possible that improper operation caused the pump to stop, and backflow led to loosening of the impeller due to reverse force?
It’s a horizontal model; the connection between the motor and the pump has been adjusted, but similar problems still occur.
Thank you for the reminder; I really hadn’t paid attention to this. I’ll check after disassembling it tomorrow to see if the impeller locking mechanism is loose.
Well, it mainly appears after running for a while, rather than from the start :)