The pump is vibrating heavily; everyone, come take a look!
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In a post that was just published, it was mentioned that the water jacket and bearing housing of one pump had cracked due to overheating. It’s a liquid hydrocarbon pump with a power rating of 75 KW, and it uses dry gas seals. A new set of dry gas seals, as well as a new water jacket and bearing housing, were installed. After that, the pump was put back into operation. But things didn’t go well – the vibration level reached 2.5 millimeters. The pump was aligned twice; both attempts failed. An expert was called in for a third alignment attempt, but that too didn’t work. It seems that the problem isn’t related to alignment. I’m puzzled as to why such a significant change in vibration occurred just after replacing those components. I don’t understand it. I hope experts can offer some advice. The outlet pressure of this pump is 3.8 MPa, the flow rate is 18 T/h, and the current consumption is 85 A. By the way, during operation, the current value fluctuates between 80 and 85 A. But the outlet pressure remains unchanged. Ugh, I’m confused. Does this pump really need to be overhauled?
Has severe cavitation occurred? Liquid hydrocarbon pumps are prone to cavitation.
Excessive pump noise/Vibration – Pump not operating within its range – NPSH requirements not met – Pump wear – Pump misalignment – Wear of elastic coupling components – Faulty anti-friction bearings – Impeller failure – Loose foundation bolts – Check the system – Check the system – Replace the pump – Align the pump properly – Update/replace coupling components – Replace bearings – Replace the impeller – Tighten foundation bolts again
I can only offer some simple suggestions: What is the interchangeability of the bearing housings? This is a major issue: are the bearing housing and the pump body completely interchangeable when assembling the pump? What changes have occurred in the process conditions? Has cavitation occurred?
It is recommended to check the pressure gauge. Logically, there are two main reasons for large current fluctuations: mechanical problems, or fluctuations in pump flow. Based on the observed symptoms, cavitation might be the cause, but inaccurate judgments can result from faults with the pressure gauge
In addition to what the people upstairs mentioned, if the pump shaft hasn’t been replaced, has it been checked to see if it’s deformed? If not, that could also be one of the possible causes. :lol