Pump body vibration
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The feed pump of the heat transfer oil furnace was tested, using water as the testing medium. After the centrifugal pump was started normally, it experienced severe vibration and emitted a loud, sharp noise, after which the pump was shut down. All inlet valves were opened, and the pump was started despite the risk of burning out the motor; the outlet safety valve activated. After resetting it, the pump was restarted, and its operation was stabilized by adjusting the furnace outlet valve. How should such centrifugal pumps, which experience overcurrent when the outlet valve is opened wide and vibration due to pressure buildup when the outlet valve is closed, be dealt with?
Turning it on at the risk of burning out the motor... you can’t do that
Add a minimum flow line that should be opened first when the pump starts
The key is to determine whether the flow rate and pressure in areas where vibration is within acceptable limits can meet your process requirements. According to API 610, it is normal for the vibration level to exceed the allowable values in the abnormal operating range (outside 60%~120% of the optimal efficiency point). If the vibration is within acceptable limits and both pressure and flow meet the process requirements, the solution is simple: before starting the pump, slightly open the valve at the pump’s outlet and then start the pump. If that’s not possible, then it’s necessary to check the factory testing records as well as the installation quality control records. PS: I suspect that the flow-pressure curve of your pump is not gentle enough, and it’s possible that the power rating of your motor does not meet the requirements (for specific specifications, refer to API 610).
Oh, thank you! Go back and give it a try to see how it works!
It is recommended that you check the performance curve of the pump to see if there is a low-flow line; if not, remember to exhaust air before starting the pump and ensure it is properly filled.
If there is no low-flow line, the outlet valve can be slightly opened and then adjusted according to the situation
What does the minimum flow line mean? On a performance curve, shouldn’t the flow value correspond to a single point?
Unilaterally, if the selection exceeds the actual operating conditions, it is possible to choose to enable backflow and machine the impeller. Consult the manufacturer regarding operating conditions