Vibration problems of horizontal centrifugal pumps
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The light naphtha transfer pump uses a 11+52 sealing design; the outlet pipeline experiences significant vibration. Fixed supports were installed at the pump’s outlet to address this issue, and the pump was realigned. As a result, the vibration level in the outlet pipeline decreased from 16 mm/s to 12 mm/s, while the vibration level of the pump itself (5 mm/s) remained unchanged. What should be done to resolve this situation? I hope experts can give some advice
Pump and pipeline vibration problems are usually complex, involving multiple factors. Based on the information you provided, although the export pipeline has been reinforced and the vibration levels have been slightly reduced, the overall vibration level remains high, which may indicate that the root cause of the problem has not been completely resolved. Here are some possible solutions: 1. **Recheck and optimize pipeline supports**: Ensure that all supports for the pipelines are distributed evenly and appropriately, avoiding excessive concentration or insufficient support. Especially in locations where pipelines are transported over long distances or where there are bends, adding support points may help reduce vibrations. 2. **Damping treatment of pipelines**: It is possible to consider adding dampers to the pipeline system or using damping clamps, etc., which can effectively absorb and reduce vibration energy. 3. **Check the alignment of the pump and motor**: Although you have already realigned them, it is recommended to check again the accuracy of their alignment; poor alignment is a common cause of vibration. 4. **Check for wear of the pump’s internal components**: Wear or damage to components such as the impeller and bearings inside the pump can also cause vibration. Conduct internal inspections and maintenance, and replace worn parts when necessary. 5. **Hydrodynamic effects**: Analyze whether the operating conditions of the pump correspond to the design points, including flow rate and head; operation of the pump under conditions other than those designed for it can also result in additional vibration. 6. **System resonance**: Check whether resonance occurs in the system, that is, whether the system’s natural frequency is similar to or identical to the frequency of the pump or motor. The system's natural frequency can be adjusted by changing its mass or stiffness in order to avoid the excitation frequency. 7. **External influences**: Check for external factors or issues in the installation environment that may cause vibration, such as an unstable foundation. Ultimately, if the above measures still cannot completely resolve the issue, it is recommended to consult a professional vibration analyst for a more in-depth diagnostic analysis. .
Factors to consider: 1. Whether it is in a cold or hot state in Chinese style; align it according to the manufacturer’s requirements； 2. Whether the rotor dynamic balance is reasonable; 3. Whether the flow rate and density of the operating medium match the design values ； 4. Has stress-free installation of the pumps been achieved? ； 5. Is the installation of the pump foundation in compliance with standards?
Thank you, I’ll rule them out one by one according to your guidance
Learn* it a bit; let me know once there’s a result
What is the type of pump? Is the straight section of the pump outlet pipeline meeting the requirements?
Also, consider the fixing method of the foundation and equipment – whether it is rigid or flexible. Axial flow pumps use flexible foundations, and high vibration levels are a characteristic of this design