Vibration at the outlet of the centrifugal pump
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Why does the outlet of a centrifugal pump experience vibration at a certain frequency? Is it due to the elbows in the outlet pipeline, with the liquid exiting hitting those elbows and generating a reaction force? I hope Haiyou can provide more guidance
There are two reasons for this: 1. Problems with the pump itself. It is caused by the pump’s own frequency matching the pipeline frequency, but this probability is extremely low. 2. The pipeline installation is unreasonable. Main reasons: a. The stress-free inspection during the installation of the pump pipelines was not carried out properly ； b. The pipeline design is unreasonable, failing to eliminate pipeline stress ； c. Poor construction quality.
Support means attaching a pillar at the bottom for support
What you’re describing is likely surging. Check whether there is air entering the pump inlet, ensure that all air in the pump chamber is removed before starting the pump, determine what the opening degree of the inlet valve is, and also check the opening degree of the outlet valve. Remove the air in front of the air pump and adjust the opening degree of the outlet valve to see if there is any change. When the outlet is vibrating, check whether the pointer on the outlet pressure gauge moves; if it does, it is likely due to air entering the system.
Take a picture to make a judgment. 1. If the pump operates without vibration after its inlet and outlet pipes are disconnected, it indicates that the pump is installed correctly ； 2. Consider whether there may be air in the inlet or cavitation caused by the pump, identify the root cause and take appropriate measures to address it ； 3. Excluding pump installation issues, it is possible that the inlet and outlet pipes were installed under stress ； If the pressure and medium conditions permit, soft connectors can be installed and the supports can be reinforced again ；
It is recommended to disassemble the pump’s inlet and outlet flanges during shutdown to check whether there is any misalignment of the flanges in their free state. If it is necessary to reconfigure the pipeline during shutdown to relieve stress.
It’s likely that the centrifugal pump is operating in a surge condition; check whether the outlet opening is too small
You can try reducing the flow rate to test it (this method incurs no cost). If no abnormal noises occur after reducing the flow rate, it means there is too much resistance in the pipes; in that case, you should focus on addressing the issues at the pipes and the outlet