Problems with shielded pumps
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Our factory has a shielded pump. When the pump delivers a high flow rate, the TRG pointer moves into the yellow zone; when the outlet valve is opened slightly more, reducing the flow rate, the pointer returns to the green zone. What’s causing this?
The vibration of the pump is also related to the process flow rate to a certain extent. Vibration levels are high when the flow rate is not in the optimal range; TRG is a bearing monitor that indicates that the pump’s flow rate has deviated too much from the BEP point. It’s possible that the pump selected is too small
This pump has a rated flow rate of 440; when the flow rate is at 390, it is in the yellow zone, and when it is at 330, it is in the green zone
It is necessary to check what the flow rate at the BEP point (the point of maximum efficiency) is, in order to determine whether there are any issues with the pump selection. Is there a performance curve for the pump?
Details such as flow rate, head, installation, etc. need to be described in detail
First, confirm whether cavitation vibration is present, and then check whether the pump is operating at its optimal point. Are they new pumps or the original ones that were working fine?
It is best to check the bearings, the axial clearance and bearing clearance, and then perform dynamic balancing on the rotor to verify its runout
Calculate the inlet flow velocity of the pump at 390. Generally, the inlet flow velocity of a centrifugal pump should not exceed 2 m/s; if the inlet pipe for the pump is not selected appropriately, the vibration of the pump will increase.
There are differences between the parameters on the nameplate and the actual conditions on site; factors such as the pressure and temperature at the pump inlet play a role in this
Add me on QQ at 79753774; I’ll send you the details and you’ll understand