The problem of cavitation in centrifugal pumps
Thread Content
There are three pumps, two in operation and one as a backup. Parallel. Now that the back-pressure control valve of the pump has been opened to a certain extent, it is opened further – «at this point, the total flow rate at the outlet has already reached its limit». The flow rate of one of the pumps decreases significantly; «this happens regardless of whether this pump is operating simultaneously with any other pump». As a result, the flow rate of that pump drops, leading to cavitation. I don’t know why this is the case
It is related to the connection with the pipeline, whether it is the inlet or the outlet
Is it possible that not enough of the liquid was drawn in?
Check the pipeline for any foreign objects and for air leaks.
It is recommended that when controlling the flow rate, the motor current of the pump should be at its maximum within the rated range. The flow rate of the centrifugal pump should be controlled by an outlet valve.
The water flow will take the shortcut; there must be higher resistance in the pump inlet pipeline where cavitation occurs, as compared to those areas where no cavitation takes place
It’s related to the piping; check it.
In parallel pumps, if one of them suffers from cavitation and its efficiency decreases, this will also lead to a decrease in the efficiency of the pumps connected in parallel with it! It is recommended to repair the cavitation defect!
Just run one pump to see if the same issue occurs with that pump; generally, it’s caused by a decrease in the inflow volume