What to do if the head of the shielded centrifugal pump is set too high?
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The head was set too high, so I had to close the outlet valve of the pump to just one turn. To simulate the flow resistance of the system. Adjust the current to the rated value. May I ask, can data usage still work this way? Will it be the same flow rate as when the pump was originally selected?
You need to check the outlet pressure and compare it with the pump’s performance curve in order to determine the flow rate
This post was last edited by 764970655 on 2017-11-30 08:21. Is there no flow meter at the outlet? The valve opening is determined based on the data displayed by the flow meter. The flow rate of the pump has been chosen correctly; if the valve is indeed open only by one notch, as you say, the flow rate will definitely be insufficient. But if you say it can be adjusted to the rated current, that means the flow rate must have reached it. It’s better to state the details in order to analyze them!
This post was last edited by tczxs on 2017-11-30 at 08:50. It can be modified to use variable frequency control; our system has a lift height of 100 meters, and an actual pressure of 7-8 kilograms is sufficient. Using variable frequency control yields excellent results – it not only saves electricity but also reduces the incidence of failures
I adjusted it according to the rated current. There is no flow meter at the outlet.
There might be a slight deviation in the traffic volume
The outlet pressure and flow rate only need to meet the process requirements; there is no need to deliberately reach the rated current, as the pump’s head has already been set at a high level, which means more electricity will be consumed. Also, choosing a higher head value is beneficial for future technical upgrades; just keep that in mind going forward
Adjusting the outlet valve does not solve the problem; the flow rate does not reach the required level. The idea on the 4th floor is better – frequency modulation! Another approach could be to find a way to cut the impeller. To accurately determine the current and operating conditions of a shielded pump requires meticulous experimentation, and it is not possible to meet your requirements.
Cut the impeller; anyway, there’s no need for such a high head
Check how much larger it is, whether it falls within the range allowed by valve adjustment; if it’s too large, the pump needs to be replaced.