A question about the flow rate of shielded pumps
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I’m a beginner and would like to ask: if one knows the outlet pressure, current, and head of a canned motor pump during operation, as well as its rated current, rated flow rate, and other similar parameters, how can one calculate its flow rate while it’s in use? Is there a formula?
Is this problem difficult or not? I know that the results obtained through such calculations are inaccurate; there will likely be errors But to be honest, I’ve been searching for a long time without finding any clear formula or method. Are there any experts on the website who can help?
This post was last edited by ylb913 on 2018-10-10 at 20:23. There is no such formula; each pump comes with its own flow curve upon leaving the factory, but this can only be used as a reference. It’s common to be unable to find the cause of frequent pump tripping; sometimes it’s a problem with the inlet pipeline of the pump, and other times it’s a problem with the motor. In actual operating conditions, there are many situations that do not match the pump’s flow curve at the time of manufacture.
There are two methods: 1. Use a flow meter for measurement (something even a fool would think of). 2. Calculate the pump’s current head based on the pressure difference between the inlet and outlet, along with the specific gravity of the medium (the rated head and current values specified are based on ideal design conditions, not the actual current situation, and are provided for reference only); then use the performance curve to determine the flow rate corresponding to that head value. The first method is still accurate! :)