minimum allowable flow for centrifugal pump with inverter 2

[amazing azza]

Hello friends, is there any rule of thumb for calculating a minimum flow for an inverter controlled centrifugal pump?

How could one determine this value? My confusion comes from this: given a frequency you can probably find the minimum flow by restricting the outlet valve and watching for noise/temperature. But then again, you could just reduce the frequency without closing the outlet valve and achieve the same flow reduction...

 

[waross]

In skid mounted equipment the distances to the first reflection point (90 bend, valve or other restriction) are generally so short that forbidden frequencies are not encountered.

Bill
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