How to Determine Min/Normal/ Max Flow Rate Cetrifugal Pump Fl

[Chem2020]

I've got manufacturer pump curve. I'd like to know how to determine min/normal/max flow rate from the pump curve. It is a Centrifugal pump, BEP is given at 150 GPM. If we say 150 GPM is the capacity of the pump, what would be the min and normal flow rate (to produce pump data sheet)? Thanks for your response!

 

[Artisi]

If you post the curve, you might get an answer to your (meaningless) question.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[TenPenny]

Min, normal, and max flow rates are provided by the customer: what do you plan to do with the pump. Only you know what your min, max, and normal flows are. That's how they get on the datasheet.

The manufacturer will confirm if the pump is capable of these conditions.

 

[Artisi]

The whole thing is arse up, firstly the required normal flow should be established, then what is likely to be the max. flow demand as would the minimum requirement. A pump would then be selected to suit the requirements - not take a pump and design the requirements around it.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[LittleInch]

Ok, I agree that the pump data sheet really should be produced based on what your system needs.

however if you re-phrase this a bit and say, If I've got a pump with a BEP of 150 GPM, what are its realistic max and min flow rates, then in the total absence of real data ( the pump curve) then my finger in the wind guess is

Max flow - about 180 to 200
Min flow normally about 30% of BEP, so say 40-50 GPM

As I said - total and utter guesswork. Max flow is usually limited by end of curve / NPSH / max power of the motor issues. Min flow is the inner re-circulation which is always a bit of a vague guess, even by the vendor.

Note we often get questions here about why XYZ pump doesn't work very well and 99% of the time it's because the pump is the wrong size for the duty. So get the right pump for your duty first and foremost.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.