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Pump output

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RomanKatz

Industrial
Aug 29, 2012
52
Hello friends,
I have a gear pump 1.5'' that pumps 40LMP.
I have a same pump 2'' that pumps 100LMP, under same conditions.

Is there a rule of thump to tell that increase from one diameter to another, increases output by?...

Best Regards
Roman Katz
 
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Hi,
The answer is No , affinity laws applied only to centrifugal pumps . The only thing is flow rate is proportional to rotation speed , VSD is often used for this purpose .
Pierre
 
What does the 1.5" refer to? The nominal size of the inlet and outlet?

But no - no clear ROT.

You could get close if you assume the velocity in the pipes is the same and therefore pump flow varies by the square difference. So in this case 4/2.25 x 40 = 71. Better than a wild guess, but no more accurate than that.

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Also: If you get a response it's polite to respond to it.
 
Do a google search for centrifugal pump curves and observe the different curve shapes from one pump to another. The shape of the curves (i.e. flow vs head) vary significantly for different pumps. Some curves are relatively steep, some relatively flat, and others in between. From one centrifugal pump to another, one can't generalize about the change in flow from increasing/decreasing the impeller diameters.

Edit: Thanks LI. I somehow overlooked that he's talking about gear pumps. My comments here are only relevant to centrifugal pumps and not to gear pumps.
 
don - he's talking about GEAR pumps...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
For gear pumps we cannot applier the affinity laws.


Gear pumps are used for viscous liquid or slurry, I saw flow change with the same system if the slurry was prepared with different solid contain that usual. I don not if these is your case, but some variables are different compared with centrifugal pumps

Horacio

 
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