Misunderstanding about API-610 operating regions

[gilus02]

Hi,

In API-610 it has been mentioned that "Pumps shall have a preferred operating region of 70 % to 120 % of best efficiency flowrate of the pump as furnished. Rated flow shall be within the region of 80 % to 110 % of best efficiency flowrate of the pump as furnished."
For instance if a pump has BEP at 100 m3/h it shall have rated operating region between 80 m3/h and 110 m3/h and preferred operating region of 70 m3/h to 120 m3/h.
But in Annex M of API-610 ed.10th a curve is provided which deviates from this rule. In this diagram, the BEP flowrate is 188 m3/h and the following regions are defined:
130 m3/h < Preferred Operating Region < 226 m3/h
75 m3/h < Allowable Operating Region < 244 m3/h

and this regions aren't satisfying the API criteria!

A friend of mine have asked me this question and I postpone the answer till tomorrow. Could anyone help me?

Thanks!

 

[JJPellin]

This is an API copywrited document. You should not have posted it.

Johnny Pellin

 

[LittleInch]

Gilus02,

The values in the example are correct. The preferred operating region, 130 to 226 is in the range 70% to 120% of BEP..

The example also adds an allowable operating range which is simply a guide, not a requirement.

I don't understand what your problem is with this example curve.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[gilus02]

Thank you guys! I got it.

 

[mimentzos]

Very useful

 

[mimentzos]

Sorry for the above wrong reply
The correct Thread is "Gear Pump" of a1981

 

[1gibson]

Allowable operating region is minimum flow to end of curve. It is defined by the manufacturer, and *should* include the entire preferred operating region of 70-120% BEP, but does not always. Curve might end before it reaches 120% of BEP, for example.