Page 107 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

-200
-190
-180
-170
-160
-150
-140

a
-130 IC1
-120 2
c
.- -110 .-
c
a
a -100 Q
a
Q -90 =
a
r -
-
Q
.I-
Q -80 I-0
.I-
I-0 -
70
- 60
-
50
-40
-
30
- 20
- 10
-0
i

Fiaure 7-17

Although the pump is not part of this discussion, we present a curve of
a positive displacement (PD) pump (Figure 7-17).
On seeing and examining these different pump curves, notice that all
curves contrast head and flow. And, in every case the head is decreasing
as the flow increases.

Except for the curve of the PD pump, the other pump curves show
various diameter impellers that can be used within the pump volute.
And, on all these family curves, the efficiencies are seen as concentric
ellipses. There is very little variation in the presentation of the BHp and