Page 143 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

Figure 8-30
~~~
c
$3
3
*
a BEST

H EFF.
FEET
ZONE

f
Hp high

I
Hs high

Hp low
Hs low 0
0 - -
0 Q
GPM
Figure 8-31
-.
parallel and series. Notice that this system design requires 12 gate
valves, 2 check valves, 10 ‘T’ connections, and 20 elbows. Because of
the high Hf in the area of the pumps, the actual head and flow
characteristics may be less than the theoretical characteristics. It appears
as in Figure 8-30.
The same previously mentioned critical tips apply, plus one more. Upon
observing the system curve, with the pump curves, it appears that the
operator can operate any one pump, or any two, or any three or four
pumps. Actually there is no option to run three pumps in this