Page 91 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

500

1.000
SPECIFIC
SPEED (Ns)
1.500
AT FULL
IMPELLER
DIAMETER 2.000
AT BEP
2.500

3.000

0 5 6 7 8 9 10 11 12 13 14 15
IMPELLER DIAMETER
Figure 6-20
should be specified with the single volute designed casing, or the
double volute designed casing (Figure 6-20).
Some pumps are operated at or close to their best efficiency points.
Other pumps must run far to the left or right of their best efficiency

RADIAL FORCE VS. DESIGN CAPACITY
WITH A SINGLE AND DOUBLE VOLUTE

0 25 50 75 100 125 150
Yo DESIGN CAPACITY
Figure 6-21

74