Page 149 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

270"

240"

180"
Figure 9-6
~~

Figure 9-7
~. ~- ~ ~ __
The other case is when there is too much flow through the pump. The
pump is operating to the right of the BEP on its curve (Figure 9-8).
The same problem occurs, but now in the other direction. With the
severe increase in velocity through the pump, the pressures fall
dramatically in the E-F-G-H arc of the volute circle (Bernoulli's Law
says that as velocity goes up, pressure comes down). Now the shaft
deflects, or even breaks in the opposite direction ... at approximately
240" around the volute from the cutwater.