Page 74 - Centrifugal Pumps Design and Application

Volute Design 57

Figure 5-4. Efficiency comparison of circular and conventional volutes,

has shown that these do not have a significant effect on casing losses. The
following design rules have shown themselves to be applicable to all cas-
ing designs:

1. Constant angles on the volute sidewalls should be used rather than
different angles at each volute section. Experience has shown that
these two approaches give as good results and the use of constant
wall angles reduces pattern costs and saves manufacturing time.
2. The volute space on both sides of the impeller shrouds should be
symmetrical.