Suction stage impeller
The suction stage impeller is the impeller of the first stage (suction stage) of a multistage pump. In order to achieve certain suction characteristics the suction impeller's shape may differ from impellers of other stages. In particular, it may have a wider inlet cross-section. Suction stage impellers should not be confused with inducers.
See Figs. 2 to 4 Condensate pump