2. Comparison of centrifugal, helical centrifugal and propeller pumps

Rotodynamic pumps are classified according to the following levels:

• impeller type: centrifugal, helical, axial;

• mode of use: horizontal, vertical, submerged, submersible... ;

• the properties of the fluid being conveyed: clear water, corrosive liquids, abrasive liquids, two-phase liquid-gas mixtures, fibrous mixtures, etc.

Each of these features corresponds to a wide variety of practical applications, giving these machines highly contrasting shapes, dimensions and technological levels. The vast majority of parts are molded. Depending on operating conditions and the nature of the fluid being pumped, the materials used will be adapted: alloy steels, chromium cast irons, ordinary cast irons. The design is of the "process" type, i.e. the rotating...