4. Multistage centrifugal pump

4.1 Components

The existence of multistage centrifugal pumps is justified by high-pressure requirements. However, there are major differences in the quality and technological level of these machines, mainly due to their unit power and the severity of their operating conditions. Figure 13 shows one such machine. This is a very conventional design, with a long shaft requiring a bearing at each end (grease-lubricated bearings). Each wheel is individually balanced for axial thrust or, alternatively, a global balancing system is used: the balancing piston. The morphology of each stage is characterized by the presence of an important hydraulic component: the diffuser-return assembly....