Water-Lifting Devices – Pumps - Practices of Irrigation and On-farm Water Management - page 440

12.2.4.4 Classification Based on the Principle by Which Energy Is Added
to the Fluid

Under this system of classification, all pumps may be divided into two major
categories:

(1) Dynamic pumps - where continuously added energy increases velocity of the
fluid and later this velocity is changed to pressure, and
(2) Displacement pumps - where periodically added energy directly increases
pressure.

Dynamic Pumps

Dynamic pumps can be classified as one of several types of centrifugal pumps and
a group of special effect pumps. In centrifugal pumps, energy is imparted to a fluid
by centrifugal action often combined with propeller or lifting action. Centrifugal
pumps can be classified by impeller shape and characteristics.
With respect to type of impeller, all centrifugal pumps can be classified into three
following groups:

• Radial-flow pumps - which develop head mainly by the action of centrifugal

force.

• Axial-flow pumps - produce flow by the lifting action of the propellers or vanes.

• Mixed-flow pumps - use both centrifugal force and some lifting action.

In addition, a centrifugal pump can be classified in one of four major groups
depending on its design and application:

• Volute pumps

• Diffuser pumps

• Turbine pumps

• Propeller pumps

Turbine pump can be classified into

• Deep-well turbine pump

• Submersible turbine pump

Deep-well turbine pump can be further divided into

• Single stage

• Multistage

Single-stage pump have one impeller in one case. In multistage pump, two or more
impellers enclosed in one casing to increase pressure (like pumps connected in