What are the centrifugal pump types? And how it has been classified?

A. Dynamic:

1. Centrifugal: Axial (Single and Multistages - Closed and Open), Mixed (Radial - Single and Double Suction - Open, Semi-open and Closed) and Peripheral.

2. Special Effect:  Jet, Gas Lift, Hydraulic Ram and Electromagnetic.

B. Displacement:

> Reciprocating:

1. Piston Plunger (Steam and Power).

2. Diaphragm (Simplex and Multiplex).

> Rotary:

1. Single Rotor (Vane, Piston, Flexible Member, Screw and Peristaltic).

2. Multiple Rotor (Gear, Lobe, Circumferential  Piston and Screw).

centrifugal pumps can be claSSIFIED ACCORDING TO IMPELLER TO 

1-RADIAL flow impeller

2-axial flow impeller

3-mixed flow impeller which compined radial and axial flow principle

also empeller can be classified to

1-closed impeller

2-open impeller

semi open impeller

also centrifugal pump can be 

1-single stage pump

2-multi stage pump

1 by pupmp assembly , pump stages , pump imperal construction , pump suction , pump instalation ,pump flow types, 

1-RADIAL flow impeller

2-axial flow impeller

3-mixed flow impeller

centrifugal pump can be 

1-single stage pump

2-multi stage pump

In addition to above answers, here's a useful diagram to simplify its classifications:

http://www.pumps.org/content_detail.aspx?id=2212

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