19 May What are the different pump types?
Pump types come in two main categories – Centrifugal Pumps and Positive Displacement Pumps as classified according to the method of how the energy is imparted to the fluid – Kinetic Energy or Positive Displacement and again each of these categories having many pump types.
Centrifugal Pump Types the Kinetic Energy type which imparts velocity energy to the pumped medium which is converted to pressure energy when discharging the pump casing and can be grouped according to several criteria, further to that a specific pump can belong to different groups. These groups can be based upon:
The impeller suction
The number of impellers
The type of volute
International industry standards
Shaft orientation
Split case orientation
Driver pump types
Positive Displacement Pump Types impart energy by mechanical displacement, these are of a lower flow range and are pulsating. PD pumps divided into two classes – reciprocating and rotary. Typical ‘PD’ pump types are:
Rotary Pump Types:
Rotary Gear Pumps
Peripheral Pumps
Screw Pumps
Gear Pumps
Rotary Lobe Pumps
Reciprocating Pump Types:
Plunger Pumps
Diaphragm Pumps
Plunger pumps have a cylinder with a reciprocating plunger. The suction and discharge valves are mounted in the head of cylinder. The suction stroke pulls the plunger back, suction valve opens and fluid is sucked into the cylinder. The discharge stroke pushes the plunger forward closing suction valve and pushing fluid out of the discharge valve.
Diaphragm pump types simply put use the plunger to pressurize either air or hydraulic fluid on one side which flexes the diaphragm which increases and decreases the volumetric area in the pumping chamber, non-return check valves ensure no back flow of the fluid.