The main flow parts  are suction chamber, impeller and pumping chamber. The suction chamber is located in the front of impeller inlet, having the effect of guiding the medium to the impeller; The pumping chamber  is of semi- spiral pumping(volute) form; The impeller pump is one of the most important component, is the heart of the flow components, it is composed of cover plate and blade. 

Before the pump is operating, it shall be full of medium first. And then the pump is started, the impeller will rapidly rotate. The impeller blades drive the medium to rotate. During rotating, the medium flows towards the outer edge of the impeller due to inertia, at the same time, the impeller sucks medium from the suction chamber. 

During this process, the medium of the impeller flows around the blades. During streaming, the medium role of lift force is greater than the blade, on the contrary, the blade acts on the medium with a force equal to the lift force and in opposite direction, this force works on the medium, so that the medium is energized and flows out from the impeller, at this moment the function and pressure energy of the medium are both increased. 

The pump depends on the function of rotating impeller on the medium, to transfer the mechanical energy of prime motor to the medium. Due to the action of the pump, during the process of flowing from the impeller inlet to the outlet, the gas speed and the pressure of the medium can be increased. The medium drained from the impeller passes through the pumping room, the most speed of the medium can be converted to pressure energy and the medium can be conveyed along the discharge pipe, at this moment, the vacuum or low pressure occurs at the inlet of the impeller due to the draining of the discharging of the medium. Under the function of the liquid surface pressure (atmospheric pressure), the medium of the suction chamber is pressurized into the inlet of the impeller, so that the rotating impeller is continuously sucking and discharging the medium.