What is a pump? A: It is usually referred to as a pump that lifts liquid, transports liquid or increases pressure on the liquid, ie, changes the mechanical energy of the prime mover into liquid energy. Pump classification? A: The purpose of the pump varies, according to the principle of action can be divided into three categories: 1, the volume pump 2, vane pump 3, the other types of pump displacement pump works? Example? A: The use of cyclical changes in the volume of work to transport liquid. For example: piston pump, piston pump, diaphragm pump, gear pump, skateboard pump, screw pump and so on. Vane pump works? Example? A: Liquids are transported using the liquid interactions of the blades. For example: centrifugal pump, mixed flow pump, axial flow pump, whirlpool pump and so on. Centrifugal pump works? A: Centrifugal pump relies on the role of the impeller on the liquid to the prime mover mechanical energy transfer to the liquid, due to the role of centrifugal pump liquid from the impeller inlet to the outlet of the process, its speed and pressure can be increased by the impeller discharge of liquid through Out of the room most of the speed can be converted into pressure and then sent along the discharge pipe. At this time, the impeller inlet side due to the discharge of liquid to form a vacuum or low pressure, the liquid sucked in the pool liquid level pressure (atmospheric pressure), that is pressed into the impeller inlet. As a result, the rotating impeller continuously inhales and discharges the liquid.