Pump is associated with industrial development and the development of follow up. In the 19th century, foreign countries have a relatively complete pump types and varieties, and has been widely used. According to statistics, around 1880, production of general purpose centrifugal pump more than 90% of the whole production, and power plant pumps, chemical pumps, mining pumps and other special-purpose pump, only about 10% of the pump output. By 1960, the general-purpose pump only 45Y002Ea, and special purpose pumps accounted for 55% o2Ea.
　　
According to current trends, special purpose pumps, will also progress than the proportion of general-purpose pump. In the early 20th century, submersible sewage pumps first developed by the United States, use it instead of deep-well pump. Then, after another Western European countries were also developed, and continues to be improved, and gradually improve. Such as the Rhine brown coal in Germany, using a variety of submersible sewage pump more than 2,500 units, up to a maximum capacity of 1600kW, lift 410m. Our submersible sewage pump is the 1960s, developed, where homework is already in the south side of submersible pumps used to irrigate farmland, and small and medium-capacity submersible pump has formed a series, and put the bulk production. Large-capacity high-voltage submersible pumps, submersible electric motor is also available after another, 500 ~ 1200kw large submersible pumps have been put into operation at the mine.
　　
Usually used to suction fluid, transmission fluid and the liquid to increase the pressure of the machine referred to as the pump. From the energy point of view, the pump is an energy conversion machine, it is the original idea of the mechanical energy is converted to energy transmission fluid, so that the flow rate and pressure of the liquid increases. Pump is generally used the liquid pumped up from the low-lying areas along the pipeline transportation to go to higher ground.
　　
For example, we see every day, with the pump to the river, pond water pumping on between farmland irrigation; and if the underground water in deep wells pumping up and sent to the towers go up and so on. Because the liquid through the pump pressure may be progressive, so that the role of the pump can also be used to pump out the liquid from the lower pressure of the vessel, and to overcome the resistance along the conveyor to the higher pressure vessel or elsewhere required, e.g. boiler feed pump pumping water from the low-pressure tank to the higher pressure of boiler feed water.
　　
Wide performance range of the pump, the pump flow rate can be as large giant hundreds of thousands in / h or more; and miniature pump flow is in the tens of mL / h or less. Which may be from atmospheric pressure up to l000MPa been above. It is the lowest temperature of the liquid can be transported to ~ 200 ° C or less, up to 800 ° C and above. Many types of pumping liquid, which can deliver water (clean water, sewage, etc.), oil, acid, emulsions, suspensions, and liquid metals.