Submerged pump: refers to the impeller (horizontal) center line below the liquid. Vertical single-stage single-suction cantilever centrifugal pump structure, the impeller is a semi-open impeller, the impeller suction side extension with mixing blades. With the bearing seat, bearing seat, connecting pipe connected to the hydraulic components of the pump, liquid from the discharge pipe components. Advantages: Cheap Disadvantages: As the motor on the surface, the pump in the liquid surface, the long axis of connection, and some up to a few. As the shaft is too long, resulting in swing amplitude amplification, sliding bearings commonly used in liquid pumps, so the shaft and bearing material requirements are relatively high, bearing life is short, resulting in higher maintenance frequency. Submersible pump is a submerged pump: Submersible pump was originally only the United States FE company to create. The utility model is composed of a pump body, a pump head, a connecting pipeline and a control device. The pump body comprises a shielded motor and a centrifugal pump. The motor and the centrifugal pump are coaxially connected according to a rotating shaft and externally form an integral whole with the oil sucking cover. Electric housings connected with external power supply by connecting handle, drain valve assembly for releasing pipeline pressure, pressure release valve and slide valve for regulating pressure, oil-gas separator. Advantage is that: the negative pressure self-priming oil supply into a positive pressure push-type oil supply, fundamentally changed the traditional delivery of oil products, to eliminate the gas resistance phenomenon, to solve the high temperature environment, deep irrigation, far Under the conditions of the pipeline pumps, positive displacement pumps, vane pumps and other negative pressure pump principle can not solve the problem of providing a convenient installation, maintenance-free, stable operation, low noise, low failure rate, long service life (design life of up to 10 years), save the cost of the new oil transportation equipment. Submersible pump features: 1. Positive pressure transmission, does not produce air resistance phenomenon. 2. The motor adopts the special structure of connecting type, which allows the oil to enter the motor and form a large circulation with the medium around the external pump, which effectively dissipates heat to the motor and provides bearing lubrication, improving the service life and reliability of the motor. Submersible pump is mainly used for: refinery, railway (distribution column), oil depots, airports, railway trestle, docks, factories and other fuel, hair oil place.