General
Boiler feed water pump can transport high temperature water below 280 °C, suitable for boiler feed water, factory and city water supply. It is widely used in boiler feed water and urban living water supply for industrial and mining enterprises and institutions. DG series pumps are especially suitable for boiler feed water, and can also be widely used in pressure vessel water supply, hot water circulation, high-rise building water supply, farmland irrigation, fire boosting, water washing, food, brewing, medicine, chemical, aquaculture, environmental protection and other industries.

According to the structure, it can be divided into two types:
1. The inlet and outlet are located at the two ends of the pump, respectively, called the conventional multi-stage boiler feed pump.
2. The outlet is located on one side and the inlet is located in the center of the horizontal line of the pump. It is called a self-balancing multi-stage boiler feed pump.

Working principal
The pump shaft rotates under the driving of the motor, and works on the liquid to increase its energy. The liquid is taken from the pool through the suction stage, the positive impeller, the positive guide vane, the middle stage, the mouth, the transition tube, the secondary suction stage, the negative impeller, the negative guide vane and finally the discharge stage.

Structure
The inlet and outlet of boiler feed pump are all vertically upwards. The pump is mainly
consist of the suction stage, the middle stage, the discharge stage, the secondary suction
stage, the positive guide vane, the negative impeller, the shaft, the throttling and pressure reducing device, the retaining sleeve, the bearing body, the transition tube.
The middle stage is connected by high-strength wear bolts and suction and discharge stages. The sealing surfaces of the suction, middle and discharge stage of the pump are hard-sealed with molybdenum disulfide grease metal surface.
The rotor consists of a positive impeller, a throttle decompression device, a negative impeller, a bushing, and a bearing retaining sleeve all mounted on the shaft. The bearing adopts “solid oil” dry oil lubrication structure, the drive end adopts cylindrical rolling on the bearing, and the end adopts angular contact ball bearing.
A sealing ring and a vane sleeve are installed between the rotor portion and the fixed portion for sealing. When the the sealing ring and the vane sleeve have been wearing which has affected the working performance of the pump, it should be replaced.