The function of the pump body
The pump body is a volute that contains and transports liquid. It consists of a pump cover and a cochlear body. The pump case is a fixed part. The pump body is the suction chamber of the pump. Its main function is to guide the water in the suction pipe to the impeller with the minimum loss. According to the structure, the suction chamber can be divided into straight conical suction chamber, circular suction chamber and semi-spiral suction chamber. The cochlear body is composed of the cochlear chamber and the diffusion cone. The main function of the cochlear chamber is to collect the water flow from the impeller and to keep the flow rate constant in the cochlear chamber with the help of the continuous increase of the cross section to reduce the loss of water head. After discharged from the cochlea, the water flows into the pressure tube through the diffusible cone. The diffusion cone is used to reduce the velocity of water flow and convert some kinetic energy of the water flow into pressure energy.
Maintenance of pump body
Most of the pump bodies are cast with cast iron. Because of the mechanical or thermal stress, the cracks may occur and may be damaged by cavitation. If the damage is serious, the new body should be replaced. If the damage is light, it can be repaired and used. Check the crack, first with the hand hammer gently tapping the pump case, if there is a cracked sound, then the existing crack should be carefully searched. Inspection methods: on the surface of the first poured, and then sprinkle a layer of white powder, and then gently tap the hammer, cracks will exude kerosene infiltration of white powder, showing a black line, the crack length of truth can be found.
Weld repairs in places where there is no compression or sealing effect (such as flanges), to prevent cracks from spreading, a hole with a diameter of 3 mm can be drilled at both ends of the crack to eliminate the local stress concentration. In the place where the pressure is pressed, welding is required, and the welding of cast iron is divided into two types: cold welding and hot welding.
If the condition is limited, the connection plate cannot repair the cracks. The connecting plate can also be used to weld (a) V shape (b) X shape, and the groove of the pump housing is repaired to bear the pulling force.
It is a simple and economical way to repair the epoxy coating to repair the pump and pump body and impeller of the cavitation wear. The repair process is to remove rust by wind sand gun, and can also remove rust manually.