The structure of Double casing radial split multistage centrifugal pump mainly consist of suction casing, stage casing, press out casing, shaft, impeller, diffuser, seal rings, balancing device, bearing components and the outer barrel etc., Separate pump segment was assemble between the suction and discharge pump casing. The suction casing and discharge casing was tight by large bolts. The head of this pump can adjust according to increase or decrease of the number of stages. The interstages seal need be fit between each stage casing because each stage casing nee to bear the pressure, which can prevent liquid leakage to the outside. The quantity of intersatge seal and pressure will be increase if the number of stage casing added. Spacers are sealed with the pump and the pressure number of stages increases. The development of modern industry have higher requirement to multistage pump, the pump design need to develop high reliability, long life and high performance.

　　Product Features:

　　( 1 ) Axial thrust was balanced by single balance drum plus bearing or dual balance drum plus bearings thrust bearings, the residual axial thrust was born by thrust bearings .

　　( 2 ) The structure of the overall core package, short troubleshooting time .

　　( 3 ) The pump seal is mechanical seal, generally the single balanced mechanical seal was used; at higher temperatures occasions , the metal bellows were chose and acted as secondary seal.

　　( 4 ) the charging pump adopt self-flushing mode, the oil pump with high temperature of greater than 205 ℃, was flushed by the outer cooling flush liquid, wax oil etc. can be used generally.

　　The main advantage of double casing section pump have the rule of flow channel shape, the small size of casing, so the casting easier, less working hours, common equipment can be processed. Pressure receiving area between the segment and the segment is relatively small, narrow sealing surface; the seal reliability of the sealing surface is high. Also when the medium is conveyed to a high temperature, the likelihood of thermal expansion is small. So not easy to deformation, barrel stress is better, the wall thickness is relatively small, radial and axial compact size, outline small size, and weight is relatively small. Segmental double casing structure is intended to ensure that the structure is symmetry along the axis, which ensure proper concentricity when the feed pump meet thermal shock, to prevent water pump from running due to heat when parked and variable conditions most of the movement caused by uneven wear. The advantage of this structure is that the maintenance is easy, shorten the construction period , reduce leakage. In the case of spare core package, the repair work can be done quickly to restore the operation of pumps when the breakdown occurs, improving efficiency of pump unit, reducing economic losses.

　　Since the unidirectional arrangement of impeller, the axial thrust generated in the operation of the pump must be balanced in order to ensure the axial positioning of the rotor and stable operation. For the rotor of parallel arrangement impeller need to design balancing device, generally the structure of the balance disc or drum was adopted. Although the balance disc have more sensitive than the balance drum, but there are still a small seal gap, low hydraulic efficiency, prone to malfunction faults.

　　Applications

　　Double casing radial split multistage centrifugal pump have extensive applications, according to the selection of materials, different shaft seal used can be applied to the power plant boiler feed water, condensate and industrial high-pressure water equipment, petrochemical processes, large fertilizer and coal chemical process, refining high-pressure equipment feed, ethylene transport ; land and sea water injection, maritime transportation of crude oil, many areas of and steel descaling and so on.