During the daily operation of a multistage centrifugal pump, the pump shaft may suddenly fail to rotate, and the cause of the problem must be identified before the fault can be eliminated. Analysis can be conducted from the aspects of work, user, and process. The reason for the failure is that the multistage pump itself is a long and slender shaft, and slight matching errors in assembly, processing, or design tolerances can cause phenomena such as the pump shaft not rotating after starting. The following small article from Changsha Zhonglian Pump Industry will share with you some of the reasons that cause the pump shaft of a multistage centrifugal pump to fail to rotate, for the reference of our users.
Production causes of the horizontal multistage pump shaft failing to rotate:
1、Firstly, it is due to the assembly of the horizontal multistage pump itself, which causes friction due to several parts of the pump shaft getting stuck.
2、Due to the design defects of the components of the horizontal multistage pump, the clearance is too small, which causes problems caused by a single shaft component. Moreover, many components have been installed after the shaft is stuck.
3、During assembly, the horizontal multistage pump needs to be struck with a hammer or mallet due to the needs of the components. If the installer does not pay attention to using a rubber pad or copper pad to strike the parts, then damage to the parts may be caused. Because these parts are all finished parts, all processed parts should be handled with care to avoid collisions.
4、The dynamic and static balance treatment of the rotor components is unqualified. After the entire horizontal multistage pump is installed, the entire rotor causes friction with guide blades, housings, and so on in the process of high-speed rotation which results in difficulties with the rotation of the shaft.
User site causes of the horizontal multistage pump shaft failing to rotate:
1、Firstly, the main impeller at the inlet of the horizontal multistage pump is stuck by foreign objects, causing the shaft to be unable to rotate.
2、Lack of oil in the bearing results in the burnout of the bearing and the fixation of the shaft.
3、Rust on the impeller causes the shaft to be locked.
4、The starting torque is too small, resulting in the shaft failing to rotate.
5、Improper material selection will cause the shaft to rust and seize, and damage other components.