1. Operation Failure Caused by too High Pump Head:

When the design institute selects a water pump, the pump lift is first determined through theoretical calculations, which is often somewhat conservative. As a result, the lift of the newly selected axial split case pump is higher than the lift required by the actual device, causing the pump to operate in an deviated working condition. Due to partial operating conditions, the following operating failures will occur:

1.Motor overpower (current) often occurs in centrifugal pumps.

2.Cavitation occurs in the pump, causing vibration and noise, and the outlet pressure pointer swings frequently. Due to the occurrence of cavitation, the impeller will be damaged by cavitation and the operating flow rate will decrease.

Treatment measures: Analyze theaxial split case pumpoperating data, re-determine the actual head required by the device, and adjust (reduce) the pump head. The simplest method is to cut the outer diameter of the impeller; if the cutting impeller is not enough to meet the requirements for the head reduction value, a new design can be replaced impeller; the motor can also be modified to reduce the speed to reduce the pump head.

2. The Temperature Rise of Rolling Bearing Parts Exceeds the Standard.

The maximum allowable temperature of domestic rolling bearings does not exceed 80°C. The maximum allowable temperature of imported bearings such as SKF bearings can reach 110°C. During normal operation and inspection, hand touch is used to judge whether the bearing is hot. This is an irregular judgment.

Common causes of excessive temperature of bearing components include the following:

1. Too much lubricating oil (grease);

2.  The two shafts of the machine and axial split case pump are misaligned, which puts additional load on the bearings;

3.  Component machining errors, especially the poor verticality of the end face of the bearing body and the pump seat, will also cause the bearing to be subject to additional interference forces and generate heat;

4. The pump body is interfered by the push and pull of the discharge pipe, thus destroying the concentricity of the two shafts of the axial split case pump and causing the bearings to heat up;

5. Poor bearing lubrication or grease containing mud, sand or iron filings will also cause the bearing to heat up;

6.  Insufficient bearing capacity is a problem of pump design choice. Mature products generally do not have this problem.