The original water pump shaft fracture accident analysis

2019 - the original water pump shaft fracture accident analysis 03 - 11 ( Zhongtong pump industry association branch) A, description of equipment: equipment name: the original water pump equipment models: GC80 - 200 head: 50 m flow 100 m & sup3; / h shaft power: 22. 2 kw speed: 2950 r/min manufacturer: liaoning Greg, pump industry co. , LTD. Second, the accident process: on April 26, 2018, 10 points for production water supply demand increases, the need to increase the original water. In the existing raw water pump (B Traffic: 200 m & sup3; /小时) Cases increase the raw water pump (A Traffic: 100 m & sup3; /小时) 。 Arrived at the scene after turning without jamming phenomenon, check after kai pump found in the process of raw water pump outlet pressure, after contact maintenance unit on-site inspection. Three, processing was: to solve the problem of the equipment failure on April 26 13:00 to overhaul of the pump, overhaul situation is as follows: 1. The section for the new and old part 2. 2. From the point of the cylindrical section, all is the old fault trace. 3. Bearings, machine is not found damage phenomenon. 4. Can be seen from the impeller blade cavitation phenomenon exists. 5. Coupling bolts, the impeller back caps connecting bolts are loose. 6. The entrance no foreign body was found. 7. DCS data to be obtained, A raw water pump overload and other anomalies. Four, cause analysis: 1, the material existence of stress concentration, long run lead to crack of axle shaft fracture cause. 2, shaft heat treatment is not good, no modulation processing. There are some internal defects in 3, the material itself. 4, cause impeller cavitation erosion leads to failure of dynamic balance, causing fatigue fracture spindle weak positions. Five, treatment recommendations: contact manufacturer or related testing unit testing analysis of spindle material, etc.