Analysis of multistage pump shaft fracture

Aiming at the fracture accident of overseas multistage high-pressured hydrocarbon pump shaft which is bringed in some chemical enterprise, by combining the shaft materials and fracture appearance, and using mechanical reliability design theory and methods we calculate and analyze the main fracture reasons. The calculated results show that the pump selection head is too high, making the shaft with a large integrated working stress. In addition there exists local stress concentration, together with chloride ion corrosion, so the shaft reliability is lower, leading to fatigue failure and fracture. Accordingly, the corresponding improved measures are proposed.