Fracture Failure Analysis on Safety Valve of a Generator Sealing Oil System

The gray iron safety valve of a generator sealing oil system in electric power industry fractured during installation, and series of test such as macro analysis, tensile test, metallographic examination and fracture micro analysis were done to the failure safety valve to find out the fracture reasons. The results show that the fracture of the safety valve was typical brittle fracture of gray iron. The low strength of the safety valve and improper installation process were main reasons for the brittle fracture. Finally, preventive measures were put forward.