FAILURE ANALYSIS OF EXPANSION JOINT IN FCC AND REMEDIAL MEASURE
催化裂化装置膨胀节失效原因与措施

In order to understand the history of failures of expansion joints made of stainless steel 316L in fluid catalytic cracking(FCC) of Dalian Petrochemical Corporation,an analysis was performed by means of various techniques including EDX and SEM examinations.The results showed that the temperature of expansion joints was in the range of sensitizing temperature of steel 316L, the magnitude of residual stress in expansion joint and special corrosive media are main factors of failure of the expansion joints. At last, according to operating conditions,a sovereign remedy is to replace expansion joint by a packed slip joint. It is proved that the packed slip joint can act not only as proper compensator for thermal expansion, but also avoid SCC. This remedial measure may be recommended to apply to other FCC.