Application and failure analysis of expansion joint in catalytic unit
The bellows expansion joint of catalytic unit is mainly used in the reaction and flue gas recovery system,which is used to absorb the deformation of the pipeline under the conditions of high temperature and stress,and has an irreplaceable role in the catalytic unit.The expansion joint of the two-vessel system of the catalytic unit is exposed to high temper-ature above 650℃for a long time during the operation of the unit,and there is the possibil-ity of high temperature creep failure.There is local vibration in the high temperature pipe from the third whirl to the inlet of flue gas turbine.Long-term service under harsh condi-tions such as high temperature,corrosion and vibration will accelerate the fatigue damage of the expansion joint structure and affect the safe and stable production of the catalytic unit.Therefore,it is very necessary to prevent the failure of the expansion joint of the catalytic u-nit.This paper describes the common failure forms of bellows expansion joints in catalytic unit under specific conditions and the corresponding failure prevention measures,which has a good reference and guiding significance for the long-term safe operation of expansion joints in catalytic unit.