A brief description of a test executed in large expansion joints, and the application of this test systems in operation to assess damage from emergencies. After an event in a turboexpander system, visual inspections were carried out in the expansion joints of the flue gas ducts and despite the fact that the inspection did not show damage to these components, a motion field test were conducted with the system pressurized and unpressurised, and indicated severe restriction in the movement of the expansion joints. With the field tests results, it was decided to remove the expansion joints for in shop repair where new inspections and tests were performed in the factory of a manufacturer confirming the results of field. A more detailed inspection at the factory confirmed the presence of interference in the components of joints caused by excessive deformation, which confirmed the decision of removal the joint for maintenance. The movement test was confirmed as essential practical method for assessing mechanical performance of critical lines not only for new systems but also for systems that have already been in operation, which can be used in other pipeline systems and is not restricted to ducts flue gas.
Expansion joints; pipes; evaluation of failure; FCC; cold movement test
