Workshop: Expansion Joints in Piping

Expansion joints (or expansion bellows) are often added to piping systems after stress analysis identifies overstressed locations due to thermal expansion or displacement loads. In this workshop, Zdravko Ivancic presents practical examples from industry projects where expansion joints were introduced to bring systems into compliance with ASME B31.3 allowable stresses.

You will follow the actual calculation steps used to justify design changes. This includes verifying imposed axial and lateral movements, checking bellows capacity, and reassessing sustained, expansion and occasional load cases after modifications. Specific examples are discussed where the wrong type of expansion joint was initially selected—for example, axial joints installed in systems dominated by lateral displacement—resulting in continued overstress.

Particular attention is given to bellows without tie-rods and the correct treatment of pressure thrust in piping stress models. Incorrect modelling of pressure thrust is a frequent cause of review comments and field problems. The course also addresses recurring practical issues: improper supporting, failure to follow installation procedures, insufficient protection during construction, and lack of inspection and maintenance. The emphasis is on calculation, modelling discipline and engineering judgement.