Expansion joints are used in the various locations of the ducts carrying the gas at high pressure and temperature. These joints absorb vibrations due to flow of gas and also absorb dimensional variations of ducts due to pressure and thermal expansion. Failure of expansion joint has been observed. Sleeve of the expansion joint is failing, and because of this failure, bellows directly exposed to hot gases are also failing. A Finite Element Analysis (FEA) is carried out to investigate the causes of failure.

An expansion joint can be defined as a device containing one or more bellows used to absorb dimensional changes in the pipe line, duct or vessel caused by thermal expansion and contraction. The main function of expansion joint is to provide flexibility in the piping in order to compensate variations in length. The expansion joint possesses several advantages over conventional compensating devices such as capable of absorbing any movement, compact arrangement and maintenance free long life. The function of expansion joints in various applications is to provide flexibility in the piping. The performance of expansion joint mainly depends on the design of bellows. The whole assembly of expansion joint consists of other elements like liner, flanges, sleeve, cover, collar, control rods, limit rod, etc. Bellow is welded with the collar and collar material, which is further welded with the flanges. Generally expansion joints are manufactured along with flanges in order to facilitate the assembly in long piping. The flanges are connected with flanges of pipe with fasteners.

Mechanical Engineering Journal, Expansion joint, Dynamic analysis, Sleeve, Bellow, Fatigue life.