Publications

Tube to tubesheet joint expansion is a common method that is widely applied in Air Cooled Heat Exchanger design. This method offers many advantages in the tube bundle fabrication process particularly in the fabrication speed. However, due to the exposure of the exchanger to both internal and external factors during operation, the expansion joint becomes a critical section. One of the factors is the residual stress generated at the tubesheet holes as an effect of tube expansion. The residual stress itself is affected by several factorssuch as tolerance of the tubesheet hole and percentage of the tube expansion. This evaluation succeeds in developing a finite element model using stainless steel grade 316L material and the guidance parameters provided by related standards and codes e.g. tube wall thickness ratios and tube hole tolerances. Residual stresses that are significantly higher than the Chloride Stress Corrosion Cracking (Cl-SCC) threshold stress are observed.