Comparison of Stresses in the Junctions of Shell Structures with Bolted Flange Rings

Bolted flange joints are favored across a spectrum of pressure vessel applications within diverse industries, owing to their simplicity in installation and operation. However, ensuring their structural integrity and leak-proof performance necessitates careful consideration of both operational conditions and the nature of the connected shell. Yet, the existing ASME BPV Code for flange design lacks inclusion of a leakage criterion or flexibility analysis, hindering accurate assessment of these critical characteristics. This research aims to comprehensively evaluate the integrity and leakage resilience of various shell configurations attached to flange rings. The investigation will scrutinize pivotal factors such as flange rotation and stress distribution at the flange-shell interface, leveraging diverse shell theories across three distinct flange sizes: NPS 26, 48, and 60. Additionally, four prevalent types of shell connections—cylindrical, spherical, dish, and conical—will be juxtaposed. Notably, all shell connections are directly affixed to the raised-face flange ring. To facilitate comparison and validation, these shell connections will be simulated using a versatile finite element program, augmenting the analytical approach. Noteworthy is the incorporation of the gasket's nonlinear behavior in the finite element analysis, a crucial aspect overlooked in the analytical modeling process.