On the Use of Theory of Rings on Non-Linear Elastic Foundation to Study the Effect of Bolt Spacing in Bolted Flange Joints

Abstract

Bolted flange joints are extensively used to connect pressure vessels and piping equipment together. They are simple structures that offer the possibility of disassembly. However, they often experience leakage problems due to a loss of tightness as a result of a non-uniform distribution of gasket contact stresses in the radial and circumferential direction. Many factors contribute to such a failure; the flange and gasket stiffness and bolt spacing design combination being one of them. In our recent paper the effects of bolt spacing was investigated based on the theory of circular beams resting on a linear elastic foundation [1]. This paper is an extension of the work in which an analytical solution based on the true gasket non-linear behavior is developed. The study focuses on the distribution of the gasket contact stress of two large diameter flanges namely a 52 and a 120 in heat exchanger flanges. The non-linear gasket behavior solution is compared to the FEA and the linear gasket behavior solution for evaluation and validation.