Three-Dimensional Finite Element Analysis of Pipe Flange Connections(In Case of Using Compressed Asbestos Sheet Gasket)

Abstract

The most important factors for the leakage problem of pipe flange connection is considered to be contact pressure distribution at the gasket bearing surface in service. In this study, the mechanical behaviors of pipe flange connection are evaluated using FEM as a three-dimensional contact problem, in which a gasket is modeled as a nonlinear one-dimensional gasket element. Here, the contact pressure distributions at the gasket bearing surface and the variations of bolt stress are estimated under uniform bolt preloads or nonuniform ones due to the elastic interaction during bolting up. The numerical procedure proposed here can successively deal with the processes of bolt-up, applying inner pressure and applying bending moment. The analytical objects are pipe flanges specified in JIS B 2238 with compressed asbestos sheet gaskets being inserted. The validity of the numerical method is ascertained by experiment.