Methodical Guideline for Bolt-Up Operation of Pipe Flange Connections (A Case Using Sheet Gasket and Spiral Wound Gasket)

摘要

The purpose of this study is the proposal of guidelines for bolt-up operation of pipe flange connections with joint sheet gasket or spiral wound gasket. Numerical calculations are systematically executed for pipe flanges with wide variety of nominal size by using finite element analysis, which can simulate the bolt-up process of a pipe flange connection, because the tightening performance of the pipe flange connection largely depends on the bolt-up process. Gaskets also have dominant effects on the tightening performance. It is, however, impossible to determine the number of tightening passes to get uniform bolt preloads for all kinds of gaskets. A simplified modeling method of nonlinear stress-strain relationship of gasket is, therefore, evaluated and a representative material property of gasket is selected to develop the bolt assembly guideline. The bolt-up procedure, in which four bolts located 90 degrees from each other are tightened with the same magnitude of preload at the installation process, is investigated.