On the Characteristics of Bolted Joints with Gaskets : Stress Analysis of Metallic Gaskets with Raised Face Interposed between Pipe Flanges

Abstract

A design of bolted joints with gaskets mainly depends on experience and their sealing performance is not made clear by theoretical analyses. In this paper, discussion is made on the contact stress of bolted joints in the case where metallic gaskets with raised face are interposed between pipe flanges. The distribution of contact stresses of metallic gaskets is analyzed as a three body contact problem by using three-dimensional theory of elasticity. The effects of stiffness, thickness and position of gaskets on the distribution of contact stresses are investigated by numerical computations. Next, the force ratio of bolted joints with gaskets, that is a ratio of an increment of bolt axial force to an external load, is analyzed. Experiments on the force ratio are carried out. Then, it is shown that analytical results are in a fairly good agreement with experimental ones.