Behavior of bolted joints with metal-to-metal contact type gaskets under bolting-up and loading conditions

Abstract

A floating-type joint applies the entire bolt load to the gasket to generate sealing contact stress, and is prone to leak due to the bolt load loss. Different with the floating type one, a metal-to-metal contact type joint applies only part of the bolt load to the gasket to achieve seating stress, and applies the additional bolt load to the metal-to-metal contact to compensate for the unloading effects due to internal and external loadings. Due to this advantage, metal-to-metal contact type joints are gradually used in chemical industries, nuclear power industries, etc. A flange joint together with a metal-to-metal contact type gasket forms the metal-to-metal contact type joint studied in this article. A threedimensional nonlinear finite element model is developed to highlight the complex behavior of the flange joint under bolting-up, pressure loading and thermal loading conditions. Despite the common perception that gasket stress in a metal-to-metal contact type joint stays constant, reduced gasket stress is concluded due to flange rotation and joint thermal expansion.

Effect of thermal loading on sealing behavior of single and twin-gasketed flange joints

“…The residual stress line defines the minimum gasket contact stress required to avoid leakage of internal fluid from the gasketed joint. The minimum compressive gasket contact stress equation for single-gasketed joint (RSL_SG), to maintain tight seal provided by ASME code 17 is given by equation (1). It is dependent on the gasket material.…”

“…Considerable work was done on the performance of gasketed flange joint under operating conditions. Ma et al 1 worked on the behavior of metal-to-metal contact type gasketed joints (MMCG) under loading conditions. They have used the temperature-dependent properties of metal-to-metal type gasket.…”

Study on the gasket parameters and the calculation of MMC flange joint according to XP CEN\TS 1591-3

“…After determining the elastic modulus E G of gasket, the elasticity modulus E 0 of gasket with zero compression for different stress sections and the change ratio of elastic modulus E G can be calculated according to equation (1). The results are shown in Table 4.…”

“…The structure features, sealing mechanism, and advantages of MMC type flange joints can be found in various literatures. [1][2][3][4][5] BS EN 1591-1 6 stipulates the design method based on leakage for floating type flange joints, and the gasket parameters used in BS EN 1591-1 are given in BS EN 1591-2. 7 The corresponding test methods are presented in EN13555.…”

Behavior of gasketed bolted pipe flange joint under combined internal pressure, axial, and bending load: Three-dimensional numerical study

“…More recently, joint behavior of bolted flange joints are performed in various studies. [13][14][15][16][17][18][19][20][21][22] Most of these research focuses on the effect of sequence of bolt-tightening and loading of internal pressure only while the impact of combination of internal pressure, axial loading, and bending load, on the joint is observed to be limited. The impact of bending load in combination with internal pressure and axial load, is more important in case of the offshore heavy structures, and might contribute significantly in the catastrophic failure of the joint.…”