Finite Element Method Stress Analysis and Evaluation of the Sealing Performance in Box-Shape Flange Gasketed Connections Subjected to Internal Pressure

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Toshiyuki Sawa ◽  
Kentaro Tenma ◽  
Takashi Kobayashi ◽  
Ryou Kurosawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Displacement Curve ◽  
Stress Distributions ◽  
Analysis And Evaluation ◽  
Gas Leakage ◽  
Sealing Performance ◽  
Cover Thickness ◽  
Element Method

Bolted connections inserting gaskets such as box-shape flange connections have been widely used in mechanical structures, nuclear and chemical industry, and so on. They are usually used under internal pressure. In designing the box-shape flange connections with gaskets under internal pressure, it is important to clarify the gasket stress distribution for evaluating the sealing performance of these connections. However, no research in which the sealing performance of these connections is examined under internal pressure has been carried out. Thus, the design for box-shape connection such as thickness of flange cover, number of bolts, gasket width, and so on is not clarified. In this paper, the contact gasket stresses of these connections under internal pressure are analyzed using the finite element method (FEM), taking into account a hysteresis in the stress–displacement curve of the gasket. And then, using the contact gasket stress distributions obtained from FE analysis and the relationship between gasket stress and leak rate obtained from a gasket sealing test (JIS B2490), a method for estimating an amount of leakage is examined. Leakage tests were also conducted to measure an amount of gas leakage using an actual box-shape flange connection with a gasket. The estimated results are in reasonable agreement with the experimental results. In addition, the effect of gasket width, flange cover thickness, and flange cover material is examined on the sealing performances of box-shape flange connections under internal pressure. The effects of the above factors are discussed on the sealing performance in designing box-shape flange connections.

FEM Stress Analysis and Evaluation of the Sealing Performance in Box-Shape Flange Gasketed Connections Subjected to Internal Pressure

2010 ◽  
Author(s):  
Kentaro Tenma ◽  
Ryou Kurosawa ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Displacement Curve ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Analysis And Evaluation ◽  
Gas Leakage ◽  
Sealing Performance ◽  
Cover Thickness ◽  
The Relationship ◽  
Cover Material

Bolted connections inserting gaskets such as box-shape flange connections have been widely used in mechanical structures, nuclear and chemical industry, and so on. They are usually used under internal pressure. In designing the box-shape flange connections with gaskets under internal pressure, it is important to clarify the gasket stress distribution for evaluating the sealing performance of these connections. However, no research in which the sealing performance of these connections is examined under internal pressure has been carried out. Thus, the design for box-shape connection such as thickness of flange cover, number of bolts, gasket width and so on is not clarified. In this paper, the contact gasket stresses of these connections under internal pressure are analyzed using the finite element method (FEM), taking into account a hysteresis in the stress-displacement curve of the gasket. And then, using the contact gasket stress distributions obtained from FE analysis and the relationship between gasket stress and leak rate obtained from a gasket sealing test (JIS B2490), method for estimating an amount of leakage is examined. The leakage tests were also conducted to measure an amount of gas leakage using an actual box-shape flange connection with a gasket. The estimated results are in a fairly good agreement with the experimental results. In addition, the effect of gasket width, flange cover thickness and flange cover material is examined on the sealing performances of box-shape flange connections under internal pressure. The effects of the above factors are discussed on the sealing performance in designing box-shape flange connections.

Effects of Scatter in Bolt Preload of Pipe Flange Connections With Gaskets on Sealing Performance

2003 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Mitsuhiro Matsumoto ◽  
Satoshi Nagata
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Control Method ◽  
Torque Control ◽  
Stress Distributions ◽  
Flange Connection ◽  
Gas Leakage ◽  
Bolt Preload ◽  
Sealing Performance

It has been well known that a scatter in axial bolt forces of pipe flange connections tightened by the torque control method is substantial. It is necessary for evaluating the sealing performance of the pipe flange connections with the gaskets subjected to intemal pressure to know the contact gasket stress distributions due to the scatter of the axial bolt forces in the connections tightened by the torque control method. This paper deals with the leakage of the pipe flange connections with a spiral wound gasket and that with a compressed sheet gasket tightened by the torque control method. The scatter in the axial bolt forces was measured in the experiments. The contact gasket stress distributions at the interfaces of the pipe flange connections with the gaskets were calculated under the measured axial bolt forces by using elasto-plastic finite element method (FEM) taking into account hysteresis and non-linearity in the stress-strain curves of the gaskets. The effects of the scatter in the axial bolt forces tightened by the torque control method on the gas leakage were also examined by using the actual pipe flange connections. As the result, a difference in an amount of gas leakage measured was found to be substantial between our study and PVRC procedure. By using the calculated contact gasket stress distributions under the internal pressure and the results of the leakage tests, the sealing performance was evaluated. It is found that the sealing performance is worse in the actual pipe flange connection than that evaluated by PVRC procedure.

FEM Stress Analysis and Sealing Performance in Non-Circular Flange Connections With Gaskets Subjected to Internal Pressure

2003 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Wataru Maezaki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Stress Distributions ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Element Method

The contact gasket stress distributions of a non-circular flange connection with a compressed asbestos sheet gasket subjected to internal pressure were analyzed taking account a hysteresis of the gasket by using finite element method (FEM). Leakage tests were also conducted using an actual non-circular flange connection with a compressed asbestos sheet gasket under internal pressure. By using the contact gasket stress distributions and the results of the leakage tests, the new gasket constants were calculated. A difference in the new gasket constants between the values obtained from the present study and those by the PVRC procedure was substantial. In addition, a method to determine the initial clamping bolt force (bolt preload) for a given tightness parameter was demonstrated. abstract text here.

FEM Analysis and an Evaluation of the Sealing Performance in Flexible Box-Shape Flanged Bolted Joints With Gaskets Subjected to Internal Pressure

2006 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Ryo Kurosawa ◽  
Yasuaki Tatsumi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Fem Analysis ◽  
Bolted Joints ◽  
Stress Distributions ◽  
Bolt Preload ◽  
Sealing Performance ◽  
The Difference ◽  
Element Method

The contact gasket stress distributions of rectangular box-shape flange connections with compressed joint sheet gaskets subjected to internal pressure were analyzed taking account hysteresis of the gaskets using finite element method (FEM). Leakage tests were also conducted using actual rectangular box-shape flange connections with compressed joint sheet gaskets under internal pressure. By using the contact gasket stress distributions and the results of the leakage tests, the new gasket constants were calculated. The difference in the new gasket constants between the values obtained from the present study and those by the PVRC procedure was substantial. In addition, a method to determine the initial clamping bolt force (bolt preload) for a given tightness parameter was demonstrated.

Stress Analysis and the Sealing Performance Evaluation of Pipe Flange Connections With Gaskets Subjected to Internal Pressure and External Bending Moment: Effects of Scatter in Bolt Preload

2004 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Wataru Maezaki ◽  
Satoshi Nagata
Keyword(s):  
Finite Element Method ◽  
Internal Pressure ◽  
Control Method ◽  
Bending Moment ◽  
Torque Control ◽  
Stress Distributions ◽  
Gas Leakage ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Spiral Wound

It has been well known that a scatter in axial bolt forces of pipe flange connections tightened by the torque control method is substantial. It is necessary for evaluating the sealing performance of the pipe flange connections with the gaskets subjected to internal pressure and external bending moment to know the contact gasket stress distributions due to the scatter of the axial bolt forces in the connections tightened by the torque control method. This paper deals with the leakage of the pipe flange connections with a spiral wound gasket subjected to internal pressure and external bending moment tightened by the torque control method. The scattered axial bolt forces were measured in the experiments. The contact gasket stress distributions at the interfaces between pipe flanges and the gasket were calculated under the measured axial bolt force by using elasto-plastic finite element method (FEM) taking into account hysteresis and non-linearity in the stress-strain curves of spiral wound gasket. The effects of the scatter in the axial bolt forces tightened by the torque control method on the gas leakage were also examined by using the actual pipe flange connections under internal pressure and external bending moment. By using the calculated contact stress distributions and the results of the leakage tests, the sealing performance was evaluated. It is found that the sealing performance is worse in the actual pipe flange connection than that evaluated by PVRC procedure.

FEM Calculation and Evaluation of Sealing Performance in Oil Pan Wavy-Shaped Flange Gasketed Connections

2011 ◽  
Author(s):  
Ryou Kurosawa ◽  
Kentaro Tenma ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Design Method ◽  
Light Weight ◽  
Stress Distributions ◽  
Flange Connection ◽  
Sealing Performance ◽  
Bolt Spacing ◽  
Good Agreement

The oil pan wavy-shaped flange connection, while is a type of the box-shaped flange connections, has been used for the oil-pan in the vehicles such as cars and motorcycles to seal inner fluid. Though the light weight of these connections is important, the design method has not been established, since no research for evaluating the sealing performance of the wavy-shaped flange connections has been conducted. In this paper, The contact gasket stress distribution in a oil pan wavy-shaped flange connection under the internal pressure is examined taking into account a gasket hysteresis using finite element method (FEM) for estimating a location where a principal leakage occurs and for calculating the amount of leakage. Leakage tests were also conducted to validate the estimated results using an actual connection under internal pressure. The effects of flange shape and difference in types of inner fluid (gas / liquid) are examined on the contact gasket stress distributions and the sealing performance in the connections. It is found that the estimated amount of leakage is in a fairly good agreement with the measured results. Furthermore, discussion on the effect of the bolt spacing and the gasket width on the sealing performance are made.

Axisymmetrical FEM Analysis and Estimation of the Sealing Performance in Pipe Flange Connections Combining Metallic Gasket With Adhesive Subjected to Internal Pressure and Temperature Change

2002 ◽  
Author(s):  
Masahide Katsuo ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Temperature ◽  
Internal Pressure ◽  
Temperature Change ◽  
Fem Analysis ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Sealing Performance ◽  
Moderately High Temperature

This study deals with the stress analysis and the estimation of the sealing performance of the pipe flange connections combining a metallic gasket with an adhesive subjected to an internal pressure and a temperature change. Stress distributions at the interface between the adherends and the adhesive in the connections are analyzed by using the finite element method (FEM). From the numerical calculations, the following results are obtained: (1) the stress distributes uniformly at the interface except near the edges, (2) the stress increases as Young’s modulus of an adhesive decreases, (3) the stress becomes singular at the edges of the interfaces. In the experiments, the pipe flange connections consisting of dissimilar circular gaskets with an adhesive were manufactured, and the leakage tests of the connections were carried out by applying an internal pressure and a temperature change to the connections. From the experimental results, the following results were obtained: (1) the sealing performance increased as the width of a gasket decreased and the initial clamping stress increased, and (2) the sealing performance of the pipe flange connections subjected to a temperature change increased under a moderately high temperature.

FEM Stress Analysis and an Evaluation of the Sealing Performance in Non-Circular Flange Connections With Gaskets Subjected to Internal Pressure

2006 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Ryo Kurosawa ◽  
Wataru Maezaki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
The Difference

The contact gasket stress distributions of a non-circular flange connection with a compressed sheet gasket subjected to internal pressure were analyzed taking into account of the hysteresis behavior of the gasket by using the finite element method (FEM). Leakage tests were also conducted using an actual non-circular flange connection with a compressed sheet gasket under internal pressure. Using the contact gasket stress distributions and the results of the leakage tests, the new gasket constants were calculated. The difference in the new gasket constants between the values obtained from the present study and those by the PVRC procedure was substantial. In addition, a method to determine the initial clamping bolt force (bolt preload) for a given tightness parameter was demonstrated.

Finite Element Stress Analysis and Estimation of the Sealing Performance in Pipe Fittings With PTFE Tape for Threaded Connections Under Internal Pressure

2004 ◽  
Author(s):  
Mitsutoshi Ishimura ◽  
Masahide Katsuo ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Finite Element Stress Analysis ◽  
Leakage Test ◽  
Threaded Connections ◽  
Sealing Performance ◽  
Pipe Fittings

The interface stress distributions between the unsintered PTFE (Polytetrafluoroethlene) tape and threads of the fittings under an internal pressure are analyzed by using the finite element method (FEM). From the numerical calculations, the following results were obtained: (1) the stress distributes uniformly at the interface except near the edges, (2) the stress becomes singular at the edges of the interfaces and (3) the stress increases as the Young’s modulus of the PTFE tape thickness increases. The experiment of the leakage test of the connections consist of the socket and the plug manufactured of cast iron or stainless steel, which was also carried out by applying an internal oil pressure to the threaded connections. From the experiments, the following results are obtained: (1) the sealing performance in pipe fittings with PTFE tape increased as the number of turns in the PTFE tape increased, and it was not proportional to the numbers of turns, and (2) also as the number of turns in the screw plug increased, and it became a quadratic form, (3) the flow rate of leakage oil from the fittings under the internal pressure decreased as the number of turns in the screw plug increased, and (4) it could be estimated by using the Darcy-Weisbach and the Hagen-Poiseuille equations in the laminar-flow.

Stress Analysis and Sealing Performance Evaluation in Non-Circular Flange Connections With Gaskets Subjected to Internal Pressure

2004 ◽  
Author(s):  
Wataru Maezaki ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Performance Evaluation ◽  
Internal Pressure ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
The Difference

The contact gasket stress distributions of a non-circular flange connection with a compressed asbestos sheet gasket subjected to internal pressure were analyzed taking into account of the hysteresis behaviors of the gasket by using the finite element method (FEM). Leakage tests were also conducted using an actual non-circular flange connection with a compressed asbestos sheet gasket under internal pressure. Using the contact gasket stress distributions and the results of the leakage tests, the new gasket constants were calculated. The difference in the new gasket constants between the values obtained from the present study and those by the PVRC procedure was substantial. In addition, a method to determine the initial clamping bolt force (bolt preload) for a given tightness parameter was demonstrated.

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