FEM Stress Analysis and Sealing Performance in Bolted Flange Connections With Cover of Pressure Vessel Subjected to Internal Pressure

2004 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Rie Higuchi
Keyword(s):  
Internal Pressure ◽  
Pressure Vessel ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Pressure Application ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Bolted Flange ◽  
Good Agreement ◽  
Spiral Wound

The stresses of a bolted flange connection with a cover of pressure vessel (CPV) in which a spiral wound gasket is inserted, under internal pressure are analyzed taking account a hysteresis of the gasket using the finite element method (FEM). The leakage tests were also conducted for an actual bolted flange connection with a CPV and a spiral wound gasket. Using the calculated contact gasket stress distribution of the bolted flange connection with the CPV under internal pressure and the tightness parameter, the values of the new gasket constants were obtained by taking into account the changes in the contact gasket stress. A difference in the new gasket constants between the estimated values obtained from the actual bolted flange connection with the CPV and the values obtained by the PVRC procedure was small. In addition, a method to determine the bolt preload for a given tightness parameter was demonstrated. The obtained results of the bolt preload for the bolted flange connection with the CPV were in a fairly good agreement with those obtained by the PVRC procedure under a lower pressure application. However, a difference in the bolt preload was about 7% when the internal pressure was increased.

FEM Stress Analysis and Sealing Performance in Bolted Flange Connections With Cover of Pressure Vessel Subjected to Internal Pressure

2003 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Rie Higuchi
Keyword(s):  
Internal Pressure ◽  
Contact Stress ◽  
Pressure Vessel ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Bolted Flange ◽  
Contact Stress Distribution ◽  
Spiral Wound

The stresses of a bolted flange connection with a cover of pressure vessel (CPV) in which a spiral wound gasket is inserted, under internal pressure are analyzed taking account a hysteresis of the gasket by using the finite element method (FEM). The leakage tests were also conducted using an actual bolted flange connection with a CPV with a spiral wound gasket. Using the contact stress distribution of the bolted flange connection with a CPV under internal pressure and the tightness parameter, the values of the new gasket constants were obtained by taking into account the changes in the contact stress. A difference in the new gasket constants between the estimated values obtained from the actual bolted flange connection with a CPV and the values obtained by the PVRC procedure was small. In addition, a method to determine the bolt preload for a given tightness parameter was demonstrated. The obtained results of the bolt preload for the bolted flange connection with a CPV were in a fairly good agreement with those obtained by the PVRC procedure under a lower pressure application. However, a difference in the bolt preload was about 7% when the internal pressure was increased.

Axi-Symmetric Stress Analysis and Determination of Bolt Preload in Bolted Flange Connections With Cover of Pressure Vessel Subjected to Internal Pressure

2005 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Satoshi Nagata ◽  
Yosuke Akita
Keyword(s):  
Internal Pressure ◽  
Pressure Vessel ◽  
Theory Of Elasticity ◽  
Body Contact ◽  
Flange Connection ◽  
Bolt Preload ◽  
Three Body ◽  
Bolted Flange ◽  
The Given ◽  
Spiral Wound

The stresses of a bolted flange connection with a cover of pressure vessel (CPV) in which a spiral wound gasket is inserted, under internal pressure are analyzed taking account a hysteresis of the gasket using the axi-symmetrical theory of elasticity as a three-body contact problem. In addition, for the verification of the analyses, finite-element calculations were also done. The Leakage tests were conducted for an actual bolted flange connection with a CPV and a spiral wound gasket. Using the calculated contact gasket stress distribution of the bolted flange connection with the CPV under internal pressure and the tightness parameter, the values of the new gasket constants were obtained by taking into account the changes in the contact gasket stress. A difference in the new gasket constants between the estimated values obtained from the actual bolted flange connection with the CPV and the values obtained by the PVRC procedure was small. In addition, a method to determine the bolt preload for a given tightness parameter was demonstrated. The obtained results of the bolt preload for the bolted flange connection with the CPV were in a fairly good agreement with those obtained by the PVRC procedure under a lower pressure application. However, a difference in the bolt preload was about 7% when the given tightness parameter was increased.

Stress Analysis and Sealing Performance Evaluation in Rectangular Box-Shape Bolted Flange Connection With Gasket Subjected to Internal Pressure

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Toshiyuki Sawa ◽  
Ryo Kurosawa ◽  
Wataru Maezaki
Keyword(s):  
Finite Element Method ◽  
Internal Pressure ◽  
Research Council ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
The Difference ◽  
Bolted Flange

The contact gasket stress distributions in a rectangular box-shape bolted flange connection with a compressed sheet gasket subjected to internal pressure were analyzed using the finite element method. Leakage tests were also conducted for an actual rectangular box-shape bolted flange connection with a compressed sheet gasket under internal pressure. Using the obtained 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 from the Pressure Vessel Research Council (PVRC) procedure was substantial. In addition, a method to determine the bolt preload for a given tightness parameter was demonstrated and the difference in the determined bolt preload was shown between the present study and the PVRC procedure. The characteristics of the rectangular box-shape bolted flange connection were demonstrated by comparing those of circular bolted flange connections.

Effects of Scatter in Bolt Preload on the Sealing Performance in Bolted Flange Connections With Cover of Pressure Vessel Under Internal Pressure

2006 ◽  
Author(s):  
Satoshi Nagata ◽  
Toshiyuki Sawa ◽  
Seiichi Hamamoto
Keyword(s):  
Internal Pressure ◽  
Pressure Vessel ◽  
Torque Control ◽  
Control Methods ◽  
Stress Distributions ◽  
Flange Connection ◽  
Gas Leakage ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Bolted Flange

It has been well known that the scatter in axial bolt forces of bolted flange connections tightened by torque control methods is substantial. In evaluating the sealing performance of a bolted flange connection with a gasket subjected to internal pressure, it is necessary to know the contact gasket stress distributions due to the scatter of the axial bolt forces in the flange connections tightened by torque control methods. This paper deals with the leakage of a bolted flange connection with a cover of pressure vessel including a spiral wound gasket tightened by a torque wrench. The scatter in the axial bolt forces was measured using strain gauges attached at the shank of bolts. The amount of leakage from the bolted flange connection with cover of pressure vessel was measured by so-called pressure decay method. The gas employed was Helium. From the measured leakage, the actual assembly efficiency is examined. The eight bolts and nuts were tightened according to the ASME PCC-1 method and Japanese method developed by High Pressure Institute (HPI). The difference in the bolt preload was shown between the ASME method and the HPI method. The contact gasket stress distributions at the interface of the flange connection with the gasket were calculated under the measured axial bolt forces by means of finite element analysis. Using the calculated gasket contact stress distribution, the amount of gas leakage was estimated. The estimated gas leakage was compared with the measured results.

Stress Analysis and Determination of Bolt Preload in Pipe Flange Connections With Gaskets Under Internal Pressure

2002 ◽  
Vol 124 (4) ◽  
pp. 385-396 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Naofumi Ogata ◽  
Takahito Nishida
Keyword(s):  
Internal Pressure ◽  
Contact Stress ◽  
Theory Of Elasticity ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Bolt Preload ◽  
Contact Stress Distribution ◽  
Good Agreement ◽  
Spiral Wound

The stresses of a pipe flange connection with a spiral-wound gasket under internal pressure are analyzed taking account a nonlinearity and a hysteresis of the gasket by using an axisymmetric theory of elasticity and the finite element method (FEM). The leakage tests were also conducted using an actual pipe flange connection with a spiral-wound gasket. Using the contact stress distribution of the pipe flange connection with 3-in. nominal diameter under internal pressure and the tightness parameter, the values of the new gasket constants are obtained by taking into account the changes in the contact stress. A difference in the new gasket constants between the estimated values obtained from the actual pipe flange connection and the values obtained by the PVRC procedure is small. In addition, a method to determine the bolt preload for a given tightness parameter is demonstrated. The obtained results of the bolt preload for the pipe flange connection are in a fairly good agreement with those obtained by the PVRC procedure under a lower pressure application. However, a difference in the bolt preload is about 10% when an internal pressure is increased.

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

2007 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Ryo Kurosawa ◽  
Yasuaki Tatsumi
Keyword(s):  
Internal Pressure ◽  
Fem Analysis ◽  
Bolted Joints ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Analysis And Evaluation ◽  
Flange Connection ◽  
Sealing Performance ◽  
Helium Gas ◽  
Bolted Flange

Bolted joints with gaskets such as non-circular flange connections have been widely used in mechanical structures, nuclear and chemical industry, and so on. They are usually used under internal pressure as well as other loadings such as thermal, impact loadings and so on. In designing the non-circular flange connections with gaskets, it is important to evaluate the sealing performance of the non-circular flange connections with gaskets subjected to internal pressure. An important issue is how to evaluate the sealing performance in the box-shape bolted flange connections by using the contact gasket stress distributions at the interfaces, how to reduce a number of bolt and nuts, that is, how to enlarge the bolt pitch, and how to determine the initial clamping bolt force (preload) by using the new gasket constants. In this paper, the stresses of box-shape flange connection with gaskets subjected to an internal pressure are analyzed using the finite element method (FEM), taking account a hysteresis in the stress-strain curves of the gasket. The contact gasket stress distributions when the internal pressure is applied to the connection are analyzed. The leakage tests were conducted using an actual box-shape flange connection with a gasket Using the contact gasket stress distributions at the interfaces under an internal pressure (Helium gas was used) and the amount of the leakage measured in the experiment, the sealing performances are evaluated experimentally and theoretically by changing the bolt pitch in the connections. Discussion is made on the effect of the bolt pitch on the sealing performance in the above connections.

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.

The Effect of Clamping Force and Material Properties on the Tightness Performance a Flexible Box-Shaped Flange Bolted Joint

2008 ◽  
Author(s):  
Ryou Kurosawa ◽  
Toshiyuki Sawa ◽  
Satoshi Nagata ◽  
Yasuaki Tatsumi
Keyword(s):  
Internal Pressure ◽  
Bolted Joints ◽  
Clamping Force ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Sealing Performance ◽  
Helium Gas ◽  
Bolted Flange ◽  
Cover Material

Bolted joints with gaskets such as non-circular flange connections have been widely used in mechanical structures, nuclear and chemical industry, and so on. They are usually used under internal pressure as well as other loadings such as thermal, impact loadings and so on. In designing the non-circular flange connections with gaskets, it is important to evaluate the sealing performance of the non-circular flange connections with gaskets subjected to internal pressure. An important issue is how to evaluate the sealing performance in the box-shaped bolted flange connections by using the contact gasket stress distributions at the interfaces, how to reduce the weight and how to determine the initial clamping bolt force (preload) by using the new gasket constants. In this paper, the stresses of box-shaped flange connection with gaskets subjected to an internal pressure are analyzed using the finite element method (FEM), taking account a hysteresis in the stress-strain curves of the gasket. The reduced contact gasket stress distributions are analyzed when the internal pressure is applied to the connection. The leakage tests were conducted using an actual box-shaped flange connection with a gasket. Using the reduced contact gasket stress distributions at the interfaces under an internal pressure (Helium gas was used) and the amount of the leakage measured in the experiment, the sealing performances are evaluated experimentally and theoretically by changing the initial clamping force and cover material in the connections. In addition, the sealing performance of the connection with raised face is also examined. Discussion is made on the effects of the initial clamping force, cover material and the types of facing on the sealing performance in the above connections.

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

2009 ◽  
Author(s):  
Kentaro Tenma ◽  
Ryou Kurosawa ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Automobile Industry ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Analysis And Evaluation ◽  
Flange Connection ◽  
Sealing Performance ◽  
Helium Gas ◽  
Bolted Flange ◽  
Bolt Diameter

Bolted joints inserting gaskets such as box-shape flange connections have been widely used in mechanical structures, nuclear and chemical industry, and so on. In automobile industry, box-shape connections are applied in oil-pan structure. They are usually used under internal pressure as well as other loadings such as thermal, impact loadings and so on. In designing the box-shape flange connections with gaskets, it is important to evaluate the sealing performance of connections under internal pressure. An important issue is how to evaluate the sealing performance in the connections by using the contact gasket stress distributions at the interfaces and how to determine the initial clamping bolt force (preload) for preventing leakage. In this paper, the stresses of box-shape flange connection with gaskets subjected to an internal pressure are analyzed using the finite element method (FEM), taking into account a hysteresis in the stress-strain curves of the gasket. The contact gasket stress distributions of the connections under the internal pressure are analyzed. The leakage tests were conducted using an actual box-shape flange connection with a gasket. Using the contact gasket stress distributions at the interfaces under an internal pressure (Helium gas was used) and the amount of the leakage measured in the experiment, the sealing performances are evaluated experimentally and numerically. Furthermore, the effect of the nominal bolt diameter, the bolt pitch and flange cover seating types (raised face / flat face) is examined on the sealing performances of box-shape flange connections. Discussion is made on the sealing performance in the above connections.

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