The Sealing Performance Evaluation of Bolted Flexible Box-Shaped Flange Joints Under Thermal Conduction Conditions

2009 ◽  
Author(s):  
Ryou Kurosawa ◽  
Toshiyuki Sawa ◽  
Yuya Omiya ◽  
Kentaro Tenma
Keyword(s):  
Elevated Temperature ◽  
Internal Pressure ◽  
Thermal Conduction ◽  
Stress Distributions ◽  
Flange Joint ◽  
The Finite Element Method ◽  
Gas Leakage ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Helium Gas

Bolted joints with gaskets such as flexible box-shaped flange joints have been used in mechanical structures. The joints are usually used under internal pressure as well as other loadings such as thermal, impact loadings and so on. In designing the bolted flexible box-shaped flange joint with gaskets, it is important to evaluate the sealing performance of the joints under internal pressure and thermal conduction conditions. In this paper, the contact gasket stress distributions and changes in bolt load in the bolted flexible box-shaped flange joint with joint sheet gaskets subjected to internal pressure and thermal conduction condition are analyzed using the finite element method (FEM). The leakage tests were conducted using an actual box-shaped flange connection with a joint sheet gasket. Using the contact gasket stress distributions under internal pressure at an elevated temperature (Helium gas) obtained from the FEM calculations and the amount of the gas leakage measured in the experiment, the sealing performances are evaluated experimentally and numerically. In addition, the effect of the thermal conduction condition on the sealing performance is examined. Furthermore, a method how to determine the bolt preload of the flexible box-shaped flange joint at an elevated temperature for a given tightness parameter is demonstrated. Discussion is made on the sealing performance.

Sealing Performance Evaluation of Box-Shaped Flange Connections Under Thermal Conduction Conditions and Internal Pressure

2010 ◽  
Author(s):  
Kentaro Tenma ◽  
Ryou Kurosawa ◽  
Toshiyuki Sawa
Keyword(s):  
Elevated Temperature ◽  
Internal Pressure ◽  
Thermal Conduction ◽  
Linear Thermal Expansion ◽  
Stress Distributions ◽  
Flange Connection ◽  
Gas Leakage ◽  
Thermal Expansion Coefficients ◽  
Bolt Preload ◽  
Sealing Performance

Bolted connections with gaskets such as flexible box-shaped flange connections have been used in mechanical structures. The connections are usually used under internal pressure as well as other loadings such as thermal, impact loadings and so on. In designing the bolted flexible box-shaped flange connections with gaskets, it is important to evaluate the sealing performance of the connections under internal pressure and thermal conduction conditions. In this paper, the contact gasket stress distributions and changes in bolt preload in the bolted flexible box-shaped flange connection with compressed sheet gaskets subjected to internal pressure and thermal conduction condition are analyzed using the finite element method (FEM). The leakage tests were conducted using an actual box-shaped flange connection with a compressed sheet gasket. Using the contact gasket stress distributions under internal pressure at an elevated temperature (Helium gas) obtained from the FEM calculations and an amount of the gas leakage measured in the experiment, the sealing performances are evaluated experimentally and numerically. The estimated amount of gas leakage is in a fairly good agreement with the measured results. In addition, the effect of the thermal conduction condition on the sealing performance is examined. Furthermore, the effects of the bolt pitch and the linear thermal expansion coefficients of the flanges and the gasket are examined at elevated temperature (20,80,100°C). Discussion is made on the effects of some factors on the sealing performance.

Effects of Scatter in Bolt Preload of Pipe Flange Connections With Spiral Wound Gaskets Under Internal Pressure: In Case of Larger Pipe Flange Connection With 20" Nominal Diameter

2004 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Wataru Maezaki
Keyword(s):  
Internal Pressure ◽  
Contact Stress ◽  
Control Method ◽  
Torque Control ◽  
Stress Distributions ◽  
Gas Leakage ◽  
Nominal Diameter ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Helium Gas

It has been well known that a scatter in axial bolt forces of pipe flange connections tightened by the torque control method is substantial. In practice, pipe flange connections with the larger nominal diameter tightened by the torque control method have been used, frequently. So, in an optimum design of pipe flange connections with gaskets, it is necessary to understand the characteristics of the pipe flange connections with larger nominal diameter under internal pressure and the contact gasket stress distributions due to the scatter of the axial bolt forces in the connections tightened by the torque control method. In this paper, the leakage tests were performed in the actual larger pipe flange connections with 20” nominal diameter using helium gas. Then, 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 calculated contact stress distributions and the results of the leakage tests, the sealing performance was evaluated.

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.

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 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 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.

Thermal Stress Analysis and the Sealing Performance Evaluation of Bolted Flange Connection at Elevated Temperature

2009 ◽  
Author(s):  
Yuya Omiya ◽  
Toshiyuki Sawa
Keyword(s):  
Heat Conduction ◽  
Thermal Stress ◽  
Elevated Temperature ◽  
Internal Pressure ◽  
Theory Of Elasticity ◽  
Gas Leakage ◽  
Sealing Performance ◽  
Helium Gas ◽  
Reliable Design ◽  
Bolted Flange

In designing bolted flange connections under heat conduction conditions and internal pressure, the characteristics such as the contact gasket stress are important factors from reliable design standpoint. They must be examined analytically and experimentally. In this paper, in order to examine the above characteristics, thermal stress of bolted flange connections subjected to internal pressure and heat conduction conditions is analyzed using the theory of elasticity and FEM calculations. The effects of gasket properties and nominal diameter of flanges on the above characteristics are examined numerically. In the experiments, the amount of helium gas leakage in the connection was measured. Using the obtained gasket stress at elevated temperature, a method for estimating the amount of gas leakage is proposed. The analytical results of the above characteristics are compared with the experimental results, with reasonable agreements. The results reveal that the sealing performance increases due to the gasket properties as the temperature increases in this study.

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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document