Bolt preload scatter and relaxation behaviour during tightening a 4 in-900# flange joint with spiral wound gasket

2008 ◽  
Vol 222 (2) ◽  
pp. 123-134 ◽  
Author(s):  
M. Abid ◽  
S. Hussain
Keyword(s):  
Relaxation Behaviour ◽  
Flange Joint ◽  
Bolt Preload ◽  
Spiral Wound

Stress Analysis and the Sealing Performance Evaluation of Pipe Flange Connection With Spiral Wound Gaskets Under Internal Pressure

2002 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Naofumi Ogata
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Contact Stress ◽  
Strain Curve ◽  
Stress Distributions ◽  
Element Analysis ◽  
Flange Connection ◽  
Nominal Diameter ◽  
Bolt Preload ◽  
Spiral Wound

This paper deals with the stress analysis of a pipe flange connection with a spiral wound gasket using the elasto-plastic finite element method taking account the hysteresis and the non-linearity in the stress-strain curve of the spiral wound gasket, when an intemal pressure is applied to the pipe flange connections with the different nominal diameters from 2″ to 20″. The effects of the nominal diameter of the pipe flange on the contact stress distributions at the interfaces are examined. Leakage tests of the pipe flange connections with 3″ and 20″ nominal diameters were conducted and measurement of the axial bolt force was also performed. The results by the finite element analysis are fairly consistent with the experimental results concerning the variation in the axial bolt force. By using the contact stress distributions and the results of the leakage test, the new gasket constants are evaluated. As a result, it is found that the variations in the contact stress distributions are substantial due to the flange rotation in the pipe flange connections with the larger nominal diameter. In addition, a method to determine the bolt preload for a given tightness parameter is 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.

Elasto-Plastic FEM Stress Analysis of Pipe Flange Connections Under Internal Pressure

2006 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Satoshi Nagata ◽  
Naofumi Ogata
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Contact Stress ◽  
Strain Curve ◽  
Stress Distributions ◽  
Element Analysis ◽  
Nominal Diameter ◽  
Bolt Preload ◽  
Spiral Wound

This paper deals with the stress analysis of a pipe flange connection with a spiral wound gasket using the elasto-plastic finite element method taking account the hysteresis and the non-linearity in the stress-strain curve of the spiral wound gasket, when an internal pressure is applied to the pipe flange connections with the different nominal diameters from 2 to 20. The effects of the nominal diameter of the pipe flange on the contact stress distributions at the interfaces are examined. Leakage tests of the pipe flange connections with 3 and 20 nominal diameters were conducted and measurement of the axial bolt force was also performed. The results by the finite element analysis are fairly consistent with the experimental results concerning the variation in the axial bolt force. By using the contact stress distributions and the results of the leakage test, the new gasket constants are evaluated. As a result, it is found that the variations in the contact stress distributions are substantial due to the flange rotation in the pipe flange connections with the larger nominal diameter. In addition, a method to determine the bolt preload for a given tightness parameter is demonstrated.

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.

Assembly of Gasketed Bolted Flange Joints Using Torque Control of Preload Method: FEA Approach

2013 ◽  
Author(s):  
Muhammad Abid ◽  
Yasir Mehmood Khan ◽  
David H. Nash
Keyword(s):  
Control Method ◽  
Nonlinear Finite Element ◽  
Torque Control ◽  
Flange Joint ◽  
Element Analysis ◽  
Stress Variation ◽  
Elastic Interactions ◽  
Bolt Preload ◽  
Torque Values ◽  
Bolted Flange

This paper presents the results of the assembly of a gasketed bolted flange joint employing the torque control of preload method using nonlinear finite element analysis. It has been observed that bolt preload scatter due to elastic interactions, flange stress variation, bolt bending due to flange rotation and gasket contact stress variation are very difficult to eliminate when using the torque control method. The behaviour of a gasketed joint using two different target torque values is discussed in detail.

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.

FEM Stress Analysis and Sealing Performance Evaluation in Pipe Flange Connections With Spiral Wound Gaskets Subjected to External Bending Moments: Case Where Internal Fluid is Liquid

2008 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Takeshi Iwamoto ◽  
Kensuke Funada ◽  
Yuya Omiya
Keyword(s):  
Internal Pressure ◽  
Liquid Water ◽  
Strain Curve ◽  
Bending Moments ◽  
Stress Distributions ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Nominal Pressure ◽  
Reliable Design ◽  
Spiral Wound

The leakage evaluation when gas is used is more severe than that when liquid is used in pipe flange connections. In a practical design, it is also necessary to examine the leakage in the connections under liquid internal pressure application. The contact gasket stress distribution in the connection with a spiral wound gasket subjected to internal pressure and bending moments were analyzed using elasto-plastic (EP) finite element method (FEM) taking account hysteresis and nonlinearity in the stress-strain curve of the gasket. The effects of initial clamping bolt force (bolt preload), the nominal pressure and the nominal diameter of pipe flange and the equivalent pressure when the leakage occurs on the contact gasket stress distributions were examined. The leakage tests for the connections under the bending moments and the internal pressure were also conducted by using liquid (water). By using the results of the leakage tests and the calculated contact gasket stress distributions, the sealing performance of the connections was evaluated. It was found that the sealing performance of the connection can be estimated when liquid (water) was used, that is, when the contact gasket stress becomes zero, the leakage occurs. In addition, a method for determining the bolt preload in the connections under the bending moments was proposed for the reliable design.

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

2016 ◽  
Vol 230 (6) ◽  
pp. 464-473 ◽  
Author(s):  
N Rino Nelson ◽  
N Siva Prasad ◽  
AS Sekhar
Keyword(s):  
Elevated Temperature ◽  
Internal Pressure ◽  
Contact Stress ◽  
Thermal Loading ◽  
Elevated Temperatures ◽  
Flange Joint ◽  
Temperature Dependent ◽  
Surface Rotation ◽  
Bolt Preload ◽  
Seating Surface

Gasketed flange joints are usually subjected to internal pressure at high temperature. The most important requirement of flange joint is to provide leak-free joint under operating condition. In the present study, temperature-dependent nonlinear gasket properties of spiral-wound gasket at elevated temperatures are obtained experimentally and included in the analysis. The relaxation of gasket contact stress in both single and twin-gasketed joints at elevated temperatures is compared. It is observed that the ability to withstand internal pressure decreases with increase in temperature in both single and twin-gasketed flange joints. But, the twin-gasketed flange joint is found to withstand higher internal pressure than single-gasketed joint at a given bolt preload and temperature. The influence of gasket seating surface rotation on the distribution of gasket radial contact stress at elevated temperature is studied. The effect of elevated temperature on flange stresses of twin-gasketed joint is also examined.

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