Experimental Study on the Characteristics of Bolted Pipe Flange Connection Under Bending Moment and Internal Pressure

2020 ◽  
Author(s):  
Xing Zheng ◽  
Toshiyuki Sawa ◽  
Mei Feng ◽  
Honggui Ding
Keyword(s):  
Experimental Study ◽  
Internal Pressure ◽  
Bending Moment ◽  
Wind Load ◽  
Force Distribution ◽  
Flange Connection ◽  
Special Cases ◽  
Minimum Residual ◽  
Spiral Wound

Abstract After a bolted gasketed pipe flange connection is assembled, the pipe flange connection is usually subjected to some additional loads such as bending moment, own weight, wind load and so on. These additional loads will lead to changing the axial bolt force distribution of the pipe flange connection and the distribution will become more and more scattered. As a result, the minimum residual axial bolt force will be much smaller and the minimum contact gasket stress will decrease, so a leakage is easy to occur in the connection. In special cases such as earthquakes, the bolted pipe flange connection is usually subjected to a high bending moment. Then sometimes leakage accidents occur. In order to promote the safety of the connections and to avoid them being broken under the earthquakes, in the present paper, the equivalent pressure and the assembly efficiency in the pipe flange connection of class 150 4″ are measured experimentally. The leak rates of the connection using spiral-wound gasket when a bending moment was applied or not applied were measured to elicit the equivalent pressure. Moreover, some tightening procedures such as JIS B 2251, ASME PCC-1 Legacy and GB/T 38343 were applied to tighten the pipe flange connection. The axial bolt force distribution, the assembly efficiency based on the target axial bolt force and the assembly efficiency based on tightness parameter of the connection when bending moment was applied or not applied were measured, and the results are compared. As a result, the equivalent pressure under a given bending moment is obtained, and a difference of the equivalent pressure between our results and Kellogg’s results is demonstrated. In addition, the new assembly efficiency based on the tightness parameter is also measured under a given bending moment as well as internal pressure. Using the equivalent pressure and the assembly efficiency obtained in the present paper, a new design will be possible for pipe flange connections under bending moment.

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.

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.

Effect of External Bending Moment on the Sealing Performance of Pipe Flange Connection

2010 ◽  
Author(s):  
Yoshio Takagi ◽  
Hiroyasu Torii ◽  
Toshiyuki Sawa ◽  
Yuya Omiya
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Deformation Characteristic ◽  
Bending Moment ◽  
Displacement Curve ◽  
Linear Deformation ◽  
Flange Connection ◽  
Sealing Performance ◽  
Non Linear ◽  
The Difference

Since an external bending moment affects the sealing performance of pipe flange connection, it is important to investigate this effect. This paper analyzed the contact gasket stress distribution of pipe flange connections and evaluates the effect of external bending moment on the sealing performance from the viewpoint of changes in contact gasket stress. The study includes the FE analyses and the experimental leakage tests. The FE analyses suggested the large decrease of contact gasket stress at tension side and small increase at compression side. The difference in change in contact gasket stress was caused by the non-linear hysteresis characteristics of stress-displacement curve of gasket. The FE analyses also suggested that the loading order, internal pressure and external bending moment, also affected the sealing performance due to the non-linear deformation characteristic of the gasket. The sealing performance when the external bending moment applied prior to the internal pressure was degraded more than when the internal pressure was applied prior to the external bending moment. The experimental leakage tests using helium (He) gas were analyzed by the finite element method and discussed. This paper also evaluated the stress distribution in the pipe flange under external bending moment. The results suggested that the hub stress dominated the flange structure and the most important factor in designing the flange.

552 The evaluations of bolted flange connection with spiral wound gasket under internal pressure

2015 ◽  
Vol 2015 (0) ◽  
pp. 152-153
Author(s):  
Akira Muramatsu ◽  
Khan Maksud Uddin ◽  
Kazuya Kurihara ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Flange Connection ◽  
Bolted Flange ◽  
Spiral Wound

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.

Relaxation of the Bolted Flange Connection

2020 ◽  
Author(s):  
Robert Taylor
Keyword(s):  
Internal Pressure ◽  
Temperature Cycling ◽  
Bolted Connection ◽  
Relaxation Properties ◽  
Flange Connection ◽  
Bolt Stress ◽  
Bolted Flange ◽  
Spiral Wound

Abstract This study researches the total relaxation of a bolted flange connection, taking into account, the relaxation of various bolt grades in conjunction with different semi-metallic gaskets. The test temperatures are: 300 °F (149 °C), 500 °F (260 °C), 650 °F (343 °C) and 800 °F (427 °C), where each temperature setting will cycle three times to obtain the relaxation value for each cycle. The three types of bolt materials for evaluation include ASTM A193 B7, ASTM A193 B16 and ASTM B8M CL2 along with gaskets styles of spiral wound gasket with inner ring, spiral wound gasket with NO inner ring and the kammprofile gasket (grooved metal gasket with covering layers), all in accordance to ASME B16.20 – 2017. The above variations and conditions will be tested at two different initial bolt stresses of 35,000 psi (241 MPa) and 65,000 psi (448 MPa) with a constant internal pressure of 150 psi (10.3 Bar). The results will show relaxation values for the different bolt and gasket types versus the various temperature cycling conditions indicated above. Focusing on: does a certain gasket style offer lower relaxation properties through less creep and/or higher recovery? Does a certain bolt grade offer better stress retention? Is there variation in initial bolt stress for the different style of gasket? How does the initial bolt stress affect the relaxation properties of the bolted connection?

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 Pipe Flange Connections With Gaskets Subjected to Internal Pressure and External Bending Moment

2002 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Mitsuhiro Matsumoto
Keyword(s):  
Internal Pressure ◽  
Strain Curve ◽  
Bending Moment ◽  
Stress Distributions ◽  
Stress Strain Curve ◽  
Flange Connection ◽  
Leakage Test ◽  
Sealing Performance ◽  
Calculated Average ◽  
Good Agreement

This paper deals with the characteristics of a pipe flange connection with a compressed asbestos sheet gasket (JIS) subjected to an internal pressure and a bending moment. The contact gasket stress distributions at the interfaces between pipe flanges and a gasket are calculated by the elasto-plastic finite element method taking account a hysteresis and a non-linearity in the stress-strain curve of the compressed asbestos sheet gasket. In addition, measurements of a change in axial bolt force and leakage test were conducted using an actual pipe flange connection with the gasket subjected to the internal pressure and the bending moment. The new gasket constants are calculated by using the results of the leakage test and the calculated average contact gasket stress. The values of the new gasket constants obtained by the present study are in a fairly good agreement with those from ROTT (PVRC). It is found that the value of the tightness parameter is increased as the bending moment is increased. This is because the average contact gasket stress under the bending moment is increased, while it is decreased under the internal pressure.

Sign in / Sign up

Export Citation Format

Share Document