Analytical Modeling of a Bolted Flange Joint Subjected to Creep Relaxation

2004 ◽  
Author(s):  
Akli Nechache ◽  
Abdel-Hakim Bouzid ◽  
Van Ngan Leˆ
Keyword(s):  
Experimental Data ◽  
Analytical Modeling ◽  
Nuclear Reactors ◽  
Weak Link ◽  
Flange Joint ◽  
Load Relaxation ◽  
Controlling Parameter ◽  
Asme Code ◽  
Subsequent Loss ◽  
Bolted Flange

Bolted flanged gasketed joints are the weak link between pressure vessel equipments including nuclear reactors. Their leakage tightness behavior is compromised due to the effect of creep of the gasket, the bolts and the flange, which relaxes the bolt load and causes a subsequent loss of the gasket contact stress. This is especially true when the joint is operating under high pressure and high temperature conditions. Apart from an acknowledgement of this affect, the ASME code does not give specific guidelines to help the design engineer in assessing this effect. The objective of this paper is to present an analytical method capable of predicting the bolt load relaxation in a gasketed joint as a result of creep of either the gasket, the bolt and the flange separately or all together. The proposed method is validated by comparison with 3D FE models of different size flanges and experimental data. A strong emphasis will be put on flange rigidity, which is the major controlling parameter of the load relaxation.

Flange Joint Bolt Spacing Requirements

2007 ◽  
Author(s):  
William J. Koves
Keyword(s):  
Complex System ◽  
Analytical Solution ◽  
Code Design ◽  
Flange Joint ◽  
Stress Variation ◽  
Design Rules ◽  
Asme Code ◽  
Leak Tightness ◽  
Bolted Flange ◽  
Bolt Spacing

The bolted flange joint assembly is a complex system. System stresses are dependent on elastic and nonlinear interaction between the bolting, flange and gasket. The ASME Code design rules provides a method for sizing the flange and bolts to be structurally adequate for the specified pressure design conditions and are based on an axi-symmetric analysis of a flange. The ASME rules do not address the circumferential variation in gasket and flange stress due to the discrete bolt loads. Proper bolt spacing is important to maintain leak tightness between bolts and to avoid distorting the flange. This paper provides an analytical solution for the gasket and flange stress variation between bolts. The analytical solution is validated with 3-D Finite Element solutions of standard flange designs.

Analytical Modeling of Bolted Flange Joints With Full Face Gaskets

2004 ◽  
Author(s):  
Hichem Galai ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Contact Stress ◽  
Analytical Modeling ◽  
Elastic Interaction ◽  
Bolted Joints ◽  
Low Leakage ◽  
Proposed Model ◽  
Asme Code ◽  
The Many ◽  
Full Face ◽  
Bolted Flange

Following the low leakage performance of flat face flanges, neither Appendix 2 nor Appendix Y of the ASME code which describes the design rules of flanges, are reliable to assess load changes when full face gaskets are used. The prediction of the tightness of these connections relies very much on the level of precision of the gasket contact stress during operation. However, determining this stress is complex, due to the many geometric and material parameters involved. This paper analyses the behaviour of bolted joints with full face gaskets. It presents an analytical approach to evaluate the operating flange rotation, gasket load and contact stress that may be used for leak prediction. The method is based on the gasket-bolt-flange elastic interaction, including flange rotational flexibility. The proposed model is supported by comparison with numerical FEA of different size flanges.

Finite Element Analysis of a Gasketed Flange Joint Under Combined Internal Pressure and Thermal Transient Loading

2007 ◽  
Author(s):  
Muhammad Abid ◽  
Javed A. Chattha ◽  
Kamran A. Khan
Keyword(s):  
Finite Element Analysis ◽  
Steady State ◽  
Internal Pressure ◽  
Thermal Loading ◽  
Flange Joint ◽  
Element Analysis ◽  
Transient Loading ◽  
Thermal Transient ◽  
Transient Thermal ◽  
Bolted Flange

Performance of a bolted flange joint is characterized mainly by its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. In the available published work, thermal behavior of the pipe flange joints is discussed under steady state loading with and without internal pressure and under transient loading condition without internal pressure. The present design codes also do not address the effects of steady state and thermal transient loading on the structural integrity and sealing ability. It is realized that due to the ignorance of any applied transient thermal loading, the optimized performance of the bolted flange joint can not be achieved. In this paper, in order to investigate gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and transient thermal loading, an extensive nonlinear finite element analysis is carried out and its behavior is discussed.

Fully Plastic Failure Stresses and Allowable Crack Sizes for Circumferentially Surface Cracked Pipes Subjected to Tensile Loading

2021 ◽  
Author(s):  
Kunio Hasegawa ◽  
David Dvorak ◽  
Vratislav Mares ◽  
Bohumir Strnadel ◽  
Yinsheng Li
Keyword(s):  
Experimental Data ◽  
Bending Moment ◽  
Limit Load ◽  
Tensile Loading ◽  
Crack Size ◽  
Plastic Failure ◽  
Circumferential Crack ◽  
Asme Code ◽  
American Society ◽  
Better Than

Abstract Fully plastic failure stresses for circumferentially surface cracked pipes subjected to tensile loading can be estimated by means of limit load criteria based on the net-section stress approach. Limit load criteria of the first type (labelled LLC-1) were derived from the balance of uniaxial forces. Limit load criteria of the second type are given in Section XI of the ASME (American Society of Mechanical Engineering) Code, and were derived from the balance of bending moment and axial force. These are labelled LLC-2. Fully plastic failure stresses estimated by using LLC-1 and LLC-2 were compared. The stresses estimated by LLC-1 are always larger than those estimated by LLC-2. From the literature survey of experimental data, failure stresses obtained by both types of LLC were compared with the experimental data. It can be stated that failure stresses calculated by LLC-1 are better than those calculated by LLC-2 for shallow cracks. On the contrary, for deep cracks, LLC-2 predictions of failure stresses are fairly close to the experimental data. Furthermore, allowable circumferential crack sizes obtained by LLC-1 were compared with the sizes given in Section XI of the ASME Code. The allowable crack sizes obtained by LLC-1 are larger than those obtained by LLC-2. It can be stated that the allowable crack size for tensile stress depends on the condition of constraint of the pipe, and the allowable cracks given in Section XI of the ASME Code are conservative.

Application of Bolted Flange Joint Assembly Guidelines HPIS Z103 TR to ePTFE Sheet Gasket

2008 ◽  
Author(s):  
Hirokazu Tsuji ◽  
Yuuki Terui
Keyword(s):  
Relaxation Rate ◽  
Modulus Of Elasticity ◽  
Elastic Interaction ◽  
Flange Joint ◽  
Fiber Sheet ◽  
Force Reduction ◽  
Assembly Procedure ◽  
Bolted Flange ◽  
Application Scope ◽  
Joint Assembly

Bolt tightening guidelines HPIS Z 103 TR for flange joint assemblies have been developed to provide a simple and effective procedure to tighten flange joint bolts. This assembly procedure is applicable to compressed fiber sheet gaskets and spiral wound gaskets, but is not applicable to expanded PTFE (ePTFE) sheet gaskets for the reason that the ePTFE material has lower modulus of elasticity and higher creep/relaxation rate. In this study, expansion of the application scope of HPIS Z103 TR to ePTFE sheet gaskets is investigated. Tightening tests are conducted using flange joint specimens of JPI 4 inch and 6 inch, and all bolt forces and flange gaps are measured at each tightening step to check for uneven tightening. Uniformity of the bolt forces and flange gaps are comparable to those obtained by other types of gaskets or by tightening procedure ASME PCC-1. The influences of gasket relaxation and elastic interaction on the bolt forces are also demonstrated. As a result, flange joint assembly guidelines HPIS Z 103 TR can be considered applicable to the high-density ePTFE sheet gasket, although a post-tightening step of 1 or 2 passes is necessary to compensate for the bolt force reduction induced by gasket relaxation.

Application of Plastic Region Bolt Tightening to Flange Joint Assembly: Behavior of Large Diameter Flange

2009 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Plastic Region ◽  
Load Factor ◽  
Past Study ◽  
Flange Joint ◽  
The Past ◽  
Sealing Performance ◽  
Assembly Behavior ◽  
Bolted Flange

In the past study the plastic region tightening has been applied to the bolted flange joint with smaller nominal diameter and its advantages have been demonstrated, however, behavior of the bolted flange joint with larger diameter is not investigated. Flange rotation of the bolted flange joint with large diameter increases when the internal pressure is applied. Gasket stress is not uniform and it may cause leak accident. So, it is necessary to investigate the behavior of the larger diameter flange. The present paper describes the behavior of bolted flange joint with large diameter under plastic region tightening. Firstly, API 20-inch flange joint tightened to the plastic region by bolt with a smaller diameter and superiority in the uniformity of the axial bolt force is demonstrated. And then the internal pressure is applied to the bolted flange joint and the behavior of the additional axial bolt force is demonstrated. The axial bolt force decreases with increasing the internal pressure, and the load factor is negative due to increasing of the flange rotation. However, the load factor of the bolted flange joint tightened to the plastic region by using the bolt with the smaller diameter approached zero. Using the bolts with smaller diameter is advantageous to the flange joint with the larger diamter, whose load factor is negative, to prevent the leakage. Additionally, the leak rate from the bolted flange joint is measured and the sufficient sealing performance is obtained.

S-CO2 Turbine Design for Decay Heat Removal System of Sodium Cooled Fast Reactor

2016 ◽  
Author(s):  
Seong Kuk Cho ◽  
Jekyoung Lee ◽  
Jeong Ik Lee ◽  
Jae Eun Cha
Keyword(s):  
Experimental Data ◽  
Fast Reactor ◽  
Design Methodology ◽  
Nuclear Reactors ◽  
Heat Removal ◽  
Design Code ◽  
Decay Heat ◽  
Turbine Design ◽  
Heat Removal System ◽  
Removal System

A Sodium-cooled Fast Reactor (SFR) has receiving attention as one of the promising next generation nuclear reactors because it can recycle the spent nuclear fuel produced from the current commercial nuclear reactors and accomplish higher thermal efficiency than the current commercial nuclear reactors. However, after shutdown of the nuclear reactor core, the accumulated fission products of the SFR also decay and release heat via radiation within the reactor. To remove this residual heat, a decay heat removal system (DHRS) with supercritical CO2 (S-CO2) as the working fluid is suggested with a turbocharger system which achieves passive operational capability. However, for designing this system an improved S-CO2 turbine design methodology should be suggested because the existing methodology for designing the S-CO2 Brayton cycle has focused only on the compressor design near the critical point. To develop a S-CO2 turbine design methodology, the non-dimensional number based design and the 1D mean line design method were modified and suggested. The design methodology was implemented into the developed code and the code results were compared with existing turbine experimental data. The data were collected under air and S-CO2 environment. The developed code in this research showed a reasonable agreement with the experimental data. Finally using the design code, the turbocharger design for the suggested DHRS and prediction of the off design performance were carried out. As further works, more effort will be put it to expand the S-CO2 turbine test data for validating the design code and methodology.

Limit Loads of Bolted Flange Connections

2021 ◽  
Author(s):  
Finn Kirkemo ◽  
Przemyslaw Lutkiewicz
Keyword(s):  
Calculation Method ◽  
Production Systems ◽  
Pressure Vessels ◽  
Finite Element Analyses ◽  
Limit Loads ◽  
Face To Face ◽  
Structural Capacity ◽  
Process Piping ◽  
Asme Code ◽  
Bolted Flange

Abstract High-pressure applications such as process piping, pressure vessels, risers, pipelines, and subsea production systems use bolted flange connections. Design of flanged joints may be done by design by rules and design by analysis. This paper presents a design by rules method applicable for flanges designed for face-to-face make-up. Limit loads are used to calculate the structural capacity (resistance) of the flanges, bolts, and metallic seal rings. Designers can use the calculation method to size bolted flange connections and calculate the structural capacity of existing bolted flange connections. Finite element analyses have been performed to verify the analytically based calculation method. The intention is to prepare for an ASME code case based on the calculation method presented in this paper.

Bolted Flange Joint Made of Glass Fibre Reinforced Polymer (GFRP) for Oil and Gas Pipelines

2018 ◽  
Author(s):  
Muhsin Aljuboury ◽  
Md Jahir Rizvi ◽  
Stephen Grove ◽  
Richard Cullen
Keyword(s):  
Glass Fibre ◽  
Oil And Gas ◽  
High Strength ◽  
Flange Joint ◽  
Element Analysis ◽  
Glass Fibre Reinforced Polymer ◽  
Linear Behaviour ◽  
Glass Fibre Reinforced ◽  
Gasket Material ◽  
Bolted Flange

The objective of this work is an experimental and numerical investigation for a bol Richard Cullen ted composite flange connection for composite pipes, which are used in the oil and gas applications, and obtain a joint with high strength and high corrosion resistance. For the experimental part, we have designed and manufactured the required mould, which ensures the quality of the composite materials and controls its surface grade. Based on the ASME Boiler and Pressure Vessel Code, Section X, this GFRP flange has been fabricated using biaxial glass fibre braid and polyester resin in a vacuum infusion process. Numerically, an investigation is carried out using 3D finite element analysis (FEA) of a bolted GFRP flange joint including flange, pipe, gasket and bolts. This model has taken into account the orthotropy of the GFRP material and the non-linear behaviour of the rubber gasket material for both the loading and non-loading conditions. Furthermore, the leakage propagation between the flange and the gasket has also been simulated in this investigation by using the pressure-penetration criteria PPNC in ANSYS. Finally, the flange has been tested under the internal pressure and the agreement between the experimental and numerical results is excellent.

Creep Effect of Attached Structures on Bolted Flanged Joint Relaxation

2005 ◽  
Author(s):  
Akli Nechache ◽  
Abdel-Hakim Bouzid
Keyword(s):  
High Temperature ◽  
Creep Behavior ◽  
Temperature Effects ◽  
Analytical Approach ◽  
Load Relaxation ◽  
Creep Effect ◽  
Bolted Flange

The leakage tightness behavior of bolted flange joints is compromised due to high temperature effects and in particular when creep of the materials of the different components of the bolted flanged joint take place. The relaxation of bolted flanged joints is often estimated from the creep of the gasket and the bolts. The creep behavior of the flange ring and the attached structures such as the shell and the hub is often neglected. Apart from an acknowledgement of relaxation due to creep, the designer has no specific tools to accurately assess this effect on the bolt load relaxation. The objective of this paper is to present an analytical approach capable of predicting the bolt load relaxation due to creep of the attached structures. The proposed approach is validated by comparison with 3D FE models of different size flanges. An emphasis will be put towards the importance of including creep of the attached structures in high temperature flange designs.

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