scholarly journals Finite Element Analysis of Gasket in Pressure Vessel

Author(s):  
Sanjana Jaishankara

Abstract: Pressure vessel is a closed container designed to hold liquids or gases at a pressure which are higher than the surrounding atmospheric pressure. These pressure vessels are not made as a single component but manufacture with an assembly of many other components and connected through bolted joints or riveted joints or welded joints. These joints are susceptible to failure and cause leakage of the liquid or gas which are very dangerous and sometimes causes heavy loss of life, health and property. Hence proper care has to be taken during the design analysis processes by following ASME section VIII division 1 which specifies the design-by-formula approach while division 2 contains a set of alternative rules based on design by Analysis (FEA) to determine the expected deformation and stresses that may develop during operation. The ASME section-VIII division-2 standards are used for the design of pressure vessel. Leakage in gasketed flanged joints have always been a great problem for the process industry. The sealing performance of a gasketed flanged joints depends on its installation and applied loading conditions. The present project work involves the design procedure and stress analysis (Structural Analysis) for the leak proof pressure vessel at the gasket under three different gasket conditions. Keywords: 1. FEM, 2. ASME, 3. ANSYS, 4. Gasket,5. Displacement,6. Stress

2014 ◽  
Vol 136 (11) ◽  
pp. 36-37
Author(s):  
Madiha El Mehelmy Kotb

This article reviews about the views of Madiha El Mehelmy Hotb, the Head of the Pressure Vessels Technical Services Division for Regie Du Batiment Du Quedec, on how ASME Boiler and Pressure Vessel Code has evolved over the years. Hotb reveals that during the 1980s, ASME’s regulatory approach covered all aspects of the life cycle of a boiler or a pressure vessel from design to being taken out of service. It also confirmed every step in between – fabrication, installation, repair and modification, and in-service inspection. During later years, the institution moved toward accreditation of authorized inspection agencies, changed the publication cycle from three years to two, eliminated addenda, and restructured the Code committees. New Section VIII and division 2 were written, and the Codes were published in digital electronic format. Hotb believes that the Code will continue to be widely used and adopted in future. It will have a bigger and larger input from all over the world and will have further outreach and adoption by far more countries.


2014 ◽  
Vol 598 ◽  
pp. 194-197
Author(s):  
Hong Jun Li ◽  
Qiang Ding ◽  
Xun Huang

Stress linearization is used to define constant and linear through-thickness FEA (Finite Element Analysis) stress distributions that are used in place of membrane and membrane plus bending stress distributions in pressure vessel Design by Analysis. In this paper, stress linearization procedures are reviewed with reference to the ASME Boiler & Pressure Vessel Code Section VIII Division 2 and EN13445. The basis of the linearization procedure is stated and a new method of stress linearization considering selected stress tensors for linearization is proposed.


Author(s):  
Thomas P. Pastor

Three years ago the major event within Section VIII was the publication of the new Section VIII, Division 2. The development of the new VIII-2 standard dominated Section VIII activity for many years, and a new standard has been well received within the industry. As expected with any new standard, some of the material that was intended to be published in the standard was not ready at the time of publication so numerous revisions have taken place in the last two addenda. This paper will attempt to summarize the major revisions that have taken place in VIII-2 and VIII-1, including a detailed overview of the new Part UIG “Requirements for Pressure Vessels Constructed of Impregnated Graphite”. I have stated in the past that the ASME Boiler and Pressure Vessel Code is a “living and breathing document”, and considering that over 320 revisions were made to VIII-1 and VIII-2 in the past three years, I think I can safely say that the standard is alive and well.


Author(s):  
Sebastian Schindler

The paper discusses the advantages and disadvantages of the two well known Design by Analysis methods for unfired pressure vessels: the stress categorisation method (as given e.g. in the 2004 ASME B&BV Code Section VIII Division 2 [1], and EN 13445-3 Annex C [2]) and the new Direct Route (using elastic-plastic finite-element analysis) as given in EN 13445-3 Annex B [2]. A comparison of results is given for examples of various degree of difficulty to show the principal ideas and the applicability of the two approaches: a dished end with a nozzle in the knuckle region, a cylindrical shell to flat end connection and a rather complex header of an air cooler with rectangular cross section. As shown by the considered examples, the Direct Route method gives unique solutions (which is not always the case for stress categorisation) and can be advantageous in some cases, but requires a more time consuming analysis. The questionable design limits given by the 3f-criterion of the stress categorisation method can be avoided by usage of the progressive plastic deformation design check of the Direct Route if the required number of action cycles is low.


Author(s):  
Michael W. Guillot ◽  
Jack E. Helms

Finite element analysis is widely used to model the stresses resulting from penetrations in pressure vessels to accommodate components such as nozzles and man-ways. In many cases a reinforcing pad is required around the nozzle or other component to meet the design requirements of Section VIII, Division 1 or 2, of the ASME Pressure Vessel Code [1]. Several different finite element techniques are currently used for calculating the effects of reinforcing pads on the shell stresses resulting from penetrations for nozzles or man-ways. In this research the stresses near a typical reinforced nozzle on a pressure vessel shell are studied. Finite element analysis is used to model the stresses in the reinforcing pad and shell. The commercially available software package ANSYS is used for the modeling. Loadings on the nozzle are due to combinations of internal pressure and moments to simulate piping attachments. The finite element results are compared to an analysis per Welding Research Council Bulletin 107 [2].


2014 ◽  
Vol 601 ◽  
pp. 84-87 ◽  
Author(s):  
Serban Vasilescu ◽  
Costin Ilinca

The stresses and deflections developed due to all piping loads produce some significant deformation in the nozzles of the pressure vessels. In this paper a spherical pressure vessel with two cylindrical nozzles are analyzed. The stresses in the nozzles are evaluated using two comparative methods: one of them represents the classical way of using the superposition of the axial, bending and torsional loads; the other one is based on the requirements of the ASME Boiler and Pressure Vessel Cod, Section VIII, Division 2 and is developed by a FE analysis. In order to obtain the loads (forces and moments) at the end of the nozzle a specialized finite element program has been used. This program (Coade Caesar 5.30) allows studying the strength and flexibility behavior of the pipes that connect the analyzed nozzle with the rest of the plant. The results obtained are compared in order to find when the using of the classical methods of strength of materials can be used as conservative approaches. The finite element method is applied in order to check the most important load cases that appear during the interaction between pipes and shell. In this respect the sustained (proper gravity loads), expansion (thermal loads) and occasional (wind and seismic loads) are combined in order to check all the requirements of ASME. This study contains also the effect of the pressure trust and the influence of the real geometry of the junction (nozzle-shell) in the peaks of the stresses.


Author(s):  
Gurinder Singh Brar ◽  
Yogeshwar Hari ◽  
Dennis K. Williams

This paper presents the comparison of a reliability technique that employs a Fourier series representation of random asymmetric imperfections in a cylindrical pressure vessel subjected to external pressure. Comparison with evaluations prescribed by the ASME Boiler and Pressure Vessel Code, Section VIII, Division 2 Rules for the same shell geometries are also conducted. The ultimate goal of the reliability type technique is to predict the critical buckling load associated with the chosen cylindrical pressure vessel. Initial geometric imperfections are shown to have a significant effect on the load carrying capacity of the example cylindrical pressure vessel. Fourier decomposition is employed to interpret imperfections as structural features that can be easily related to various other types of defined imperfections. The initial functional description of the imperfections consists of an axisymmetric portion and a deviant portion, which are availed in the form of a double Fourier series. Fifty simulated shells generated by the Monte Carlo technique are employed in the final prediction of the critical buckling load. The representation of initial geometrical imperfections in the cylindrical pressure vessel requires the determination of appropriate Fourier coefficients. Multi-mode analyses are expanded to evaluate a large number of potential buckling modes for both predefined geometries and associated asymmetric imperfections as a function of position within a given cylindrical shell. The probability of the ultimate buckling stress that may exceed a predefined threshold stress is also calculated. The method and results described herein are in stark contrast to the “knockdown factor” approach as applied to compressive stress evaluations currently utilized in industry. Recommendations for further study of imperfect cylindrical pressure vessels are also outlined in an effort to improve on the current design rules regarding column buckling of large diameter pressure vessels designed in accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division 2 and ASME STS-1.


2007 ◽  
Vol 129 (4) ◽  
pp. 754-758
Author(s):  
T. P. Pastor ◽  
D. A. Osage

The technology for pressure equipment design continues to advance each and every day. The ASME Boiler and Pressure Vessel Code has been keeping pace with these advances over the last 92 years. As far back as the 1960s, it was recognized that the special requirements for design of pressure vessels operating at pressures over 2000 psi (13.7 MPa) called for special rules, and ASME issued Sec. VIII, Division 2 of Alternative Rules for Pressure Vessels. Since that time, the understanding of failure mechanisms and advances in material science, nondestructive testing, and computer-aided design has progressed to the stage where a new approach was needed not only in the content of design codes but in the way they are presented and organized. This paper introduces the newly issued ASME Sec. VIII, Division 2 of 2007 edition and explores the technical concepts included and the new format designed for ease of use. Included are results of test exercises sponsored by ASME giving actual applications of the new Code for design of vessels. This paper demonstrates ASME’s commitment to provide manufacturers and users of pressure equipment with the most up-to-date technology in easy to use standards that service the international market.


Author(s):  
Dwight V. Smith

Historically, the ASME B&PV Code, Section VIII, Division 2, Alternative Rules for Construction of Pressure Vessels (Div.2), ASME [1], was usually considered applicable only for large, thick walled pressure vessels. Otherwise, ASME B&PV Code, Section VIII, Division 1, Rules for Construction of Pressure Vessels (Div. 1), ASME [2], was typically applied. A case can also be made for the application of the Div. 2 Code Section for some vessels of lesser thicknesses. Each vessel should be closely evaluated to ensure the appropriate choice of Code Section to apply. This paper discusses some of the differences between the Div. 1 and Div. 2 Code Sections, summarizes some of the main design requirements of Div. 2, and presents a ease for considering its use for design conditions not usually considered by some, to be appropriate for the application of Div. 2 of the ASME Code.


Author(s):  
Zhenning Cao ◽  
Les Bildy ◽  
David A. Osage ◽  
J. C. Sowinski

The theory behind the pressure-area method that is incorporated in the ASME B&PV Code, Section VIII-2 is presented in this paper. Background and insight to the nozzle rules of ASME B&PV Code, Section VIII, Division 2, Part 4, paragraph 4.5 are also provided. Recommendations for modifying the current nozzles rules, those published in ASME B&PV Code, Section VIII, Division 2, 2010 Edition, is given based on continuing research and development efforts. A comparison between experimental results, results derived from detailed finite element analysis (FEA), the rules prior to the VIII-2 Rewrite (2004 Edition), and the rules in VIII-2 are provided in terms of a design margin and permissible maximum allowable working pressure (MAWP) computed with the design rules. A complete description of the theory including a commentary and comparison to experimental results is provided in WRC529 [1].


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