scholarly journals An Ability to Adapt and Change

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.

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.


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):  
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


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):  
Louis E. Hayden ◽  
J. Robert Sims

The need for more efficient and cost effective design of ship board equipment has never been greater. Pressure vessels on board ships can account for significant volume and weight and thus affect the overall performance of the vessel. Classically ship board pressure vessels have been designed to ASME Section VIII, Division 1. This code requires pressure vessels that are designed using a basic design by rule approach with a 3.5 to 1 design margin on specified minimum tensile strength. In recent years the ASME Standards Committee that is responsible for Section VIII has developed two design codes, Section VIII, Division 2 Alternative Rules for Construction of Pressure Vessels and Section VIII, Division 3 Alternative Rules for Construction of High Pressure Vessels. These pressure vessel design codes offer lower design margins, an improved design by rule approach for Division 2 and allow or require design by analysis based on the vessel operating conditions and environment such as cyclic service. Use of these codes can improve ship board vessel design by lowering the weight of vessels while providing a safe reliable pressure vessel. Paper published with permission.


Author(s):  
Richard C. Biel ◽  
Gregory Cano

Adoption of composite reinforced pressure vessels (CRPV) into the ASME Boiler and Pressure Vessel Code represented advancement in the technology of pressure vessels. The advantage of this construction technique is that the weight of a CRPV for compressed gas service built may be reduced to about one-half conventional pressure vessel of the same capacity. The concept of hoop wrapping fibers in a plastic composite (>90% fiber fill) makes full utilization of the fiber strength as the fibers share the hoop load with a metal cylinder. With reduced hoop stresses in the metal, a substantial reduction in wall thickness is attainable. The process of adoption of this technology presented several challenges and some robust administrative hurdles. These included coordination with ASME BPV Code Section X for the composite application and Section VIII for the steel design and overall acceptance of the Case. The most vexing technical challenge was the inspection of an unfinished weld on the inside of the shell from the outside of the shell. The next challenge was to gain consensus on the testing criteria for the acceptance of finished vessels. Case 2390 was drafted in the winter of 2000 and spring of 2001 and approved for publication after nine revisions with an approval date of October 9, 2002. The Case was subsequently adopted into the body of ASME BPV Code Section VIII, Division 3 [1] (VIII-3) in the 2010 edition.


1980 ◽  
Vol 102 (1) ◽  
pp. 98-106 ◽  
Author(s):  
G. J. Mraz ◽  
E. G. Nisbett

Steels at present included in Sections III and VIII of the ASME Boiler and Pressure Vessel Code severely limit its application for high-pressure design. An extension of the well-known AISI 4300 series low alloy steels has long been known as “Gun Steel.” These alloys, which are generally superior to AISI 4340, offer good harden-ability and toughness and have been widely used under proprietary names for pressure vessel application. The ASTM Specification A-723 was developed to cover these nickel-chromium-molybdenum alloys for pressure vessel use, and is being adopted by Section II of the ASME Boiler and Pressure Vessel Code for use in Section VIII, Division 2, and in Section III in Part NF for component supports. The rationale of the specification is discussed, and examples of the mechanical properties obtained from forgings manufactured to the specification are given. These include the results of both room and elevated temperature tension tests and Charpy V notch impact tests. New areas of applicability of the Code to forged vessels for high-pressure service using these materials are discussed. Problems of safety in operation of monobloc vessels are mentioned. Procedures for in-service inspection and determination of inspection intervals based on fracture mechanics are suggested.


Author(s):  
Allen Selz ◽  
Daniel R. Sharp

Developed at the request of the US Department of Transportation, Section XII-Transport Tanks, of the ASME Boiler and Pressure Vessel Code addresses rules for the construction and continued service of pressure vessels for the transportation of dangerous goods by road, air, rail, or water. The standard is intended to replace most of the vessel design rules and be referenced in the federal hazardous material regulations, Title 49 of the Code of Federal Regulations (CFR). While the majority of the current rules focus on over-the-road transport, there are rules for portable tanks which can be used in marine applications for the transport of liquefied gases, and for ton tanks used for rail and barge shipping of chlorine and other compressed gases. Rules for non-cryogenic portable tanks are currently provided in Section VIII, Division 2, but will be moved into Section XII. These portable tank requirements should also replace the existing references to the outmoded 1989 edition of ASME Section VIII, Division 1 cited in Title 46 of the CFR. Paper published with permission.


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