Increased Allowable Stresses for Earthquake and Wind Loads in Section VIII, Division 1

1986 ◽  
Vol 108 (4) ◽  
pp. 518-520
Author(s):  
A. Selz
Keyword(s):  
Pressure Vessel ◽  
Wind Loads ◽  
Membrane Stress ◽  
Allowable Stresses ◽  
Division 1 ◽  
Section Viii ◽  
The Subject ◽  
Short Time ◽  
Creep Regime ◽  
Division 2

There has been a need for some time to provide rules for allowable stresses for short-time and infrequent loading such as earthquake and wind loads in Section VIII, Division 1 of the Boiler and Pressure Vessel Code. Such rules exist in Section VIII, Division 2, in Section III, and in many other Codes. Division 1 has been silent on the subject. This has caused some manufacturers to make their own rules, and some to overdesign their hardware. Neither situation is without problems. Therefore, in 1979 the Boiler and Pressure Vessel Committee undertook to develop rules for Section VIII, Division 1. This work resulted in the addition of paragraph UG-23(d) to the Code, in the Summer, 1983 Addenda. The paragraph permits an increase in general primary membrane stress of 20 percent for earthquake and wind loads for temperatures below the creep regime.

Extension of Fatigue Exemption Rules in Section VIII, Division 2 Slightly Into the Creep Regime

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Charles Becht ◽  
Charles Becht
Keyword(s):  
Pressure Vessel ◽  
Creep Properties ◽  
Simplified Approach ◽  
Fatigue Design ◽  
Allowable Stresses ◽  
Section Viii ◽  
Cyclic Service ◽  
American Society ◽  
Creep Regime ◽  
Division 2

A number of alloys have applications slightly into the creep range that are in cyclic service, such as process reactors. The 2007 edition of Section VIII, Division 2 (2007, ASME Boiler and Pressure Vessel Code, Section VIII, Division 2, The American Society of Mechanical Engineers) provides allowable stresses for these materials, which may be controlled by creep properties. However, the fatigue design rules and fatigue exemption rules are not applicable, precluding the construction of vessels using these materials at temperatures above 370∘C (700∘F). This paper provides a simplified approach for the exemption of low chrome alloys that are slightly into the creep range from fatigue analysis. Part 1 of this paper (Becht, C., 2009, “Elevated Temperature Shakedown Concepts,” ASME J. Pressure Vessel Technol. 133, p. 051203) describes shakedown concepts, which are the basis for the criteria evaluated in this paper.

A Study of the Conservatism in ASME BPVC Section VIII Division 2 Opening Design for External Pressure

2019 ◽  
Author(s):  
Barry Millet ◽  
Kaveh Ebrahimi ◽  
James Lu ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
External Pressure ◽  
The Other ◽  
Finite Element Analyses ◽  
Division 1 ◽  
Section Viii ◽  
Allowable Compressive Stress ◽  
Division 2

Abstract In the ASME Boiler and Pressure Vessel Code, nozzle reinforcement rules for nozzles attached to shells under external pressure differ from the rules for internal pressure. ASME BPVC Section I, Section VIII Division 1 and Section VIII Division 2 (Pre-2007 Edition) reinforcement rules for external pressure are less stringent than those for internal pressure. The reinforcement rules for external pressure published since the 2007 Edition of ASME BPVC Section VIII Division 2 are more stringent than those for internal pressure. The previous rule only required reinforcement for external pressure to be one-half of the reinforcement required for internal pressure. In the current BPVC Code the required reinforcement is inversely proportional to the allowable compressive stress for the shell under external pressure. Therefore as the allowable drops, the required reinforcement increases. Understandably, the rules for external pressure differ in these two Divisions, but the amount of required reinforcement can be significantly larger. This paper will examine the possible conservatism in the current Division 2 rules as compared to the other Divisions of the BPVC Code and the EN 13445-3. The paper will review the background of each method and provide finite element analyses of several selected nozzles and geometries.

Heat Treatment of Fabricated Components and the Effect on Properties of Materials

2019 ◽  
Author(s):  
Shyam Gopalakrishnan ◽  
Ameya Mathkar
Keyword(s):  
Heat Treatment ◽  
Pressure Vessel ◽  
Test Specimen ◽  
Stress Relieving ◽  
Division 1 ◽  
Asme Code ◽  
Alloy Steels ◽  
Section Viii ◽  
Properties Of Materials ◽  
Division 2

Abstract Most of the heavy thickness boiler and pressure vessel components require heat treatment — in the form of post weld heat treatment (PWHT) and sometimes coupled with local PWHT. It is also a common practice to apply post heating/ intermediate stress relieving/ dehydrogenation heat treatment in case of alloy steels. The heat treatment applied during the various manufacturing stages of boiler and pressure vessel have varying effects on the type of material that is used in fabrication. It is essential to understand the effect of time and temperature on the properties (like tensile and yield strength/ impact/ hardness, etc.) of the materials that are used for fabrication. Considering the temperature gradients involved during the welding operation a thorough understanding of the time-temperature effect is essential. Heat treatments are generally done at varying time and temperatures depending on the governing thickness and the type of materials. The structural effects on the materials or the properties of the materials tends to vary based on the heat treatment. All boiler and pressure vessel Code require that the properties of the material should be intact and meet the minimum Code specification requirements after all the heat treatment operations are completed. ASME Code(s) like Sec I, Section VIII Division 1 and Division 2 and API recommended practices like API 934 calls for simulation heat treatment of test specimen of the material used in fabrication to ascertain whether the intended material used in construction meets the required properties after all heat treatment operations are completed. The work reported in this paper — “Heat treatment of fabricated components and the effect on properties of materials” is an attempt to review the heat treatment and the effect on the properties of materials that are commonly used in construction of boiler and pressure vessel. For this study, simulation heat treatment for PWHT of test specimen for CS/ LAS plate and forging material was carried out as specified in ASME Section VIII Div 1, Div 2 and API 934-C. The results of heat treatment on material properties are plotted and compared. In conclusion recommendations are made which purchaser/ manufacturer may consider for simulation heat treatment of test specimen.

Review of Section VIII, Division 1 and 2 Changes, 2008–2010

2010 ◽  
Author(s):  
Thomas P. Pastor
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Major Event ◽  
The Past ◽  
Division 1 ◽  
Section Viii ◽  
Division 2

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.

Analytical and Numerical Evaluation of the Cyclic Yield Area Criteria for Shakedown Requirements

2002 ◽  
Author(s):  
Isoharu Nishiguchi ◽  
Asao Okamoto ◽  
Norimichi Yamashita ◽  
Mitsuru Aoki
Keyword(s):  
Pressure Vessel ◽  
Numerical Evaluation ◽  
Failure Modes ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Stress Evaluation ◽  
Division 1 ◽  
Section Viii ◽  
Division 2 ◽  
Stress Criteria

The rules in codes such as the ASME Boiler and Pressure Vessel Code Section III Division 1 and Section VIII Division 2, provide the concept of stress categorization to prevent inelastic failure modes based on the elastic analyses. The categorization of the stresses obtained by the FEM analysis, however, is not always clear and the Three Dimensional FEM Stress Evaluation in JPVRC (TDF committee) has been developed alternative criteria to dispense with the stress categorization. As for the evaluation of the primary plus secondary stress, criteria based on the concept of the Cyclic Yield Area (CYA) have been developed. In this paper, the recent results obtained in the committee are summarized to evaluate the validity and the usability of the criteria.

A New Technique for Approximating the Stress in Pad-Type Nozzles Attached to a Spherical Shell

1987 ◽  
Vol 109 (2) ◽  
pp. 188-192 ◽  
Author(s):  
T. Oikawa ◽  
T. Oka
Keyword(s):  
Design Of Experiments ◽  
Spherical Shell ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Approximate Analysis ◽  
Membrane Stress ◽  
Division 1 ◽  
Section Viii ◽  
A New Technique ◽  
Future Work

The generally applicable approximate analysis for pad-type nozzles was shown statistically to be reliable through the use of the design of experiments. The focus was on membrane stresses due to an internal pressure in discontinuous portions of the pad-type nozzle attached to a spherical shell designed in the ASME Boiler and Pressure Vessel (BPV) Code, Section VIII, Division 1. Although Division 1 does not require stress evaluations in discontinuous portions, the results given in this paper show that the maximum membrane stress can be above the yield stress for some generally used materials. This evidence will be reviewed in future work.

Recent Advances in the ASME Section VIII Division 1 and 2 Pressure Vessel Codes

1981 ◽  
Vol 103 (1) ◽  
pp. 119-124
Author(s):  
G. G. Karcher ◽  
R. A. Ecoff
Keyword(s):  
Pressure Vessel ◽  
Mechanical Engineering ◽  
Pressure Vessels ◽  
Basic Design ◽  
Recent Advances ◽  
Division 1 ◽  
Section Viii ◽  
The Subject

Numerous revisions, updates and advances have been incorporated in the ASME Section VIII Code on “Pressure Vessels.” All of them have been published in “Mechanical Engineering” as required by ANSI accredited organization procedures and a few have also been the subject of specific technical papers. The objectives of this paper is not the duplication of these already published works but rather a highlighting of the more significant or, in some cases, subtle revisions that have been incorporated in Section VIII since the 1974 edition. By way of introduction, the basic design philosophies of Division 1 and 2 are also outlined.

ASME B&PV Code Section VIII Pressure Vessel Design: A Comparison — Division 1 Versus Division 2

2002 ◽  
Author(s):  
Dwight V. Smith
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Main Design ◽  
Division 1 ◽  
Asme Code ◽  
Section Viii ◽  
Design Requirements ◽  
Division 2

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.

An Overview of the New ASME Section VIII, Division 2 Pressure Vessel Code

2003 ◽  
Author(s):  
David A. Osage
Keyword(s):  
Pressure Vessel ◽  
Major Revision ◽  
Division 1 ◽  
Efficient Construction ◽  
Section Viii ◽  
Division 2

ASME has decided to undertake a major revision, including significant technical updates, of Section VIII, Division 2 of the Boiler and Pressure Vessel Code. Division 1 will not be affected, but it is anticipated that the revised Division 2 Code will allow significantly more efficient construction for many current Division 1 applications. As a result, it is expected that the revised code will be used for many more applications than the current Division 2.

Design, Manufacture and Safety Aspects of Forged Vessels for High-Pressure Services

1980 ◽  
Vol 102 (1) ◽  
pp. 98-106 ◽  
Author(s):  
G. J. Mraz ◽  
E. G. Nisbett
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Low Alloy Steels ◽  
Nickel Chromium ◽  
Molybdenum Alloys ◽  
Tension Tests ◽  
Alloy Steels ◽  
Section Viii ◽  
Division 2

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.

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