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.

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

2009 ◽  
Author(s):  
Charles Becht ◽  
Charles Becht
Keyword(s):  
Fatigue Analysis ◽  
Design Rules ◽  
Creep Properties ◽  
Simplified Approach ◽  
Fatigue Design ◽  
Allowable Stresses ◽  
Section Viii ◽  
Cyclic Service ◽  
Creep Regime

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, Div 2 [1] 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 construction of vessels using these materials at temperatures above 370°C (700°F). This paper provides a simplified approach for exemption of low chrome alloys that are slightly into the creep range from fatigue analysis.

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.

Method B Fatigue Screening in ASME BPV Code, Section VIII, Division 2, Part 5

2019 ◽  
Author(s):  
Kenneth Kirkpatrick ◽  
Christopher R. Johnson ◽  
J. Adin Mann
Keyword(s):  
Fatigue Damage ◽  
Pressure Vessel ◽  
Fatigue Analysis ◽  
Damage Factor ◽  
Simple Method ◽  
Mechanical Loads ◽  
Penalty Factor ◽  
Section Viii ◽  
Cyclic Service ◽  
Division 2

Abstract ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 2, Part 5 Method B fatigue screening is intended to be a quick and simple method that is sufficiently conservative to screen components in cyclic service thus not requiring detailed fatigue analysis. The method assesses pressure, thermal, and mechanical loads separately. The basis for each portion of the method is discussed along with an alternative bases for the assessments. Each assessment is reformulated as a fatigue damage factor and all variables are provided so that the intent of each equation is clearly identifiable. A penalty factor will be included in each equation rather than assuming one penalty for all designs, the reformulation creates penalty for non-fatigue resistant designs and reduces the penalty for fatigue resistant designs. Examples are given showing the potentially non-conservative results if a summed damage is not used.

Fatigue Design for Non-Welded Regions According to New European and American Pressure Vessel Standards

2009 ◽  
Author(s):  
Franz Rauscher
Keyword(s):  
Pressure Vessel ◽  
Extreme Values ◽  
Experimental Results ◽  
Correction Factors ◽  
Specific Design ◽  
Fatigue Design ◽  
Special Cases ◽  
Section Viii ◽  
Division 2

EN 13445-3 [1], which was first published in the year 2002, includes separate fatigue design checks for unwelded and welded regions. Furthermore, the new 2007 ASME Boiler & Pressure Vessel Code Section VIII Division 2 [2] includes separated design checks for welded and unwelded regions. Because of differences in the procedures, the approaches of these standards are not directly comparable. Therefore, comparable design curves for special cases and/or for extreme values of parameters are evaluated. Differences in the procedures are discussed and examples are given for special cases. For the unwelded regions, which are covered by this paper, the following approach was chosen: Design curves from EN 13445-3 are corrected by the extreme values of the necessary correction factors. These corrected EN 13445-3 fatigue design curves are compared to the design curves given in ASME VIII-2. As examples of typical usage, some experimental results are compared to the specific design curves.

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.

Elastic Allowable Stress Basis for Elevated Temperature Design in the Creep Regime

2016 ◽  
Author(s):  
Chithranjan Nadarajah ◽  
Benjamin F. Hantz ◽  
Sujay Krishnamurthy
Keyword(s):  
Finite Element ◽  
Elevated Temperature ◽  
Pressure Vessel ◽  
Reasonable Agreement ◽  
Allowable Stress ◽  
Elastic Stresses ◽  
Finite Element Stress Analysis ◽  
Section Viii ◽  
Elevated Temperature Design ◽  
Creep Regime

ASME Section VIII, Division II, Boiler and Pressure Vessel Code does not have any design by analysis procedures for designing pressure vessel components in the creep regime. This publication presents a methodology for evaluating and categorizing elastic stresses calculated from finite element stress analysis when designing in the creep regime. The proposed methodology is compared with multi axial creep results for various pressure vessel components and found to be in reasonable agreement.

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.

scholarly journals An Ability to Adapt and Change

2014 ◽  
Vol 136 (11) ◽  
pp. 36-37
Author(s):  
Madiha El Mehelmy Kotb
Keyword(s):  
Life Cycle ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Electronic Format ◽  
The World ◽  
Regulatory Approach ◽  
Section Viii ◽  
Division 2 ◽  
Service Inspection ◽  
Technical Services

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.

User’s Design Specification Preparation for 2¼Cr-1Mo-¼V Reactors in Accordance With ASME Section VIII, Division 2 Code and Code Case 2605

2013 ◽  
Author(s):  
Radoslav Stefanovic ◽  
Alicia Avery ◽  
Kanhaiya Bardia ◽  
Reza Kabganian ◽  
Vasile Oprea ◽  
...  
Keyword(s):  
Operating Temperature ◽  
Design Specification ◽  
Element Analysis ◽  
Analysis And Evaluation ◽  
Reheat Cracking ◽  
Inelastic Analysis ◽  
Allowable Stresses ◽  
Section Viii ◽  
Fatigue Evaluation ◽  
Division 2

Today’s hydroprocessing reactor manufacturers use 2¼Cr–1Mo–¼V steel to build lighter reactors than conventional Cr-Mo reactors. Manufacturing even lighter hydroprocessing reactors has been enabled with the introduction of the new ASME Section VIII Division 2 Code, initially released in 2007. The higher allowable stresses in the new Division 2 for these Vanadium-modified steels permits even lighter reactors to be built while maintaining suitable design margins. The new Division 2 Code requires additional engineering to ensure safe design. One of the challenges the engineer is faced with, is preparation of the User’s Design Specification (UDS) including new and more stringent requirements for fatigue evaluation. As the operating temperature of the rector is higher than 371°C, engineers have to evaluate the fatigue life of the reactor in accordance with Code Case 2605 (CC2605). CC2605 requires inelastic analysis and evaluation effects of creep. Vanadium-modified reactors require additional care during fabrication to prevent higher hardness around weld areas, reheat cracking, and reduced toughness at lower temperatures in the “as welded” condition. This paper provide guidance for the preparation of an ASME Section VIII Division 2 User’s Design Specification including process descriptions of all the cycles expected for the life of the rector and analysis requested by CC2605. An example of such an analysis, including finite element analysis results, is provided in this paper. Requirements to provide the material specification is also discussed with an emphasis on prevention of reheat cracking, hardenability, and temper and hydrogen embitterment.

Overview of Revisions to the ASME Boiler and Pressure Vessel Code Section VIII Division 3 for the 2017 Edition and Near Future

2017 ◽  
Author(s):  
Daniel Peters ◽  
Gregory Mital ◽  
Adam P. Maslowski
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Central Area ◽  
Local Strain ◽  
Pressure Vessels ◽  
Conformity Assessment ◽  
Inspection Planning ◽  
Section Viii ◽  
American Society ◽  
Rules Changes

This paper provides an overview of the significant revisions pending for the upcoming 2017 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section VIII Division 3, Alternative Rules for Construction of High Pressure Vessels, as well as potential changes to future editions under consideration of the Subgroup on High Pressure Vessels (SG-HPV). Changes to the 2017 edition include the removal of material information used in the construction of composite reinforced pressure vessels (CRPV); this information has been consolidated to the newly-developed Appendix 10 of ASME BPVC Section X, Fiber-Reinforced Plastic Pressure Vessels. Similarly, the development of the ASME CA-1, Conformity Assessment Requirements standard necessitated removal of associated conformity assessment information from Section VIII Division 3. Additionally, requirements for the assembly of pressure vessels at a location other than that listed on the Certificate of Authorization have been clarified with the definitions of “field” and “intermediate” sites. Furthermore, certain design related issues have been addressed and incorporated into the current edition, including changes to the fracture mechanics rules, changes to wires stress limits in wire-wound vessels, and clarification on bolting and end closure requirements. Finally, the removal of Appendix B, Suggested Practice Regarding Post-Construction Requalification for High Pressure Vessels, will be discussed, including a short discussion of the new appendix incorporated into the updated edition of ASME PCC-3, Inspection Planning Using Risk Based Methods. Additionally, this paper discusses some areas in Section VIII Division 3 under consideration for improvement. One such area involves consolidation of material models presented in the book into a central area for easier reference. Another is the clarification of local strain limit analysis and the intended number and types of evaluations needed for the non-linear finite element analyses. The requirements for test locations in prolongations on forgings are also being examined as well as other material that can be used in testing for vessel construction. Finally, a discussion is presented on an ongoing debate regarding “occasional loads” and “abnormal loads”, their current evaluation, and proposed changes to design margins regarding these loads.

Sign in / Sign up

Export Citation Format

Share Document