Technical Basis and Strategy for Consolidation of ASME Boiler and Pressure Vessel Code, Section III, Subsection NC (Class 2) and Subsection ND (Class 3) Into a Single Subsection

Author(s):  
Jie Wen ◽  
Robert Keating ◽  
Timothy M. Adams

Abstract ASME Boiler Pressure Vessel Code, Section III, Division 1, Subsection NC, Class 2 components, and Subsection ND, Class 3 components, have significant technical and administrative similarities. The ASME BPV III Standards Committee has a long-standing goal of combining these two subsections (NC and ND). Consolidating Subsections NC and ND will simplify, reduce repetitions and make the Code easier to use. Additionally, a combined Subsection NC/ND will simplify Code maintenance. To facilitate this consolidation, the Subgroup on Component Design, under the BPV III Standards Committee assigned a Task Group to develop a strategy to combine the two subsections into a single subsection while maintaining both Class 2 and Class 3 as separate classes of construction. Both Subsections NC and ND of the Code have been completely reviewed, compared and the technical bases for the differences have been established. The conclusion of this review is that there are only a few major technical differences between the two code class rules; however, there are a significant number of editorial differences. Based on the review, the Task Group developed a strategy that completes the consolidation within two publishing cycles of Code edition. For the Code Edition 2019, two separate Subsections NC and ND books will be published to resolve editorial differences and otherwise align the two subsections. For the Code Edition 2021, a single merged subsection will be published. This paper provides the background for the proposed code change, discusses the detailed result of the NC/ND comparison, and provides the basis for the major technical differences. The paper will also update the status of the project and code actions needed to consolidate to a single subsection.

Author(s):  
Suzanne McKillop ◽  
Jie Wen ◽  
Robert Keating ◽  
Timothy M. Adams

In 1974, the Level D Service Limits for Section III, Division 1, Class 1 components were published in Non-Mandatory Appendix F titled “Rules for Evaluation of Service Loading with Level D Service Limits”. Over the past 40 years, the scope of the Appendix F has been expanded to be applicable to certain Class 1, Class 2 and Class 3 components and supports in Division 1 as well as in Division 3 and Division 5. With each addition, the organization and implementation of the rules in Appendix F became more cumbersome for the user and consistency between the Appendix and the Code Books1 was not maintained. At the same time, the use of these rules has evolved to the point where the non-Mandatory Appendix is essential the default for Level D Service Limits. Starting in the 2017 Code edition, the component design rules will reference Mandatory Appendix XXVII when Design by Analysis is used to determine Level D Service Limits. In particular, the component design rules, or rules specific to design of components and not Design by Analysis, were removed from Appendix XXVII and placed in the appropriate Code Book. This approach resulted in noteworthy updates to the support rules in Subsection NF, the core support rules in Subsection NG, the valve rules in NB-3500, and the piping rules in NB/NC/ND-3600. The detailed approach used to incorporate the component design rules into each Code Book are presented in this paper.


Author(s):  
Jie Wen ◽  
Suzanne McKillop ◽  
Timothy M. Adams ◽  
Robert Keating

In 1974, the Level D Service Limits for Section III, Division 1, Class 1 components were published in Non-Mandatory Appendix F titled “Rules for Evaluation of Service Loading with Level D Service Limits”. Over the past 40 years, the scope of Appendix F has been expanded to be applicable to certain Class 1, Class 2 and Class 3 components and supports in Division 1 as well as in Division 3 and Division 5. With each addition, the organization and implementation of the rules in Appendix F became more cumbersome for the user and consistency between the Appendix and the Code Books1 was not maintained. At the same time, the use of these rules has evolved to the point where the non-Mandatory Appendix is essential the default for Level D Service Limits. Starting in the 2017 Code edition, the component design rules will reference Mandatory Appendix XXVII when Design by Analysis is used to determine Level D Service Limits. This paper describes the methodology utilized to convert Non-Mandatory Appendix F to Mandatory Appendix XXVII which includes the history of the Level D Rules in the ASME Code, the philosophy taken to convert Non-Mandatory Appendix F to Mandatory Appendix XXVII, and an overview of the new Appendix XXVII. The approaches to ensure identical safety margins are maintained and the basis for adding or clarifying three allowable stress limits are also included.


Author(s):  
Robert O. McGill ◽  
Mark A. Moenssens ◽  
George A. Antaki ◽  
Douglas A. Scarth

This paper presents the technical basis for Code Case N-806, Evaluation of Metal Loss in Class 2 and 3 Metallic Piping Buried in a Back-filled Trench – Section XI, Division 1. This Code Case has been prepared in the ASME Section XI Task Group on Evaluation Procedures for Degraded Buried Pipe. It addresses the nuclear industry need for evaluation procedures and acceptance criteria for the disposition of metal loss that may be discovered during the inspection of piping buried in a back-filled trench. This paper provides background discussion, scope of the Code Case, key definitions and a summary of Code Case methods followed by the basis explanation where necessary. It is organized to follow the same structure as the Code Case for ease of use.


Author(s):  
B. L. Luk ◽  
A. A. Collie ◽  
T. White

Abstract NERO is a series of teleoperated wall climbing vehicles. Each vehicle carries a specific tool for assisting inspection of a nuclear reactor pressure vessel in the U.K. They adopted a simple sliding frame walking mechanism to cope with 250mm head room and 25mm obstacles on the surface. Vacuum suckers are used by the vehicle for climbing vertical surface. The NERO vehicle is driven remotely by an operator via a control console. The status of the vehicle and the control console is displayed on the console’s computer monitor. These vehicles completed their tasks successfully by September 1992.


2018 ◽  
Vol 165 ◽  
pp. 10003
Author(s):  
Ralf Trieglaff ◽  
Jürgen Rudolph ◽  
Martin Beckert ◽  
Daniel Friers

The European Pressure Vessel Standard EN 13445 provides in its part 3 (Design) a simplified method (Clause 17) and a detailed method for fatigue assessment (Clause 18). Clause 18 “Detailed Assessment of Fatigue Life” is under revision within the framework of the European working group CEN/TC 54/WG 53 – Design methods with the aim of reaching a significant increase in user-friendliness and a clear guideline for the application. This paper is focused on the new informative annex NA ”Instructions for structural stress oriented finite elements analyses using brick and shell elements”. As an essential amendment for the practical user, the determination of structural stress ranges for fatigue assessment of welds is further specified in this new annex. Different application methods for the determination of structural stresses are explained in connection with the requirements for finite element models and analyses. This paper will give a short overview of the proposed approaches of structural stress determination in annex NA of the revised EN 13445-3. It will present the status of the approaches based on the results of fatigue analyses according to EN 13445-3 Clause 18 for different application examples. For verification purposes, the results of the approaches proposed in EN 13445-3 are compared with the results of other pressure vessel design codes for nuclear and non-nuclear application.


Author(s):  
Takayasu Tahara

Pressure equipment in refinery and petrochemical industries in Japan has been getting old, mostly more than 30 years in operation. Currently, the Japanese regulations for pressure equipment in service are the same as those in existence during the fabrication of the pressure equipment. Accordingly, there is an immediate need for an up to date more advanced “Fitness For Service” (FFS) evaluation requirements for pressure equipment. In order to introduce the latest FFS methodologies to Japanese industries, the High Pressure Institute of Japan (HPI) has organized two task groups. One is a working group for development of a maintenance standard for non-nuclear industries. Its prescribed code “Assessment procedure for crack-like flaws in pressure equipment” is for conducting quantitative safety evaluations of flaws detected in common pressure equipment such as pressure vessels, piping, storage tanks. The other is a special task group to study of API RP579 from its drafting stage as a member of TG579. The FFS Handbook, especially for refinery and petrochemical industries, has been developed based on API RP579 with several modifications to meet Japanese pressure vessel regulations on April 2001. [1] It is expected that both the Standard and FFS handbook will be used as an exemplified standard with Japanese regulations for practical maintenance. This paper presents concepts of “Assessment procedure for crack-like flaws in pressure equipment” HPIS Z101, 2001 [2].


Author(s):  
Robert O. McGill ◽  
Mark A. Moenssens ◽  
George A. Antaki ◽  
Douglas A. Scarth

ASME Section XI Code Case N-806, for evaluation of metal loss in Class 2 and 3 metallic piping buried in a back-filled trench, was first published in 2012. This Code Case has been prepared by the ASME Section XI Task Group on Evaluation Procedures for Degraded Buried Pipe. The Code Case addresses the nuclear industry need for evaluation procedures and acceptance criteria for the disposition of metal loss that is discovered during the inspection of metallic piping buried in a back-filled trench. A number of additional improvements have been proposed for Code Case N-806. These include expanded guidance for the determination and validation of a corrosion rate and other clarifications to improve ease of use. This paper presents an update of details of the proposed revisions to Code Case N-806 and their technical basis.


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.


Author(s):  
Jan Keltjens ◽  
Philip Cornelissen ◽  
Peter Koerner ◽  
Waldemar Hiller ◽  
Rolf Wink

The ASME Section VIII Division 3 Pressure Vessel Design Code adopted in its 2004 edition a significant change of the design margin against plastic collapse. There are several reasons and justifications for this code change, in particular the comparison with design margins used for high pressure equipment in Europe. Also, the ASME Pressure Vessel Code books themselves are not always consistent with respect to design margin. This paper discusses not only the background material for the code change, but also gives some practical information on when pressure vessels could be designed to a thinner wall.


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