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

Author(s):  
Kenneth Kirkpatrick ◽  
Christopher R. Johnson ◽  
J. Adin Mann

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.

Author(s):  
Jinhua Shi ◽  
Liwu Wei ◽  
Claude Faidy ◽  
Andrew Wasylyk ◽  
Nawal Prinja

Different pressure vessel and piping design codes and standards have adopted different fatigue analysis methods. In order to make some contribution to current efforts to harmonize international design codes and standards, a review of fatigue analysis methods for a number of selected nuclear and non-nuclear design codes and standards has been carried out. The selected design codes and standards are ASME Boiler and Pressure Vessel Code Section III Subsection NB and Section VIII Division 2, EN 12952, EN 13445, EN 13480, PD 5500, RCC-M, RCC-MRx, JSME, PNAEG and R5. This paper presents the initial review results. The results of the study could be used as part of the on-going work of the Codes and Standards Task Force of the World Nuclear Association (WNA) Cooperation in Reactor Design Evaluation and Licensing (CORDEL) Working Group.


2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Charles Becht ◽  
Charles Becht

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.


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):  
Barry Millet ◽  
Kaveh Ebrahimi ◽  
James Lu ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher

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.


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):  
Martin Muscat ◽  
Kevin Degiorgio ◽  
James Wood

Fatigue cracks in welds often occur at the toe of a weld where stresses are difficult to calculate at the design stage. To circumvent this problem the ASME Boiler and PV code Section VIII Division 2 Part 5 [1] uses the structural stress normal to the expected crack to predict fatigue life using elastic analysis and as welded fatigue curves. The European Unfired Pressure Vessel Code [2] uses a similar approach. The structural stress excludes the notch stress at the weld toe itself. The predicted fatigue life has a strong dependency on the calculated value of structural stress. This emphasizes the importance of having a unique and robust way of extracting the structural stress from elastic finite element results. Different methods are available for the computation of the structural hotspot stress at welded joints. These are based on the extrapolation of surface stresses close to the weld toe, on the linearisation of stresses in the through-thickness direction or on the equilibrium of nodal forces. This paper takes a critical view on the various methods and investigates the effects of the mesh quality on the value of the structural stress. T-shaped welded plates under bending are considered as a means for illustration.


Author(s):  
Daniel T. Peters ◽  
Myles Parr

Abstract The use of high pressure vessels for the purpose of storing gaseous fuels for land based transportation application is becoming common. Fuels such as natural gas and hydrogen are currently being stored at high pressure for use in fueling stations. This paper will investigate the use of various levels of autofrettage in high pressure storage cylinders and its effects on the life of a vessel used for hydrogen storage. Unlike many high-pressure vessels, the life is controlled by fatigue when cycled between a high pressure near the design pressure and a lower pressure due to the emptying of the content of the vessels. There are many misunderstandings regarding the need for cyclic life assessment in storage vessels and the impact that hydrogen has on that life. Some manufacturers are currently producing vessels using ASME Section VIII Division 1 to avoid the requirements for evaluation of cylinders in cyclic service. There are currently rules being considered in all of ASME Section VIII Division 1 and Division 2, and even potentially for Appendix 8 of ASME Section X. Recommendations on updating the ASME codes will be considered in this report.


Author(s):  
Shyam Gopalakrishnan ◽  
Ameya Mathkar

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.


Author(s):  
Daniel T. Peters ◽  
Man Pham

There has been a significant amount of discussion of the appropriateness of the design margins from ASME Boiler and Pressure Vessel Code Section VIII Division 3 being applied to the design of HPHT equipment. A technical report has been issued with a first revision which references the use of ASME Section VIII Division 2 and Section VIII Division 3 for design of HPHT equipment above 15 ksi. Additionally, there has been recent pressure testing which attempted to validate the margins used in ASME Section VIII Division 3 and API 17TR8. There has also been a significant amount of discussion that the equipment in HPHT service may be very different from the pressure equipment which utilizes ASME Section VIII Division 3 and the design methods discussed in the standards. This paper will discuss the background of ASME Section VIII Division 3, including an overview of how the standard began, and the types of equipment which were being considered when the document was first drafted. It will also discuss the background of the design margin used in ASME Section VIII Division 3 over the years and how the current margin came into play. It will also discuss the margins used in addition to the margins on the structural capacity of a piece of equipment and how the margins interrelate within the Code. This paper will demonstrate the robust nature of ASME Section VIII Division 3, and its applicability to the design of HPHT equipment.


Sign in / Sign up

Export Citation Format

Share Document