New Common Design Rules for U-Tube Heat Exchangers in ASME, CODAP and UPV Codes

2002 ◽  
Author(s):  
F. Osweiller
Keyword(s):  
Heat Exchangers ◽  
Pressure Vessels ◽  
Design Rule ◽  
Technical Approach ◽  
Design Rules ◽  
Asme Code ◽  
European Code ◽  
Section Viii ◽  
Technical Basis ◽  
Year 2000

In year 2000, ASME Code (Section VIII – Div. 1), CODAP (French Code) and UPV (European Code for Unfired Pressure Vessels) have adopted the same rules for the design of U-tube tubesheet heat exchangers. Three different rules are proposed, based on different technical basis, to cover: • Tubesheet gasketed with shell and channel. • Tubesheet integral with shell and channel. • Tubesheet integral with shell and gasketed with channel or the reverse. At the initiative of the author, a more refined technical approach has been developed, to cover all tubesheet configurations. The paper explains the rationale for this new design rule which is being incorporated in ASME, CODAP and UPV in 2002. This is substantiated with comparisons to TEMA Standards and a benchmark of numerical comparisons.

U-Tube Heat-Exchangers: New Common Design Rules for ASME, CODAP, and EN 13445 CODES

2005 ◽  
Vol 128 (1) ◽  
pp. 95-102
Author(s):  
F. Osweiller
Keyword(s):  
Heat Exchangers ◽  
Design Method ◽  
Pressure Vessels ◽  
European Standard ◽  
Technical Approach ◽  
Design Rules ◽  
Asme Code ◽  
Section Viii ◽  
Technical Basis ◽  
Year 2000

In the year 2000, ASME Code Section VIII—Div. 1, CODAP (French Code) and EN 13445 (European Standard for Unfired Pressure Vessels) have adopted the same rules for the design of U-tube tubesheet heat exchangers. Three different rules were proposed, based on a different technical basis, to cover: —Tubesheet gasketed with shell and channel; —Tubesheet integral with shell and channel; —Tubesheet integral with shell and gasketed with channel or the reverse. At the initiative of the author, a more refined and uniform technical approach has been developed, to cover all tubesheet configurations. The paper explains the rationale for this new design method which has been incorporated recently in ASME, CODAP, and EN 13445. This is substantiated with comparisons to TEMA Standards and a benchmark of numerical comparisons

Fatigue Consideration of Layered Vessels

2020 ◽  
Author(s):  
Kang Xu ◽  
Mahendra Rana ◽  
Maan Jawad
Keyword(s):  
Fatigue Life ◽  
Structural Integrity ◽  
Cost Effective ◽  
Pressure Vessels ◽  
Asme Code ◽  
Section Viii ◽  
Cyclic Service ◽  
Gap Height ◽  
Technical Basis ◽  
Division 2

Abstract Layered pressure vessels provide a cost-effective solution for high pressure gas storage. Several types of designs and constructions of layered pressure vessels are included in ASME BPV Section VIII Division 1, Division 2 and Division 3. Compared with conventional pressure vessels, there are two unique features in layered construction that may affect the structural integrity of the layered vessels especially in cyclic service: (1) Gaps may exist between the layers due to fabrication tolerances and an excessive gap height introduces additional stresses in the shell that need to be considered in design. The ASME Codes provide rules on the maximum permissible number and size of these gaps. The fatigue life of the vessel may be governed by the gap height due to the additional bending stress. The rules on gap height requirements have been updated recently in Section VIII Division 2. (2) ASME code rules require vent holes in the layers to detect leaks from inner shell and to prevent pressure buildup between the layers. The fatigue life may be limited by the presence of stress concentration at vent holes. This paper reviews the background of the recent code update and presents the technical basis of the fatigue design and maximum permissible gap height calculations. Discussions are made in design and fabrication to improve the fatigue life of layered pressure vessels in cyclic service.

Design Formulas of Blind End Closures for High Pressure Vessels

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Maximum Stress ◽  
Accurate Determination ◽  
Pressure Vessels ◽  
Stress Distributions ◽  
Fatigue And Fracture ◽  
Asme Code ◽  
Section Viii

The available design formulas for flat heads and blind end closures in the ASME Code, Section VIII, Divisions 1 and 2 are based on bending theory and do not apply to the design of thick flat heads used in the design of high pressure vessels. This paper presents new design formulas for thickness requirements and determination of peak stresses and stress distributions for fatigue and fracture mechanics analyses in thick blind ends. The use of these proposed design formulas provide a more accurate determination of the required thickness and fatigue life of blind ends. The proposed design formulas are given in terms of the yield strength of the material and address the fatigue strength at the location of the maximum stress concentration factor. Introduction of these new formulas in a nonmandatory appendix of Section VIII, Division 3 is recommended after committee approval.

Fitness-for-Service Strategies for Impulsively Loaded Vessels

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Thomas A. Duffey ◽  
Kevin R. Fehlmann
Keyword(s):  
Pressure Vessels ◽  
Material Behavior ◽  
Remaining Life ◽  
Structural Damping ◽  
Asme Code ◽  
Simplifying Assumptions ◽  
Section Viii ◽  
Repeated Use ◽  
Internal Blast Loading ◽  
Service Strategies

Abstract High-explosive containment vessels are often designed for repeated use, implying predominately elastic material behavior. Each explosive test imparts an impulse to the vessel wall. The vessel subsequently vibrates as a result of the internal blast loading, with amplitude diminishing exponentially in time after a few cycles due to structural damping. Flaws present in the vessel, as well as new flaws induced by fragment impact during testing, could potentially grow by fatigue during these vibrations. Subsequent explosive tests result in new sequences of vibrations, providing further opportunity for flaws to grow by fatigue. The obvious question is, How many explosive experiments can be performed before flaws potentially grow to unsafe limits? Because ASME Code Case 2564-5 (Impulsively Loaded Pressure Vessels) has just been incorporated in Section VIII, Division 3 of the 2019 ASME Boiler and Pressure Vessel Code, evaluation of remaining life and fitness-for-service of explosive containment vessels now draws upon two interrelated codes and standards: ASME Section VIII-3 and API-579/ASME FFS-1. This paper discusses their implementation in determining the remaining life of dynamically loaded vessels that have seen service and are potentially damaged. Results of a representative explosive containment vessel are presented using actual flaw data for both embedded weld flaws and fragment damage. Because of the potentially large number of flaws that can be detected by modern nondestructive inspection methods, three simplifying assumptions and a procedure are presented for conservatively eliminating from further consideration the vast majority of the flaws that possess considerable remaining life.

Evaluation of ASME Pressure Vessel Code Prohibitions on Rod and Bar Stock and Potential Remedies

2014 ◽  
Author(s):  
John J. Aumuller ◽  
Vincent A. Carucci
Keyword(s):  
Pressure Vessels ◽  
Early 20Th Century ◽  
Economic Disadvantage ◽  
User Experiences ◽  
The Public ◽  
Division 1 ◽  
Asme Code ◽  
Billet Material ◽  
Section Viii ◽  
Division 2

The ASME Codes and referenced standards provide industry and the public the necessary rules and guidance for the design, fabrication, inspection and pressure testing of pressure equipment. Codes and standards evolve as the underlying technologies, analytical capabilities, materials and joining methods or experiences of designers improve; sometimes competitive pressures may be a consideration. As an illustration, the design margin for unfired pressure vessels has decreased from 5:1 in the earliest ASME Code edition of the early 20th century to the present day margin of 3.5:1 in Section VIII Division 1. Design by analysis methods allow designers to use a 2.4:1 margin for Section VIII Division 2 pressure vessels. Code prohibitions are meant to prevent unsafe use of materials, design methods or fabrication details. Codes also allow the use of designs that have proven themselves in service in so much as they are consistent with mandatory requirements and prohibitions of the Codes. The Codes advise users that not all aspects of construction activities are addressed and these should not be considered prohibited. Where prohibitions are specified, it may not be readily apparent why these prohibitions are specified. The use of “forged bar stock” is an example where use in pressure vessels and for certain components is prohibited by Codes and standards. This paper examines the possible motive for applying this prohibition and whether there is continued technical merit in this prohibition, as presently defined. A potential reason for relaxing this prohibition is that current manufacturing quality and inspection methods may render a general prohibition overly conservative. A recommendation is made to better define the prohibition using a more measurable approach so that higher quality forged billets may be used for a wider range and size of pressure components. Jurisdictions with a regulatory authority may find that the authority is rigorous and literal in applying Code provisions and prohibitions can be particularly difficult to accept when the underlying engineering principles are opaque. This puts designers and users in these jurisdictions at a technical and economic disadvantage. This paper reviews the possible engineering considerations motivating these Code and standard prohibitions and proposes modifications to allow wider Code use of “high quality” forged billet material to reflect some user experiences.

Rectangular Pressure Vessels of Finite Length

1990 ◽  
Vol 112 (1) ◽  
pp. 50-56 ◽  
Author(s):  
A. E. Blach ◽  
V. S. Hoa ◽  
C. K. Kwok ◽  
A. K. W. Ahmed
Keyword(s):  
Finite Length ◽  
Design Method ◽  
Circular Cross Section ◽  
Pressure Vessels ◽  
Small Deflection ◽  
Asme Code ◽  
Test Pressure ◽  
Section Viii ◽  
Deflection Theory ◽  
Large Deflection Theory

Design Rules in the ASME Code, Section VIII, Division 1, cover the design of unreinforced and reinforced rectangular pressure vessels. These rules are based on “infinitely long” vessels of non-circular cross section and stresses calculated are based on a linearized “small deflection” theory of plate bending. In actual practice, many pressure vessels can be found which are of finite length, often operating successfully under pressures two to three times as high as those permitted under the Code rules cited. This paper investigates the effects of finite length on the design formulae given by the ASME Code, and also a design method based on “large deflection” theory coefficients for short rectangular pressure vessels. Results based on analysis are compared with values obtained from finite element computations, and with experimental data from strain gage measurements on a test pressure vessel.

On the Modelling of Anisotropic Fiber Reinforced Polymer Flange Joints

2021 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Ali K. Vafadar ◽  
Anh-Dung Ngo
Keyword(s):  
Numerical Models ◽  
Design Procedure ◽  
Accurate Method ◽  
Pressure Vessels ◽  
Fiber Reinforced ◽  
Plastic Composite ◽  
Asme Code ◽  
Section Viii ◽  
The One ◽  
Bolted Flange

Abstract Fiber Reinforced Plastic composite flanges have recently experienced a spectacular development in the area of pressure vessels and piping. The current procedures used for the design of these flanges are a major concern because of their inappropriateness to address the anisotropic behavior of composite materials. The current ASME code section X related to the design procedure of composite flanges uses the same analytical method as the one of section VIII division 2 which treat the flanges as isotropic materials such as metallic flanges. This study deals with FRP bolted flange joints integrity and bolt tightness. A new developed analytical FRP model that treats anisotropic flanges with and without a hub is presented. The model is based on the anisotropy and a flexibility analysis of all joint elements including the gasket, bolts and flanges. It is supported experimentally with tests conducted on a real NPS 3 class 150 WN FRP bolted flange. Furthermore, three different numerical models based on 3D anisotropic layered shell and solid element models were conducted to further compare and verify the results obtained from the new developed analytical approach. The results show that the new model has potential to be used as an alternative tool to FEM if an accurate method to analyses the stresses and deformation of problematic FRP bolted joint applications.

Tubesheet Heat Exchangers: New Common Design Rules in UPV, CODAP, and ASME

2000 ◽  
Vol 122 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Francis Osweiller
Keyword(s):  
Pressure Vessel ◽  
Heat Exchangers ◽  
Theoretical Basis ◽  
General Context ◽  
Design Rules ◽  
Analytical Basis ◽  
Section Viii

French CODAP rules devoted to tubesheet heat exchangers were adopted in the 1990s, for the European Unfired Pressure Vessel Standard (UPV). ASME Section VIII—Div. 1 rules issued in July 1998 are based on a similar approach. At the initiative of the author, who is a member of CODAP, UPV, and ASME respective Committees on Heat Exchangers, it has been decided to make the tubesheet design rules of these three codes as consistent as possible. This paper presents the various aspects of this harmonization that covers both the theoretical basis of the rules and the editorial aspect (use of common notations, common tubesheet configurations, common terminology, etc). The main analytical basis of these rules, and their differences are explained. Numerical benchmark calculations, performed on real heat exchangers, outline the significant improvements due to the consistency, with a comparison to current TEMA rules. Use of these common rules in the coming years, both in US and Europe, is discussed in the general context of globalization of the market. [S0094-9930(00)01003-9]

Design Qualification and Manufacturing of Section X Class I Vessels

2002 ◽  
Author(s):  
Douglas Eisberg
Keyword(s):  
Pressure Vessels ◽  
Third Party ◽  
Industrial Safety ◽  
Class I ◽  
Sound Design ◽  
Fiber Reinforced ◽  
Safety Standards ◽  
Design Qualification ◽  
Asme Code ◽  
Section Viii

Over the past several years, many industries have grown to recognize that Fiber Reinforced Plastic (FRP) pressure vessels must be built to established industrial safety standards to help ensure consistently safe products. End Users and Engineers familiar with Section VIII of the ASME Code typically turn to Section X as the standard recognized to govern the fabrication of fiber-reinforced vessels. However there tends to be confusion concerning Section X and how design integrity is maintained. There is a belief held by some that a composite pressure vessel designed in accordance with the Section X, Class I meets the essence of the Code. The feeling is that complete compliance is an unnecessary expense and third party certification is of minimal value. Section X is very specific in pointing out the fundamental error in this thinking. Section X recognizes that, unlike metal construction, the fabricator of a fiberglass vessel is responsible for the creation of a new and very temperamental material every time a part is fabricated. With this chance of inconsistency, even a fundamentally sound design can be executed poorly and with disastrous results. The purpose of this paper will be to describe the design and procedure qualification process used for Class I pressure vessels and how the integrity of the design in maintained throughout the fabrication of ASME Code Stamped pressure vessels.

Design of Threaded Closures for High Pressure Screw Plug Heat Exchangers Designed to ASME Section VIII Div. 2

2017 ◽  
Author(s):  
Haresh K. Sippy ◽  
Dipak K. Chandiramani
Keyword(s):  
High Pressure ◽  
Heat Exchangers ◽  
Pressure Vessels ◽  
Typical Application ◽  
High Pressure And Temperature ◽  
Heat Transfer Efficiency ◽  
Allowable Stresses ◽  
Section Viii ◽  
Screw Threads ◽  
Good Access

Threaded closures for pressure vessels have been in use for decades. Much work has been done to develop safe threaded closures. Threaded closures are very advantageous when there is a need for opening the vessel at intervals for maintenance purposes. Heat Exchangers are a typical application where there is a need for opening the vessel to get good access to the inside and outside of the tubes for mechanical cleaning, thus maintaining heat transfer efficiency. These are known as Screw Plug Heat Exchangers and are basically U-tube heat exchangers. The tube side normally operates at high pressure and temperature and is closed by a threaded end closure. Two problems are often encountered in screw plug heat exchangers. These are: 1. Leakage through the gasket at the tubesheet causing intermixing of shell side and tube side fluids, which is unacceptable 2. Jamming of the threaded plug due to deformation of channel barrel In an earlier paper (PVP2016-63137) these problems were studied for a vessel designed to ASME Section VIII Div. 1. It was found that leakage through the tubesheet gasket could be eliminated by changing the gasket to a grooved metal gasket with covering layers as defined in ASME B16.20. Preventing leakage from the tubesheet gasket is extremely necessary to get the ultra-low sulphur requirements for clean fuel. In the work reported in this paper, a procedure for obtaining leak-free performance on a vessel designed to ASME Section VIII Div. 2 was developed and verified using a prototype. Code formulae for calculation of thickness of various parts normally consider only the need to limit the component stress to be within allowable limits defined in the Code. Allowable stresses for Section VIII Div. 2 construction may be about 18 % higher than the allowable stress for Section VIII Div. 1 construction at design temperature, thereby allowing thinner sections for the same design conditions. As the thinner sections would deform more, the likelihood of jamming of the end cover could be more severe in ASME Section VIII Div. 2 constructions. Hence this study was additionally undertaken to verify the adequacy of the earlier proposed design methodology, i.e., use of an additional steel ring shrunk fit to the end of the channel to prevent flaring of the channel and jamming of screw threads, for Section VIII Div. 2 constructions.

Sign in / Sign up

Export Citation Format

Share Document