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

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

Author(s):  
F. Osweiller

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.


Author(s):  
Kang Xu ◽  
Mahendra Rana ◽  
Maan Jawad

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.


1990 ◽  
Vol 112 (1) ◽  
pp. 50-56 ◽  
Author(s):  
A. E. Blach ◽  
V. S. Hoa ◽  
C. K. Kwok ◽  
A. K. W. Ahmed

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.


2018 ◽  
Vol 69 (8) ◽  
pp. 1954-1961
Author(s):  
Valeriu V. Jinescu ◽  
Georgeta Urse ◽  
Angela Chelu

We have provided a comparative analysis of the current international computing standards (European Standard EN 13445-3; ASME-Code, Section VIII, Division 2; British Standard (PD 5500: 2009)) that take into consideration only the static loading of flanges and bolts, if the temperatures of the flanges, bolts and sealing gasket are equal to each other and lower than creep temperature. The paper has put forth relations for completion the calculation method for flange joints in situations not taken into consideration by standards, namely: � static loading if flange temperature and bolt temperature are different; -thermal transient loading; � creep stress; � fatigue loading in the general case of a sequence of blocks of normal stresses. Furthermore, relationships have been proposed for the calculation of the maximum allowable difference between a flange and a bolt so as to ensure both the tightness and the mechanical strength of the flange joint.


Author(s):  
Fernando Lidonnici ◽  
Corrado Delle Site

Tubesheets are usually designed according to different national or international design codes. The great majority of these standards is based on Gardner’s theory, elaborated more than 60 years ago. On the other hand these pressure components are critical in heat exchanger design, because they are subject to characteristic service damages which require a correct dimensioning and appropriate inspections during service. This paper is aimed at comparing the different design methods, analyzing the theoretical background behind the rules. Main focus is made to the alternative design method contained in Annex J of the European Standard EN13445-3. With reference to the typical configuration of a fixed tubesheet exchanger with flanged connections, the results of the different design approaches are compared in order to find out the optimal configuration. Benchmark examples are carried out using a commercial computer code with reference to heat exchangers with the tubesheets welded to the shell and bolted to the channel. The results show the advantage of using Annex J which allows smaller thicknesses of the tubesheet in respect of the conventional approach used by TEMA, ASME Section VIII and EN 13445-3 clause 13.


2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez

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.


Author(s):  
Yongjun Chen ◽  
Jinyang Zheng ◽  
Guide Deng ◽  
Yuanyuan Ma ◽  
Guoyou Sun

Explosion containment vessels (ECVs), which can be generally classified into three categories, i.e., multiple use ECVs and one-time use ECVs, single-layered ECVs and multi-layered ECVs, metallic ECVs and composite ECVs according to the usage, structural form and the bearing unit, respectively, are widely used to completely contain the effects of explosions. There are fundamental differences between statically-loaded pressure vessels and ECVs that operate under extremely fast loading conditions. Conventional pressure design codes, such as ASME Section VIII, EN13445 etc., can not be directly used to design ECVs. So far, a lot of investigations have been conducted to establish design method for ECVs. Several predominant effects involved in the design of ECVs such as scale effect, failure mode and failure criteria are extensively reviewed. For multiple use single-layered metallic ECVs, dynamic load factor method and AWE method are discussed. For multiple use composite ECVs, a minimum strain criteria based on explosion experiments is examined. For one-time use ECVs, a strain limit method proposed by LANL and a maximum strain criteria obtained by Russia are discussed for metallic vessel and composite vessel, respectively. Some improvements and possible future work in developing design criterion for ECVs are recommended as a conclusion.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Thomas A. Duffey ◽  
Kevin R. Fehlmann

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.


Author(s):  
John J. Aumuller ◽  
Vincent A. Carucci

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.


Author(s):  
Abdel-Hakim Bouzid ◽  
Ali K. Vafadar ◽  
Anh-Dung Ngo

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.


Sign in / Sign up

Export Citation Format

Share Document