Limit Design of Condenser Hotwell Floors

1975 ◽  
Vol 97 (4) ◽  
pp. 628-632
Author(s):  
A. I. Soler
Keyword(s):  
Flat Plate ◽  
Elastic Plate ◽  
Pressure Vessel ◽  
Plate Theory ◽  
Limit Load ◽  
Uniform Pressure ◽  
Plastic Plate ◽  
Rigid Plastic ◽  
Division 1 ◽  
Section Viii

Rigid plastic plate theory is used to determine the limit load for a pipe-supported flat plate loaded by uniform pressure. The solution is applied to design of condenser hotwell floors under hydrotest loading. A comparison is made with a formula for design of similar configurations suggested in Section VIII, Division 1 of the ASME Pressure Vessel Code, and in texts on elastic plate theory.

The Applicability of the ASME Boiler and Pressure Vessel Code, Section XII, Transport Tanks, for Use in U.S. Federal Maritime Regulations

2010 ◽  
Author(s):  
Allen Selz ◽  
Daniel R. Sharp
Keyword(s):  
Pressure Vessel ◽  
Road Transport ◽  
Pressure Vessels ◽  
Department Of Transportation ◽  
The Road ◽  
Dangerous Goods ◽  
Division 1 ◽  
The Us ◽  
Section Viii ◽  
Marine Applications

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.

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.

Expanded, and Welded-and-Expanded Tube-to-Tubesheet Joints

1992 ◽  
Vol 114 (2) ◽  
pp. 157-165 ◽  
Author(s):  
S. Yokell
Keyword(s):  
Pressure Vessel ◽  
Joint Strength ◽  
Small Diameter ◽  
High Strength ◽  
Interfacial Stress ◽  
Uniform Pressure ◽  
Plastic Tube ◽  
Before And After ◽  
Section Viii ◽  
Rolling Torque

This paper discusses some practical aspects of expanded and welded-and-expanded tube-to-tubesheet joints. It reviews elastic-plastic tube expanding theory, which it uses as the basis for setting pressures for uniform-pressure expanding and for estimating residual interfacial stress at the tube-hole interface. It addresses uniform-pressure-expanded tube joint strength and the problem of correlating of roller-expanded joint strength with wall reduction and rolling torque. It advocates two-stage expanding: 1) applying just sufficient pressure or torque to create firm tube-hole contact over substantially the tubesheet thickness; and 2) re-expanding at full pressure or torque. It points out the advantages of segregating heats of tubing and mapping the tube-heat locations. It recommends non-TEMA Standard (and non-HEI Power Plant Standard) grooves for grooved-hole joints made by roller-expanding, when the tubes are thin-walled, high-strength, low-elastic-modulus, and for joints made by uniform-pressure expanding [1, 2]. It states what to examine when considering grooves for small-diameter tubes. It reviews tube-to-tubesheet welding requirements and discusses welding before and after expanding. It suggests TEMA revise its standards to define strength and seal welds and urges the ASME Boiler and Pressure Vessel Code Committee (the Code Committee) to incorporate the TEMA definition in Section VIII of the ASME Boiler and Pressure Vessel Code (the Code) [3]. It makes recommendations for pressure and leak-testing. The work shows why welded-and-expanded joints should be full-strength expanded and why expansion length should equal the tubesheet thickness minus 1/8 in. (approximately 3 mm) rather than the lengths the TEMA and HEI Standards permit.

A more accurate method for predicting the stresses in a flat steel ribbon wound pressure vessel

1999 ◽  
Vol 213 (8) ◽  
pp. 787-793 ◽  
Author(s):  
J Y Zheng ◽  
P Xu ◽  
L Q Wang ◽  
G H Zhu
Keyword(s):  
Pressure Vessel ◽  
Accurate Method ◽  
Pressure Vessels ◽  
Friction Model ◽  
Interfacial Friction ◽  
Division 1 ◽  
Helical Winding ◽  
Section Viii ◽  
Flat Steel ◽  
Steel Ribbon

Flat steel ribbon wound pressure vessels have been adopted by the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 and Division 2. An excellent safety and service record has been built up in the past 34 years. Based on the interfacial friction model proposed by Zheng [1], a more accurate method for predicting the stresses in a flat steel ribbon wound pressure vessel is offered in this paper, taking account of the axial displacement, the change in the helical winding angle, the interfacial friction between ribbon layers and the effect of lamination. Comparison between experimental results of five test vessels with an inside diameter varying from 350 to 1000 mm, four different helical winding angles (18, 24, 27 and 30°), two width—thickness ratios of the ribbon (20 and 22.86) and results of calculation using the stress formulae available demonstrates that the method in this paper is more accurate and that interfacial friction gives a marked strengthening contribution to the axial strength of the vessel.

Analysis of Pressure Vessel Sloshing

2006 ◽  
Author(s):  
S. M. McGuffie ◽  
M. A. Porter
Keyword(s):  
Pressure Vessel ◽  
Time History ◽  
Transient Time ◽  
Closed Form Solutions ◽  
3 Dimensional ◽  
Fluid Sloshing ◽  
History Analysis ◽  
Division 1 ◽  
Section Viii ◽  
Computational Fluid Dynamics Cfd

ASME BPVC Section VIII Division 1 Paragraph UG-22 (f) requires consideration of the loadings from seismic conditions. For a vessel containing a fluid, the loading due to sloshing must be considered. ASCE Standard 7-02 (Section 9.14.7.3) states that a damping value of 0.5% can be used to account for the fluid sloshing. This can lead to an overly conservative design by over-estimating the loads on the tank structure. A time-history analysis was performed on a horizontally mounted pressure vessel experiencing 3-axis time history loads in order to determine if this method is more accurate in determining the loads. The analysis employed a 3-dimensional computational fluid dynamics (CFD) model, using transient time-history techniques. The reactions at the mounting locations were compared to the reactions computed using closed form solutions, demonstrating good correlation. The results show that CFD is an excellent tool for investigating seismic sloshing loads in vessels.

Background and Summary of Revisions to Appendix M of ASME Section VIII, Division 1: Stop Valves Located in the Pressure Relief Path

2004 ◽  
Author(s):  
Richard J. Basile ◽  
Clay D. Rodery
Keyword(s):  
Pressure Vessel ◽  
White Paper ◽  
Pressure Vessels ◽  
Relief Valve ◽  
Pressure Relief ◽  
Stop Valve ◽  
Division 1 ◽  
Section Viii ◽  
Current Code ◽  
Petrochemical Industries

Appendix M of Section VIII, Division 1 of the ASME Boiler and Pressure Vessel Code[1] provides rules for the use of isolation (stop) valves between ASME Section VIII Division 1 pressure vessels and their protective pressure relieving device(s). These current rules limit stop valve applications to those that isolate the pressure relief valve for inspection and repair purposes only [M-5(a), M-6], and those systems in which the pressure originates exclusively from an outside source [M-5(b)]. The successful experience of the refining and petrochemical industries in the application and management of full area stop valves between pressure vessels and pressure relief devices suggested that the time was appropriate to review and consider updates to the current Code rules. Such updates would expand the scope of stop valve usage, along with appropriate safeguards to ensure that all pressure vessels are provided with overpressure protection while in operation. This white paper provides a summary of the current Code rules, describes the current practices of the refining and petrochemical industries, and provides an explanation and the technical bases for the Code revisions.

Heat Treatment of Fabricated Components and the Effect on Properties of Materials

2019 ◽  
Author(s):  
Shyam Gopalakrishnan ◽  
Ameya Mathkar
Keyword(s):  
Heat Treatment ◽  
Pressure Vessel ◽  
Test Specimen ◽  
Stress Relieving ◽  
Division 1 ◽  
Asme Code ◽  
Alloy Steels ◽  
Section Viii ◽  
Properties Of Materials ◽  
Division 2

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.

Improving Flange Designs Based on ASME Section VIII Div. 1, Appendix 2

2020 ◽  
Author(s):  
Chris W. Cary
Keyword(s):  
Pressure Vessel ◽  
End User ◽  
Analysis Methods ◽  
Division 1 ◽  
Bolt Stress ◽  
Section Viii ◽  
Input Variables ◽  
Improved Methods ◽  
Very High ◽  
Design Pressure

Abstract Although improved methods for flange design have been under development for many years, ASME Boiler and Pressure Vessel Code Section VIII, Division 1 Appendix 2 continues to be the basis for the design of most custom pressure vessel flanges. While the method does a reasonably good job of calculating flange stress and rotation from the design loadings, it does not closely constrain some of the design input variables, such as gasket width and geometry, allowing the designer to produce poorly-performing designs. Also, the gasket loading factors (m & y values) have long been recognized as needing improvement. These weaknesses occasionally result in flanges which are difficult to seal, even with very high assembly bolt stress. In response to these weaknesses in the Appendix 2 method, various attempts to improve the method may be employed, and are sometimes required by end-user specifications. This paper provides an assessment of the effectiveness of various improvement techniques by examining the actual effects on flange designs across a range of diameter and design pressure, and makes recommendations for the use of such techniques. The analysis methods in PCC-1 and WRC Bulletin 538 are used as the basis of the evaluation, with a focus on gasket stress as fundamental to sealing.

Reliability Factors and Tightness of Tube-to-Tubesheet Joints

1996 ◽  
Vol 118 (2) ◽  
pp. 137-141 ◽  
Author(s):  
Z. F. Sang ◽  
Y. Z. Zhu ◽  
G. E. O. Widera
Keyword(s):  
Pressure Vessel ◽  
Division 1 ◽  
Asme Code ◽  
Section Viii ◽  
Preliminary Study

The main purpose of this paper is to provide an applicable method to establish reliability factors for expanded tube-to-tubesheet joints. The paper also reports on the results of a preliminary study to validate experimentally the reliability efficiencies listed in Table A-2 of Appendix A of Section VIII, Division 1, of the Boiler and Pressure Vessel Code (ASME, 1986), and tightness of expanded tube-tubesheet joints. A comparison between the actual reliability factors fr determined from testing the damage strength of the joint and calculated according to Appendix A-4 of the ASME Code and those of Table A-2 is carried out. The results are discussed in light of the restrictions inherent in Table A-2. It is confirmed that some existing values of fr are conservative, while others are less so.

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