Proposal of New Upper Limit of Hydrostatic Test Pressure in KT-3 of ASME Section VIII Division 3

2018 ◽  
Author(s):  
Susumu Terada
Keyword(s):  
Test Results ◽  
Design Factor ◽  
Burst Test ◽  
Increase Wall Thickness ◽  
Upper Limit ◽  
General Yielding ◽  
Test Pressure ◽  
Section Viii ◽  
Division 2 ◽  
Design Pressure

The current upper limit of hydrostatic test pressure in KT-3 of ASME Sec. VIII Division 3 is determined by general yielding through the thickness obtained by Nadai’s equation with a design factor of 0.866 (= 1.732/2). On the other hand, the upper limit of hydrostatic test pressure in 4.1.6 of the ASME Sec. VIII Division 2 is determined by general yielding through the thickness with a design factor of 0.95. In cases where a ratio of hydrostatic test pressure to design pressure of 1.43 similar to PED (Pressure Equipment Directive) is requested, the upper limit of hydrostatic test pressure may be critical for vessel design when material with a ratio of yield strength to tensile strength less than 0.7 is used. In order to satisfy the requirements in KT-3, it is necessary to decrease design pressure or increase wall thickness. Therefore, it is proposed to change the design factor of intermediate strength materials to obtain the upper limit of hydrostatic test pressure. In this paper, a new design factor to obtain the upper limit of hydrostatic test pressure is proposed and the validity of this proposal was investigated by burst test results and elastic-plastic analysis.

Development of Alternate Methods for Establishing Design Margins for ASME Section VIII Division 3

2008 ◽  
Author(s):  
Susumu Terada
Keyword(s):  
High Strength ◽  
Test Results ◽  
Burst Test ◽  
Section Viii ◽  
Lower Ratio ◽  
Design Pressure ◽  
Design Margin

The design margin against collapse for Division 3 is based on Nadai’s equation. For high strength materials (the ratio of Sy/Su is more than 0.9) this method is adequate. However for the material with lower ratio of Sy/Su than 0.9 this method has additional margin from entire yielding through the thickness to collapse. The experimental burst test results for closed-end cylinder show the excessive margin for these materials. Therefore the development of alternate methods for establishing design margins for all materials is desirable. In this paper the experimental burst test results, case study of various methods (Div.2 rewrite, current Div.3 and proposed method) for design pressure are investigated.

Comparison of Elastic-Plastic Analysis and Experimental Result for Locally Thinned Pipe

2010 ◽  
Author(s):  
Wolf Reinhardt ◽  
Xinjian Duan
Keyword(s):  
Design Method ◽  
Experimental Result ◽  
Plastic Limit ◽  
Straight Pipe ◽  
Burst Test ◽  
Elastic Plastic ◽  
Plastic Analysis ◽  
Plastic Limit Analysis ◽  
Section Viii ◽  
Design Pressure

The result of a burst test of a thinned straight pipe with local thinning is reported. The locally thinned region had a thickness well below the NB-3600 pressure based Design thickness. The burst pressure is compared with the maximum Design pressure obtained from a variety of elastic-plastic analysis methods, such as plastic limit analysis and the Section VIII Div. 2 elastic-plastic design method.

Development of Alternate Methods for Establishing Design Margins for ASME Section VIII Division 3: Part 2

2009 ◽  
Author(s):  
Susumu Terada
Keyword(s):  
Cylindrical Shell ◽  
Spherical Shell ◽  
High Strength ◽  
Test Results ◽  
Burst Test ◽  
Elastic Plastic ◽  
Plastic Analysis ◽  
Section Viii ◽  
Lower Ratio ◽  
Design Margin

The design margin against collapse for Division 3 is based on Nadal’s equation. For high strength material this method is adequate. However for material with a lower ratio of Sy/Su this method has additional margin from yielding through the thickness to final collapse or burst. The experimental burst test results for closed-end cylinder show the excessive margin for these materials as stated in former paper. Therefore the development of alternate methods for establishing design margin for all materials is desirable. The design margin of 1.5 in equation for open-end cylindrical shell and spherical shell in current code is different from that of 1.732 for closed-end cylindrical shell. The design margin of elastic-plastic analysis is 1.732. Therefore the consistent design margins of equations and elastic-plastic analysis for open-end cylindrical shells and spherical shells are also desirable. In this paper new equations for design pressure of cylindrical shell and spherical shell are proposed by investigation of burst test results and case studies of various methods.

General Criteria and Evaluations for the Selection of ASME Section VIII, Division 1 or 2 for New Construction Pressure Vessels

2020 ◽  
Author(s):  
Nathan Barkley ◽  
Matt Riley
Keyword(s):  
Pressure Vessels ◽  
Design Rules ◽  
Advantages And Disadvantages ◽  
Division 1 ◽  
New Construction ◽  
Section Viii ◽  
Division 2 ◽  
Design Pressure ◽  
Selection Of

Abstract For new ASME pressure vessel designs that have a design pressure less than 10,000 psi (70 MPa), it is commonly questioned whether Section VIII, Division 1 or Division 2 should be used as the code of construction. Each code offers specific advantages and disadvantages depending on the specific vessel considered. Further complicating the various considerations is the new Mandatory Appendix 46 of Division 1 which allows the design rules of Division 2 to be used for Division 1 designs. With the various options available, determining the best approach can be challenging and is often more complex than only determining which code provides the thinnest wall thickness. This paper attempts to address many of the typical considerations that determine the use of Division 1 or Division 2 as the code of construction. Items to be considered may include administrative burden, certification process, design margins, design rules, and examination and testing requirements. From the considerations presented, specific comparisons are made between the two divisions with notable differences highlighted. Finally, sample evaluations are presented to illustrate the differences between each code of construction for identical design conditions. Also, material and labor estimates are compiled for each case study to provide a realistic comparison of the expected differential cost between the construction codes.

A Comparative Study of Radial Nozzle Criteria; Section VIII, Division 2, Part 4.5.5 to Part 5.2.2

2021 ◽  
Author(s):  
Craig Boyak
Keyword(s):  
Comparative Study ◽  
Elastic Analysis ◽  
Design Methodologies ◽  
Section Viii ◽  
Division 2 ◽  
Radial Nozzle ◽  
Design Pressure

Abstract A study is presented which compares nozzle thickness requirements based ASME Section VIII, Division 2, Parts 4 and 5[1]. Specifically, the simplified geometry of a set-in, radial nozzle without inward projection or repad is considered. The comparative technique considers a design pressure at the capacity of the shell and identifies the minimum nozzle thickness that satisfies applicable stress limits. For Part 4, the methodology of 4.5.5 is used. For Part 5, the elastic method in 5.2.2 is used. The study employs these techniques for R/t geometries of 20 to 180 and d/D ratios of 0.01 to 0.3. The comparison indicates elastic analysis Part 5 methods can improve the design from that of Part 4 over some, but not all, configurations within the study’s scope. The bounds of where the elastic analysis Part 5 methods benefit are identified. In the process of the study’s effort, numerous responses are identified and compared between design methodologies. The comparison is one of needed nozzle thickness for similar geometries. Behavior responses are shown from the range of configurations in the large simulation set created by the Part 5 method. For the Part 4 response, charts are shown that identify the required nozzle thickness based on the varying reinforcing limit logic employed in that method.

Failure Mode Determination of API 12F Shop-Welded Tanks with a New Roof-to-Shell Junction Detail

2021 ◽  
Author(s):  
Heyi Feng ◽  
Sukru Guzey
Keyword(s):  
American Petroleum Institute ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Safe Operation ◽  
Element Analysis ◽  
Nominal Capacity ◽  
Section Viii ◽  
Division 2 ◽  
Design Pressure

Abstract The API 12F is the specification for vertical, aboveground shop-welded storage tanks published by the American Petroleum Institute (API). The nominal capacity for the twelve tank designs given in the current 13th edition of API 12F ranges from 90 bbl. (14.3 m3) to 1000 bbl. (159 m3). The minimum required component thickness and design pressure levels are also provided in the latest edition. This study is a part of a series research project sponsored by API that dedicates to ensure the safe operation of API 12 series storage tanks. In this study, the twelve API 12F tank designs presented in the latest edition are studied. The elastic stress analysis was conducted following the procedures presented in the ASME Boiler and Pressure Vessel Code 2019, Section VIII, Division 2 (ASME VIII-2). The stress levels at the top, bottom, and cleanout junctions subject to the design pressures are determined through finite element analysis (FEA). The bottom uplift subjected to design pressures are obtained, and the yielding pressure at the roof-shell and shell-bottom junctions are also determined. The specific gravity of the stored liquid is raised from 1.0 to 1.2 in this study. A new roof-shell attachment detail is proposed, and a 0.01 in. (0.254 mm) gap between the bottom shell course and the bottom plate is modeled to simulate the actual construction details. In addition, the flat-top rectangular cleanout presented in the current edition of API 12F is modeled.

Limit Pressures of Cylindrical and Spherical Shells

2000 ◽  
Vol 123 (3) ◽  
pp. 288-292 ◽  
Author(s):  
Arturs Kalnins ◽  
Dean P. Updike
Keyword(s):  
Geometric Parameter ◽  
Cylindrical Shells ◽  
Length Effect ◽  
Spherical Shells ◽  
Simply Supported ◽  
Limit Pressure ◽  
Section Viii ◽  
Division 2

Tresca limit pressures for long cylindrical shells and complete spherical shells subjected to arbitrary pressure, and several approximations to the exact limit pressures for limited pressure ranges, are derived. The results are compared with those in Section III-Subsection NB and in Section VIII-Division 2 of the ASME B&PV Code. It is found that in Section VIII-Division 2 the formulas agree with the derived limit pressures and their approximations, but that in Section III-Subsection NB the formula for spherical shells is different from the derived approximation to the limit pressure. The length effect on the limit pressure is investigated for cylindrical shells with simply supported ends. A geometric parameter that expresses the length effect is determined. A formula and its limit of validity are derived for an assessment of the length effect on the limit pressures.

The effect of proof testing on the shakedown behaviour of pressure vessel nozzles

1994 ◽  
Vol 29 (2) ◽  
pp. 81-92 ◽  
Author(s):  
N I Crawley ◽  
D N Moreton ◽  
D G Moffat ◽  
A F Tolley
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Steel Type ◽  
Pressure Cycling ◽  
Proof Testing ◽  
Pressure Tests ◽  
Test Pressure ◽  
Design Pressure

Cyclic internal pressure tests were conducted over several hundreds of cycles at pressures up to and in excess of the calculated proof test pressure on two nominally ‘identical’, stainless steel type 316 flush 90 degrees pressure vessel nozzles, designed and manufactured to BS 5500. Prior to this pressure cycling, one vessel was subjected to the required proof test of 1.25 times the design pressure. Significant incremental straining was recorded in the non-proof tested vessel during cycling at all pressures above the first yeild pressure (0.336 × design pressure). For the proof tested vessel significant incremental straining was not recorded during cycling until 15 percent above the design pressure.

Three Years of Experience With Random Urinary Homovanillic and Vanillylmandelic Acid Levels in the Diagnosis of Neuroblastoma

PEDIATRICS ◽  
1987 ◽  
Vol 79 (2) ◽  
pp. 203-205
Author(s):  
Mendel Tuchman ◽  
Margaret L. R. Ramnaraine ◽  
William G. Woods ◽  
William Krivit
Keyword(s):  
False Positive ◽  
Homovanillic Acid ◽  
False Negative ◽  
False Negative Rate ◽  
Urine Samples ◽  
Vanillylmandelic Acid ◽  
Test Results ◽  
Upper Limit ◽  
Positive Results ◽  
Rule Out

During the last 3 years, random urine samples from 408 patients were tested for elevated homovanillic acid (HVA) and vanillylmandelic acid (VMA) levels to rule out the diagnosis of neuroblastoma. Thirty-seven of these patients had elevated HVA and/or VMA levels, and neuroblastoma was subsequently diagnosed. In three additional patients with negative test results (normal HVA and VMA levels), tumors were subsequently diagnosed (false-negative rate of 7.5%). Ten percent of the patients with neuroblastoma had normal HVA and 27.5% had normal VMA levels at the time of diagnosis. Only one patient (2.5%) with neuroblastoma had elevated VMA levels in the presence of normal HVA levels. More than 60% of the patients with neuroblastoma had urinary HVA and/or VMA levels higher than twice the upper limit of normal. No false-positive results were encountered. Age and stage distributions of the patients are shown, and the significance of the results is discussed.

Applicability of Design Rules for Openings in Shells, ASME B&PV Code, Section VIII, Division 2 - A Case Study

2021 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Krishnakant V. Pudipeddi ◽  
Subramanyam V. R. Sripada
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Element Analysis ◽  
Design Rules ◽  
Area Method ◽  
Replacement Method ◽  
Local Stresses ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

Abstract The Pressure-Area method is recently introduced in the ASME Boiler and Pressure Vessel (B&PV) Code, Section VIII, Division 2 to reduce the excessive conservatism of the traditional area-replacement method. The Pressure-Area method is based on ensuring that the resistive internal force provided by the material is greater than or equal to the reactive load from the applied internal pressure. A comparative study is undertaken to study the applicability of design rules for certain nozzles in shells using finite element analysis (FEA). From the results of linear elastic FEA, it is found that in some cases the local stresses at the nozzle to shell junctions exceed the allowable stress limits even though the code requirements of Pressure-Area method are met. It is also found that there is reduction in local stresses when the requirement of nozzle to shell thickness ratio is maintained as per EN 13445 Part 3. The study also suggests that the reinforcement of nozzles satisfy the requirements of elastic-plastic stress analysis procedures even though it fails to satisfy the requirements of elastic stress analysis procedures. However, the reinforcement should be chosen judiciously to reduce the local stresses at the nozzle to shell junction and to satisfy other governing failure modes such as fatigue.

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