Computer Based Process Piping Stress Analysis: ASME B31.3 Appendix S — Example S1

2006 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Petroleum Refinery ◽  
Operating Temperature ◽  
The Past ◽  
Analysis Process ◽  
Process Piping ◽  
Piping Systems ◽  
Computer Based ◽  
Temperature And Pressure ◽  
Design Pressure

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. Also as B31.3 continued to pass thru standards organizations from ASA, ANSI, to ASME, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous over the past few decades in several areas. Ambiguities such as what temperatures and pressures are to be used during the pipe stress analysis process is addressed but apparently not clearly enough to make the point; the prevailing practice in the industry is to use the design pressure and temperature; but this is an incorrect inference from the Code. The misunderstandings as to the few, albeit very important, purposed uses for the design pressure and design temperature also appear to be prevalent in the industry. This paper describes some of these subtle yet possibly radical concepts that were included in the ASME B31.3-2004 Appendix S Example Sl. This paper discusses: • the design and analysis procedures in defining when the design conditions are actually to be used; • when and in what manner the most severe set of operating temperature and pressure is to be used; • and the debates that lasted over a decade to finally include into the Code such “seemingly simple” examples that address computer based stress analysis.

Computer Based Process Piping Stress Analysis: ASME B31.3 Appendix S — Example S2

2006 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Operating Temperature ◽  
Stress Range ◽  
Explicit Equation ◽  
The Past ◽  
Process Piping ◽  
Piping Systems ◽  
Sustained Loads ◽  
Computer Based ◽  
Temperature And Pressure

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. Also as B31.3 continued to pass thru standards organizations from ASA, ANSI, to ASME, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous over the past few decades in several areas. The displacement stress range, SE, has always been explicitly defined by both verbiage and equation. Yet, the sustained condition(s) stress, SL, is mentioned not with an explicit equation but with a statement that the sustained stress shall be limited by the allowable stress at the corresponding operating temperature, Sh. Also one might infer from the vague verbiage in the Code that there is only one sustained condition; this would also be an incorrect inference. Also, assumptions would then have to be made as to which supports are allowed to be included in a sustained analysis based on whether the piping “lifts-off” any of the pipe supports during the corresponding operating condition. This paper describes the subtle yet possibly radical concepts that are included in the (recently approved for inclusion into) ASME B31.3-2006 Appendix S Example S2. This paper discusses: • when and in what manner the most severe set of operating temperature and pressure is to be used; • the concept of “sustained condition” and multiple “anticipated” sustained conditions; • determining the support scenario(s) for each anticipated sustained condition; • establishing the most severe sustained condition to evaluate and determine the stress due to sustained loads, SL; • utilizing an equation with sustained stress indices to evaluate SL; • establishing the least severe sustained condition and its effect in determining the largest displacement stress range, SE.

Computer Piping Analysis, ASME B31.3 Appendix S: Example S3 — Moment Reversal

2007 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Petroleum Refinery ◽  
Axial Stress ◽  
Piping System ◽  
Stress Range ◽  
Analysis Software ◽  
Process Piping ◽  
Piping Systems ◽  
Operating Stress ◽  
The Impact

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. From its inception until recent times, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous in several areas. This paper describes some of these subtle concepts that are included in the Code 2006 Edition for Appendix S Example S3. This paper discusses: • the effect of moment reversal in determining the largest Displacement Stress Range, • the impact of the average axial stress caused by displacement strains on the Example S3 piping system and the augmenting of the Code Eq. (17) thereto, • a brief comparison of Example S3 results to that of the operating stress range evaluated in accordance with the 2006 Code Appendix P Alternative Requirements.

ASME B31.3 Appendices P and S: Compensating for Shortcomings

2008 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Stress Range ◽  
Analysis Software ◽  
Process Piping ◽  
Computer Based

The 2004 edition of ASME B31.3 Process Piping Code [1] introduced both Appendix P and Appendix S Example 1; Examples 2 and 3 were included in the 2006 edition. Appendix P is to illustrate a nearly computer stress analysis basis by defining alternative rules for displacement stress range evaluation, and Appendix S contains examples describing how to satisfy the requirements of B31.3 when performing computer based stress analysis. As is possible with any extensive addition to any code, these first offerings contained shortcomings either explicitly or by lack of clarity. This paper discusses some of these issues, provides workarounds when using today’s commercially available piping stress analysis software, and proposes revisions to both Appendices for the 2010 edition of the B31.3 Process Piping Code.

Bolted Flange Joints Under External Moments: An Analysis Using the Compound Gasket Approach for Spiral Wound Gaskets

2007 ◽  
Author(s):  
Trevor G. Seipp ◽  
Christopher Reichert ◽  
Barry Messer
Keyword(s):  
Piping System ◽  
Bending Moments ◽  
Flange Joint ◽  
Pressure Method ◽  
The Past ◽  
External Moment ◽  
Piping Systems ◽  
Bolted Flange ◽  
Design Pressure ◽  
Component Rating

It is common to rate a piping system to its weakest component to maximize flexibility for future operations. In many situations, the bolted flange joint is the lowest rated component. Rating a system for its full flange rating reduces the flange’s capacity to carry external bending moments. In the past, moments on flanged joints have been evaluated by using the concept of equivalent pressure, first presented in the Kellogg Design of Piping Systems. Operating moments are converted to an equivalent pressure. This equivalent pressure is added to the design pressure and compared against a limit. According to conventional practices, the design pressure plus the equivalent pressure must not exceed the rating pressure. Consequently, designing up to the flange rating pressure presents an issue, since no margin is left for the effects of external moments on flange joints. Depending on the circumstances, many designers have compensated by permitting the combined design pressure and equivalent pressure to be as high as twice the flange rating. In this paper, the authors demonstrate a robust methodology to define an appropriate limit for operating moments on bolted flange joints. Using the calculation methodologies of EN-1591-1, the authors calculate the maximum external moment that various classes of standard ASME B16.5 flanges (for Group 1.1 materials) can tolerate over a range of temperatures and present a representative sample. Conclusions are drawn about appropriate limits for moments on flanges and are compared to results using the equivalent pressure method.

Rural Women in Colombia, Facing the Postconflict: A Qualitative Synthesis

2021 ◽  
pp. 152483802199598
Author(s):  
Daniel Felipe Martín Suárez-Baquero ◽  
Martha Patricia Bejarano-Beltrán ◽  
Jane Dimmitt Champion
Keyword(s):  
Social Justice ◽  
Reproductive Health ◽  
Rural Women ◽  
Armed Conflict ◽  
Sexual And Reproductive Health ◽  
Conflict Studies ◽  
Qualitative Synthesis ◽  
The Past ◽  
Analysis Process ◽  
Women's Role

Women have been the major victims of the Colombian armed conflict for more than 50 years. Nowadays, when the country faces an aftermath focused on reconciliation, understanding women’s experiences during the conflict is key to providing them tools for social justice and effective fulfilling of their needs. This qualitative synthesis of literature includes publications in Spanish and English of electronic databases over the past 20 years regarding rural women and the Colombian armed conflict. Studies were included for review if they were published between 2000 and 2019, were qualitative peer-reviewed articles, and addressed directly or indirectly the pregnancy process as well as the women’s sexual and reproductive health in rural Colombia. Seven of 169 articles initially identified were included for an inductive analysis of categories and themes. After the analysis process, three main themes emerged from the literature: (a) crumbling families, (b) being a woman: the challenges between being a peacemaker and a victim, and (c) protecting and caring of life. These three themes comprise 10 categories and 20 subcategories that provide support to the inductive qualitative synthesis. This review provides a comprehensive synthesis of the Colombian armed conflict focused on the victimization of women. It concludes with reflections about the Colombian women’s role in transitioning toward peace.

scholarly journals Novel AI driven approach to classify infant motor functions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Reich ◽  
Dajie Zhang ◽  
Tomas Kulvicius ◽  
Sven Bölte ◽  
Karin Nielsen-Saines ◽  
...  
Keyword(s):  
Learning Algorithm ◽  
Movement Pattern ◽  
Video Stream ◽  
Typically Developing ◽  
The Past ◽  
Movement Assessment ◽  
Computer Based ◽  
Ablation Study ◽  
First Time ◽  
Efficient Screening

AbstractThe past decade has evinced a boom of computer-based approaches to aid movement assessment in early infancy. Increasing interests have been dedicated to develop AI driven approaches to complement the classic Prechtl general movements assessment (GMA). This study proposes a novel machine learning algorithm to detect an age-specific movement pattern, the fidgety movements (FMs), in a prospectively collected sample of typically developing infants. Participants were recorded using a passive, single camera RGB video stream. The dataset of 2800 five-second snippets was annotated by two well-trained and experienced GMA assessors, with excellent inter- and intra-rater reliabilities. Using OpenPose, the infant full pose was recovered from the video stream in the form of a 25-points skeleton. This skeleton was used as input vector for a shallow multilayer neural network (SMNN). An ablation study was performed to justify the network’s architecture and hyperparameters. We show for the first time that the SMNN is sufficient to discriminate fidgety from non-fidgety movements in a sample of age-specific typical movements with a classification accuracy of 88%. The computer-based solutions will complement original GMA to consistently perform accurate and efficient screening and diagnosis that may become universally accessible in daily clinical practice in the future.

Crankshaft Stress Analysis—Combination of Finite Element and Classical Analysis Techniques

1990 ◽  
Vol 112 (3) ◽  
pp. 268-275 ◽  
Author(s):  
A. R. Heath ◽  
P. M. McNamara
Keyword(s):  
Stress Analysis ◽  
Concept Design ◽  
Low Friction ◽  
Failure Investigation ◽  
Engine Design ◽  
Computer Based ◽  
Analysis System ◽  
High Level ◽  
Engine Components ◽  
Oil Films

The conflicting legislative and customer pressures on engine design, for example, combining low friction and a high level of refinement, require sophisticated tools if competitive designs are to be realized. This is particularly true of crankshafts, probably the most analyzed of all engine components. This paper describes the hierarchy of methods used for crankshaft stress analysis with case studies. A computer-based analysis system is described that combines FE and classical methods to allow optimized designs to be produced efficiently. At the lowest level simplified classical techniques are integrated into the CAD-based design process. These methods give the rapid feedback necessary to perform concept design iterations. Various levels of FE analysis are available to carry out more detailed analyses of the crankshaft. The FE studies may feed information to or take information from the classical methods. At the highest level a method for including the load sharing effects of the flexible crankshaft within a flexible block interconnected by nonlinear oil films is described. This method includes the FE modeling of the complete crankshaft and the consideration of its stress field throughout an engine cycle. Fatigue assessment is performed to calculate the distribution of fatigue safety factor on the surface of the crankshaft. This level of analysis can be used for failure investigation, or detailed design optimization and verification. The method is compatible with those used for vibration and oil film analysis.

The evolution of computer-based analysis of high-resolution CT of the chest in patients with IPF

2021 ◽  
pp. 20200944
Author(s):  
Lucio Calandriello ◽  
Simon LF Walsh
Keyword(s):  
High Resolution ◽  
Computer Technology ◽  
Response To Treatment ◽  
Visual Interpretation ◽  
Future Directions ◽  
The Past ◽  
High Resolution Ct ◽  
Ct Analysis ◽  
Computer Based ◽  
Fibrotic Lung Disease

In patients with idiopathic pulmonary fibrosis (IPF), there is an urgent need of biomarkers which can predict disease behaviour or response to treatment. Most published studies report results based on continuous data which can be difficult to apply to individual patients in clinical practice. Having antifibrotic therapies makes it even more important that we can accurately diagnose and prognosticate in IPF patients. Advances in computer technology over the past decade have provided computer-based methods for objectively quantifying fibrotic lung disease on high-resolution CT of the chest with greater strength than visual CT analysis scores. These computer-based methods and, more recently, the arrival of deep learning-based image analysis might provide a response to these unsolved problems. The purpose of this commentary is to provide insights into the problems associated with visual interpretation of HRCT, describe of the current technologies used to provide quantification of disease on HRCT and prognostication in IPF patients, discuss challenges to the implementation of this technology and future directions.

Increased Efficiency of PEM Water Electrolyzers through Operating Temperature and Pressure Optimization

2021 ◽  
Vol MA2021-02 (41) ◽  
pp. 1263-1263
Author(s):  
Fabian Scheepers ◽  
Andrea Staehler ◽  
Markus Staehler ◽  
Edward Rauls ◽  
Martin Müller ◽  
...  
Keyword(s):  
Operating Temperature ◽  
Temperature And Pressure

Leak Testing

2021 ◽  
pp. 143-147
Author(s):  
Charles Becht
Keyword(s):  
Wall Thickness ◽  
Pipe Wall ◽  
Piping System ◽  
Pipe Wall Thickness ◽  
Pressure Testing ◽  
Leak Testing ◽  
Piping Systems ◽  
Design Pressure ◽  
Important Test

While the exercise of pressurizing a piping system and checking for leaks is sometimes called pressure testing, the Code refers to it as leak testing. The main purpose of the test is to demonstrate that the piping can confine fluid without leaking. When the piping is leak tested at pressures above the design pressure, the test also demonstrates that the piping is strong enough to withstand the pressure. For large bore piping where the pipe wall thickness is close to the minimum required by the Code, being strong enough to withstand the pressure is an important test. For small bore piping that typically has a significant amount of extra pipe wall thickness, being strong enough is not in question. Making sure that the piping is leak free is important for all piping systems.

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