2010 Edition of B31.3 Process Piping Code: New Allowables for Appendix P—Alternative Stress Range Rules

2011 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Fatigue Failure ◽  
Stress Range ◽  
Singular Stress ◽  
Alternative Method ◽  
Text Base ◽  
Process Piping ◽  
Piping Systems ◽  
Operating Stress ◽  
Base Text

Appendix P Alternative Rules for Stress Range Evaluation was first introduced into the 2004 edition of ASME B31.3 Process Piping Code [1] as an alternative method that was conceived to be more computer friendly and possibly a more nearly theoretically defensible method of protecting piping systems individually against fatigue failure and dimensional ratchet than the singular stress range requirements of the Code’s base text (“base Code”). This paper describes the progression of events that led up to the inception of the Appendix and the subsequent revisions to same and detailing the reason for the 2010’s newly coined Allowable Operating Stress to protect against dimensional ratchet and Allowable Operating Stress Range to protect against fatigue failure.

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.

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.

Critical Analysis of the New High Cycle Fatigue Assessment Procedure From ASME B31.3—Appendix W

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Nikola Jaćimović ◽  
Sondre Luca Helgesen
Keyword(s):  
High Cycle Fatigue ◽  
Design Procedure ◽  
Piping System ◽  
Assessment Procedure ◽  
Stress Range ◽  
Cycle Fatigue ◽  
Fatigue Design ◽  
Process Piping ◽  
Piping Systems ◽  
Fatigue Evaluation

Abstract ASME B31.3, the leading process piping system design code, has included in its 2018 edition a new procedure for evaluation of high cycle fatigue in process piping systems. As stated in the Appendix W of ASME B31.3-2018, this new procedure is applicable to any load resulting in the stress range in excess of 20.7 MPa (3.0 ksi) and with the total number of cycles exceeding 100,000. However, this new procedure is based on the stress range calculation typical to ASME B31 codes which underestimates the realistic expansion stress range by a factor of ∼2. While the allowable stress range used typically for fatigue evaluation of piping systems is adjusted to take into consideration this fact, the new fatigue design curves seem not to take it into account. Moreover, the applicability of the new design procedure (i.e., welded joint fatigue design curves) to the components which tend to fail away from the bends is questionable. Two examples are presented at the end of the paper in order to substantiate the indicated inconsistencies in the verification philosophy.

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.

New Piping Flexibility Rules in ASME B31.3, Appendix P

2005 ◽  
Vol 128 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Charles Becht ◽  
David W. Diehl
Keyword(s):  
Stress Range ◽  
Flexibility Analysis ◽  
Process Piping ◽  
The Difference ◽  
Stress States ◽  
Stress Analyses

Alternative rules for performing flexibility analysis were added, as Appendix P, in ASME B31.3, the Process Piping Code, 2004 edition. These rules are considered to be more comprehensive than before; they were designed around computer flexibility analysis. To determine stress range, the difference in stress states, considering all loads, is computed. This paper describes the new rules, their intent, and provides several example piping stress analyses, comparing the results of an analysis using the Appendix P rules with that using the rules in the base Code.

Statistical Considerations for Determining Extent of Piping Inspections for RBI or API-570 Driven Inspections

2002 ◽  
Author(s):  
D. Hobbs ◽  
A. P.-D. Ku
Keyword(s):  
Random Field ◽  
Confidence Level ◽  
Confidence Limits ◽  
Damage State ◽  
Statistical Tools ◽  
Process Piping ◽  
Piping Systems ◽  
Inspection Data ◽  
Engineering Practices

This paper outlines a method for calculating the number of inspection locations for process piping inspections. The method determines the number of piping inspection locations required for an inspection to detect a particular damage state within the confidence limits of the premised inspection’s reliability. It is intended to be used for piping inspections per API-570, “Piping Inspection Code” and in the application of risk-based inspection concepts presented in AP1-581, “Risk Based Inspection, Base Resource Document”. This method combines recognized inspection and piping engineering practices and random-field statistical tools to calculate the number of inspection locations in piping systems with probabilistic confidence level. This method has provisions for future applications when inspection data is known, or there is greater uncertainty in the distribution of the degradation or the reliability of the inspection data is different than those premised in this paper.

2010 Edition of B31.3 Process Piping Code: A First Equation for Stress Due to Sustained Loads

2010 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Operating Temperature ◽  
Allowable Stress ◽  
Stress Range ◽  
Explicit Equation ◽  
Process Piping ◽  
Sustained Loads ◽  
History Of ◽  
First Time

For the first time in the history of the ASA [1], ANSI/ASME, ASME/ANSI, to the 2008 edition of ASME B31.3 Process Piping Code (hereafter referred to as “the Code”) [2], an equation for the Stress Due To Sustained Loads, SL, has been introduced into the Code. From its inception to the current edition, the Code has remained ambiguous in several areas. Even though the displacement stress range, SE, has been explicitly defined by both text and equation, the stress due to sustained loads, SL, is mentioned not with an explicit equation but with a statement that SL shall be limited by the allowable stress at the corresponding operating temperature, Sh. This paper describes the equation in detail and the background, the events, and the effort involved that led to the insertion of this equation into the Code.

The Biomechanical Relevance of Stress Range and Mean Stress in the Analysis of Variable Loading on Musculoskeletal Tissues

2016 ◽  
Vol 60 (1) ◽  
pp. 987-991
Author(s):  
Sean Gallagher ◽  
Mark Schall
Keyword(s):  
Fatigue Failure ◽  
Mean Stress ◽  
Stress Range ◽  
Variable Loading ◽  
Musculoskeletal Tissues ◽  
Occupational Tasks ◽  
Damage Accrual ◽  
Occupational Work ◽  
The Mean ◽  
Stress Variability

Musculoskeletal tissues usually experience loading referred to in the fatigue failure literature as “repeated stress” or “fluctuating stress” during the performance of occupational tasks. In addition, loads experienced during occupational work often involve highly stress variability. Under these types of loading conditions, the development of cumulative damage is highly influenced by the stress range and the mean stress associated with the loading regimen. This paper describes fatigue failure analysis techniques associated with variable loading situations, including cycle counting techniques, Goodman and Gerber equations for estimation of fatigue life, and the relevance of stress range and mean stress on damage accrual.

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