Guide for Planar Flaw Height Sizing by Ultrasonics

2013 ◽  
Author(s):  
Keyword(s):  
Planar Flaw

Recent Applications of ASME Code Case N-513 for Evaluation of Nonplanar Leaking Flaws

2008 ◽  
Author(s):  
Robert O. McGill ◽  
Kari L. Den Herder ◽  
Daniel B. Patten ◽  
Steven P. Queen
Keyword(s):  
Evaluation Criteria ◽  
Nuclear Industry ◽  
Energy Class ◽  
Operating Cycle ◽  
Evaluation Procedures ◽  
Asme Code ◽  
Moderate Energy ◽  
Planar Flaw

ASME Code Case N-513, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping, provides evaluation rules for the temporary acceptance of flaws, including through-wall flaws, in moderate energy Class 2 or 3 piping without performing repair/replacement activities. The Code Case has gone through three revisions with the latest approved by ASME Section XI being N-513-2. The Code Case allows for evaluation of both planar and nonplanar flaws. The planar flaw evaluation uses the rules in Appendix C of ASME Section XI. The nonplanar flaw evaluation uses the procedure provided in Code Case N-480. This Code Case has been used widely in the nuclear industry ever since it was published. Its use is expected to grow with plant aging and especially since Revision 2 was recently endorsed by the NRC in Regulatory Guide 1.147 without condition. The paper describes three specific applications of the Code Case to accept leaking flaws in piping components for continued operation till the end of the operating cycle when repairs could be performed. The use of this Code Case thus avoided costly and unnecessary shutdown of the plants in these cases. The evaluation procedures using this Code Case for these instances are described in the paper.

scholarly journals Proposal of Limit Moment Equation Applicable to Planar/Non-Planar Flaw in Wall Thinned Pipes Under Bending

2011 ◽  
Author(s):  
Masataka Tsuji ◽  
Toshiyuki Meshii
Keyword(s):  
Experimental Observation ◽  
Fracture Mode ◽  
Bending Moment ◽  
Moment Equation ◽  
Planar Flaw

In this paper, limit bending moment equation applicable to all types of planar and non-planar flaw in wall thinned straight pipes under bending was proposed. An idea to rationally classify planar/non-planar flaw in wall thinned pipes was proposed, based on the experimental observation focused on the fracture mode. The results point out the importance to distinguish axially and circumferentially long flaws in wall thinned pipes.

Proposal of a Guideline to Classify Planar/Non-Planar Flaw in Wall Thinned Straight Pipes Under Bending Load

2011 ◽  
Author(s):  
Toshiyuki Meshii
Keyword(s):  
Aspect Ratio ◽  
Fracture Mode ◽  
Planar Configuration ◽  
Bending Load ◽  
Planar Flaw

In this paper, an idea to rationally classify planar/non-planar flaw in wall thinned straight pipes under bending load was proposed, based on the fracture mode (cracking/non-cracking) observed in experiments. This cracking phenomenon was correlated with the aspect ratio of the flaw planar configuration. Finally, a guideline to classify this planar/ non-planar flaw based on flaw aspect ratio was proposed.

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