0

Full Content is available to subscribers

Subscribe/Learn More  >

Fitness for Service Assessment of Circumferential Cracks at Pipe Penetrations

[+] Author Affiliations
Fred V. Ellis

Tordonato Energy Consultants, Inc., Chattanooga, TN

Paper No. PVP2005-71050, pp. 403-410; 8 pages
doi:10.1115/PVP2005-71050
From:
  • ASME 2005 Pressure Vessels and Piping Conference
  • Volume 6: Materials and Fabrication
  • Denver, Colorado, USA, July 17–21, 2005
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 0-7918-4191-X | eISBN: 0-7918-3763-7
  • Copyright © 2005 by ASME

abstract

An engineering study of the main steam line pressure tap cracking was performed. The failure mechanism was thermal fatigue and the circumferential cracks initiate at the pipe penetration on the inside surface of the pipe. Based on the results, a parametric fitness for service study was performed to develop a flaw tolerance graph to be used for the evaluation and disposition of detected defects. The parameters are pipe diameter, penetration diameter, and inspection interval. The objective is to determine the value of the current crack size when weld repair is needed. The fatigue crack growth calculations used the NASGRO computer program. The crack geometries were a single corner crack from a hole in a plate and a corner crack from a hole in a plate with two cracks. The analysis used the properties for Grade 22 plate material given in the program and applied a correction factor (69 cycles for Grade 22 at room temperature equals 1 fatigue cycle with hold time of 12 hours for P11) to account for the pipe material of P11, 1-1/4Cr-1/2Mo and the nominal operating temperature of 482°C. There were approximately 40 cold starts and 210 hot starts per year for the unit. The magnitude of the remote stress depended on the temperature range for the hot and cold starts. The applied stress consisted of tension and bending stresses and was estimated by the observed failure life of approximately 20 years for the 3/4 penetration in the pipe size 18 pipe.

Copyright © 2005 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In