0

Full Content is available to subscribers

Subscribe/Learn More  >

Assessment of the Reliability Level Embedded in Pipeline Design Codes

[+] Author Affiliations
Sviatoslav Timashev

Science and Engineering Center “Reliability and Safety of Large Systems and Machines”, Yekaterinburg, RussiaUral State Agrarian University, Yekaterinburg, RussiaUral Federal University, Yekaterinburg, Russia

Anna Bushinskaya

Science and Engineering Center “Reliability and Safety of Large Systems and Machines”, Yekaterinburg, RussiaUral State Agrarian University, Yekaterinburg, Russia

Paper No. IPC2014-33151, pp. V003T12A008; 11 pages
doi:10.1115/IPC2014-33151
From:
  • 2014 10th International Pipeline Conference
  • Volume 3: Materials and Joining; Risk and Reliability
  • Calgary, Alberta, Canada, September 29–October 3, 2014
  • Conference Sponsors: Pipeline Division
  • ISBN: 978-0-7918-4612-4
  • Copyright © 2014 by ASME

abstract

Recently a long time discussion among specialists about the meaning of the probabilities of failure (POF) produced by different reliability analysis methods surfaced in pipeline journals. This paper, which was a long time in the making, is a follow-up on the discussion and analyses the actual reliability level which was empirically embedded in codes for pipeline design [B31G, B31Gmod, Shell92 and Battelle (PCORRC)] and Building Standard (BR) Main Pipelines #2.05.06-85, using a real pipeline as an example.

Assessment of the actual reliability level empirically embedded in BR is based on assessing the order of the quintiles of strength parameters (design values of tensile strength and yield strength of the pipe material) and load (internal pressure) on the pipeline.

This approach allows direct connection of the deterministic safety coefficients used in the BR with the level of reliability of the pipelines associated with these coefficients.

The actual reliability level, empirically embedded in international codes, is calculated as the probability that the limit state function (LSF) of ideal pipeline (without defects) is positive. LSF = PfPop, where Pf is the failure pressure of an ideal pipe, which is estimated by any design code; Pop is the operating pressure. The failure and operating pressure are considered as random variables. The expression for this probability was obtained analytically and in closed form.

Recommendations are also presented for choosing probability distributions and statistical parameters for random variables RVs. Extensive calculations permitted revealing the reliability levels which are actually present in the analyzed international pipeline design codes. In a nutshell, the paper proves that the international codes under consideration are very reliable, as they produce very safe designs of pipelines with very low POF, and, hence, provide large safety coefficients, and that the algorithm developed in the paper permits connecting the current level of pipeline degradation (in terms of POF), with its current safety coefficient, which, in this case, is a function of time.

All calculating in the paper where performed using MathCAD. Illustrations of these calculations are also presented in the paper.

Copyright © 2014 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