Full Content is available to subscribers

Subscribe/Learn More  >

Safety Loops Identification and Targeting Method Compliant With IEC61511 Requirements

[+] Author Affiliations
Philippe Cozzarin, Robert Brooks, Bret Dalton, Eric Kaufman, Kenneth Leary

GE Energy

Paper No. GT2007-27939, pp. 571-581; 11 pages
  • ASME Turbo Expo 2007: Power for Land, Sea, and Air
  • Volume 3: Turbo Expo 2007
  • Montreal, Canada, May 14–17, 2007
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 0-7918-4792-6 | eISBN: 0-7918-3796-3
  • Copyright © 2007 by ASME


Safety Instrumented Systems are used in gas turbine (GT) systems design to mitigate potential hazardous situations that can arise from process deviations. International standard IEC61511, (released in 2003) sets out an approach for establishing the relative safety integrity of a safety-instrumented system to perform its prescribed action over the product life cycle (design, installation, and operation of safety instrumented systems). This unified approach is currently being adopted as an industry standard (e.g. UK HSE Guidance Note PM84 and ISO DIS 21789 dedicated to Gas Turbine Safety). Using this approach, each Safety Instrumented Function (SIF) must be evaluated to determine the level of risk reduction required for safe operation of the plant. Properly targeting the necessary level of risk reduction is critical. Underestimating the target risk reduction level can result in exceeding the plant tolerable risk threshold. Over-estimating the target risk reduction level can result in increased life cycle cost of the system design. This paper describes a scientific-numeric approach for targeting the safety integrity requirements that comply with IEC 61511. An Accident Scenario Review (ASR) for each major hazard identified is used to identify the SIF and associated maximum probability of failure on demand (for demand mode) or maximum probability of dangerous failure per hour (for continuous mode). This method can be used for systems previously designed or in operation. The process integrates field experience to validate and justify model assumptions.

Copyright © 2007 by ASME
Topics: Safety



Interactive Graphics


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

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