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Entries tagged with: Safety Instrumented Function

Close Enough? Not so Much
  • by Denise Chastain Knight, P.E., CFSE, CCPSC
  • Wednesday, May 27, 2015
  • Functional Safety

Close Enough? Not so Much

Performing a SIL Verification calculation on preliminary design information can be a very useful tool to dial in the Safety Instrumented Function (SIF), Safety Requirements Specification (SRS) content , and define critical elements for the field component purchase specifications. Conceptual verification is typically performed quickly with general design information.…

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PRODUCT SPOTLIGHT: Practical SIL Target Selection - Risk Analysis per the IEC 61511 Safety Lifecycle

Ten Years Later
  • by Steve Gandy, CFSP
  • Wednesday, February 19, 2014
  • Certification

Ten Years Later

It’s hard to believe that the IEC61511 standard has been in existence since 2003, and most companies operating in the process, chemical, and refining industries (or any other hazardous process manufacturer) have adopted its practices.  It’s also significant that any plants that were built back then with a…

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The Architectural Constraint Blind Side
  • by Denise Chastain Knight, P.E., CFSE, CCPSC
  • Thursday, August 27, 2015
  • Certification

The Architectural Constraint Blind Side

I did my homework, purchased certified devices, and specified physical redundancy. I expected an uneventful SIL Verification but the assessor is telling me that I have functions failing Architectural Constraints in the sensor and final element groups. How can that be? 

Low demand mode Safety Instrumented Function (SIF)…

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What’s Your Biggest Fear?
  • by John Yozallinas, CFSE
  • Friday, September 11, 2015
  • Certification

What’s Your Biggest Fear?

Plane crash?

Earthquake?

Ebola outbreak?

Shark attack?

There are probably lots more things to add to that list.  What could we do to prevent them?  Not too much for some… a little more for others.  But would those mitigations be practical?  What tolerable risk can we accept for these…

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Where Do You Stand with Functional Safety?
  • by Loren Stewart, CFSE
  • Thursday, February 21, 2019

Where Do You Stand with Functional Safety?

This year, make your New Year’s resolution safety! 

Take a moment this year and think about where you currently stand with functional safety. And actually, be honest with yourself. REALLY honest. Do you proof test on time, or does it sometimes get pushed out? Do you pull your devices…

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