Posts Tagged ‘PFDAVG’

Optimizing Safety Instrumented System Proof Testing

Posted in Safety on Monday, May 8th, 2017. No comments yet
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If you are new to the world of process safety, you quickly learn that it has its own jargon with phrases such as safety instrumented functions, proof test intervals, PDFavg, etc. A Flow Control magazine article, Ensuring safety compliance with optimized proof testing, written by Emerson’s Afton Coleman, Erik Mathiason and Tonya Wyatt does a […]

When is a Safety Integrity Level Rating of a Valve Required?

Posted in Final Control Element, Safety on Tuesday, November 3rd, 2015. No comments yet
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Control valves play a large role in process control. Emerson’s Riyaz Ali shared with me that he is often asked about their use in safety instrumented functions (also known as safety loops). When asked recently, he shared an ISA Safety Division newsletter from the fall of 2007. Unfortunately, I couldn’t find the newsletter in my […]

10 Ways to Improve Functional Safety

Posted in Safety on Wednesday, November 13th, 2013. One comment so far
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ISA Portugal recently hosted a conference on functional safety. Emerson’s Russell Cockman, whom you may recall from earlier safety-related posts, presented 10 ways to improve functional safety without worrying where to put the decimal point in the calculation. From his title, you might anticipate that Russell would bring his humor to the serious subject of […]

Separate Versus Integral Final Element Accessories in Safety Applications

Posted in Final Control Element, Safety on Monday, October 21st, 2013. 10 comments so far
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Final elements such as safety shutdown valves, emergency isolation valves, blowdown valves, etc., in safety instrumented functions (SIFs) are equipped with various accessories such as digital valve controllers, solenoid valves (SOV), and volume boosters, to name a few. Emerson’s Riyaz Ali shared a draft of a paper he is developing about the different approaches with […]

Safety Valve and Actuator Proof Test Coverage

Posted in Final Control Element, Safety on Wednesday, November 9th, 2011. 10 comments so far
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I saw an email string with a question asking if it’s possible to detect all possible failure modes in a safety valve if very intensive and intrusive tests, such as full-stroke testing, leak testing, etc. are performed. Would it be conceivable to use 100% proof test coverage when performing full repair upon detection of a […]