The world of functional safety has its own tribal language and acronyms, e.g. safety instrumented systems (SISs), safety instrumented functions (SIFs), logic solvers, final elements (FEs), safety integrity level (SIL), probability of failure on demand (PFD), etc. In a Hydrocarbon Engineering article, Keep in the Safety Loop, Emerson’s Riyaz Ali does an excellent job of […]
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 […]
A few months ago, I attempted to clear up some misconceptions about the use of digital valve controllers in safety applications in a post, Clarifications on the Use of the DVC6000 SIS in Safety Applications. It addressed misconceptions about references to the obsolete DIN 19250 standard, failsafe DVC 6000 SIS, SIL 3 suitability not being […]
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 […]
Exida’s Dr. William Goble and Emerson’s Afton Coleman presented Addressing Partial Stroke Testing Fears – Avoiding False Trips / Risk Through… Their abstract: It is not uncommon for some users to perform partial stroke testing (PST) using cumbersome mechanical or pneumatic devices, or avoid PST altogether due to fears of spurious trip. This workshop addresses […]
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