exida explains Blog

Look at the photo. What do you see? I see a ball valve with:

• a valve body
• a ball
• a stem that can turn the ball

What are the high level potential failures for a ball valve?

• Stem stuck, can no longer turn (dangerous)
…

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Look at the picture. What do you see? I see a spring return actuator with

• a diaphragm chamber
• a spring chamber
• the scotch-yoke mechanism

What are the high level potential failures for a ball valve?

• Scotch-yoke mechanism breaks, can no longer operate valve…

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Please see the first entry of the Requirements Management blog series here.

The concepts of allocation and derivation are sometimes misunderstood when it comes to requirements management.  This can lead to confusion and even to safety problems.  The process of derivation involves the writing of a new requirement, …

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ICS cybersecurity standards such as ISA 62443 (formerly ISA 99) and NERC CIP require operators to have policies and procedures in place to monitor and maintain their critical ICS cyber assets.  For anything other than very small systems, the obvious choice is to implement systems…

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IEC 61511: 2016 Process Industry Sector

IEC 61511 is a technical standard that sets out practices in the engineering of systems that ensure the safety of an industrial process through the use of instrumentation. It entails requirements for users of process control and instrumentation for component / element or sub-system safety.…

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Systematic Capability is achieved when the equipment used to implement any safety function achieves two goals: the design process has used procedures intended to prevent systematic design errors (fault avoidance) and the design has systematic design control mechanisms such as a diagnostic for incorrect software execution (fault control).  The rigor…

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The world of automation has changed significantly over the past 30 years.  I have fond memories of starting my career by calibrating, adjusting, and tuning pneumatic control loops while working my way through the electronic age right up to the present digital and cyber generation of automation.  If you…

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Thinking about developing a safety product?  Use these 3 steps as a starting point:

1. Know thyself

Do you have documented development processes that govern how you develop a product from start to finish?  If not, start by writing down what is actually being done.  Interview the people…

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Since the announcement of the 1st Annual exida Safety Awards program a few weeks ago I have received a few questions and a challenge.  The questions from manufacturers mainly focused on how to enter their product and what is the…

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There is usually a natural order to things. But there are times when the natural order gets disrupted, and this could be for any number of reasons:  we get busy, overloaded with tasks or information, tired, complacent, etc.  But when you think about it, most of the excuses we…

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2013 was a good year for functional safety progress.  exida Certification issued a record number of new product functional safety certifications in mostly every product category - valves, actuators, solenoid valves, PLCs, fire and gas sensors, process sensors, and components.  The component category is one of the most…

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Over the course of several blogs , I talked about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it takes…

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Industry Benchmark Survey on Alarms as Safeguards and Independent Protection Layers (IPLs)

exida recently conducted an industry benchmark survey on the practices for the use of alarms as safeguards and IPLs. With over 200 safety practitioners from around the world providing responses, you can use the survey findings to…

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How many development teams have heard those few, innocent words uttered from Marketing/Management toward the end of the development phase of a project, only to have their schedule blown out of the water?  The phase of development into which the change is introduced determines the size of the concentric…

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Formalize your process.

Companies often have a pretty good hardware development process in place, dealing with electrical and mechanical drawings, bills of material, and the factory floor interface.  Most of these processes are in place so the manufacturing department knows what to make and how to put it together. …

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Typically a person’s salary reflects the value of their skillset and the importance of their role to their company. If that’s TRUE, then there is some good news for safety practitioners. A recent salary survey conducted by ISA and published in InTech magazine benchmarked the average salary…

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IEC 61508 and IEC 61511 are known as “performance” based standards.  Specific design rules, as found in “prescriptive” standards, are not included, allowing for innovation and new technology, as well as creativity and advancement.  However, it does imply that a certain level of competency is required.

Others would strongly…

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I got an email saying that the exida's www.SILSafeData.com minimum failure rates were way too high.  The email went on to say that his REAL field failure data showed a result of 150 FITS for a remote actuated valve assembly.  The lowest SILSafeData limits for clean service, Class IV leakage,…

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Oh Really?

It must have been the week of the Proof Test Coverage (PTC) questions. In the latest marketing wars between vendors, the Proof Test Coverage has been used as a weapon. Who would have ever thought about using Proof Test Coverage to show that product A…

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