Questions About SIL 3 System Requirements


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What are the requirements for SIL 3 system? My hardware and software is sil 3. Does it still require dual inputs and outputs to make it sil 3? Or with single input and output it is sil 3? kindly also refer some pdfs.

kindly explain sil 3 system requirements....
As a CSE I know put it, a lot of people try to "buy" SIL systems. It can't be done. The responsibility for SIL is the plant owner's, and they need their own certified safety engineer to help with the plant design and safety analysis. Having SIL rated components is nowhere near enough, and there is no document that explains how to achieve a SIL rating, because it is very system specific.

Also beware overdoing it on specifying SIL ratings, as there is literally a thousand-fold increase in statistical safety per level, which doesn't come cheap. A good CSE can help avoid that pitfall and probably pay for themselves.
Just because hardware (or software) is "suitable for use" in SIL3 does not automatically mean you have a SIL3 (or for that matter) any achieved SIL.

SIL applications have many requirements as to equipment selection , design of the safety function etc. I strongly recommend you get consulting or design services from someone who is trained / accredited in this area.

Several sources of training are available including ISA , exida and others.
1. SIL certification: a third-party assessment, verification and certification that evaluates and confirms the safety integrity level (SIL) or performance level (PL) of the security equipment.

2, SiL3 is a certification level in SIL certification.

Because, SIL certification is divided into four levels, namely SIL1, SIL2, SIL3 and SIL4, including two levels: product and system. SIL4 is the most demanding.
I think it is unfortunate that the "SIL" term is used for both components and the system; it leads to the confusion I noted above, that buying SIL components at a particular rating means you have a SIL system at that rating. Nothing could be further from the truth.

In fact, a lot of times you don't need SIL 3 components to make a SIL 3 system. Two SIL 2 valves in series, for example, can often achieve the reliability needed for a particular system and wind up far cheaper than a single SIL 3 valve. On the other hand, a SIL 3 valve by itself may <i>not</i> be safe enough and require another valve in series to make the <i>system</i> SIL 3. Its why you need an expert and the right software to analyze the system and optimize for both cost and safety.