3 replies to this topic

[seuenergy]

Dear all,

 

In NFPA 86, SIL rating requirements are mentioned. I am wondering whether the requirements are only for elements or for the whole loop.

[Pilesar]

The elements in the loop such as transmitters, PLC must be capable of SIL-2 rating. The whole loop should conform to the burner management system requirements of NFPA 86 which is not the same thing as a SIL-2 loop. For whatever reason, the loop requirements are different.

[seuenergy]

The elements in the loop such as transmitters, PLC must be capable of SIL-2 rating. The whole loop should conform to the burner management system requirements of NFPA 86 which is not the same thing as a SIL-2 loop. For whatever reason, the loop requirements are different.

Hi Pilesar,

 

Thanks for your reply. 

So the loop requirements should be determined by risk rank for specific scenario? 

[Pilesar]

Your furnace controls should be based on risk assessment. NFPA 86 provides a standard for guidance. Sometimes the requirements for a safety instrumented system are difficult to meet for furnaces. If your controls conform to NFPA 86, then that might not be enough to satisfy your risk. You can always choose to do more than a standard requires. Check with your insurance company to see if they have their own requirements or guidance documents.