Safety Integrity Level 2 (SIL2)

Hi ,

First SIL Has to defined By Risk graph analysis/Other Method depending upon the process hazard (Frequency, Consequence, Possibility of avoiding accidents ,Proability of avoiding accident ,Etc),

Depending upon your mode(Lowdemand /High Demand mode) use the proper equation defined in IEC 61508 Part 05

SIL 2 defines that your entire ESD loop containing,

1) Sensor (EG Pressure Transmitter )

2) logic solver (PLC)

3) Final element ( Shutdown Valve )

Sum of Each of PFD Value should be in the range 10 race to -02 to -03 (For SIL 02 )

For Prelimanary estimate you can use IEC 61508 part 05/06.

For more Detailing you can get the MTBF value from OREDA 2002

I suggest you Purchace IEC 61508 /61511 Series For more Info

Hi,

It's good information. Refer to the theoretical as mentioned, should the unit certify SIL 2? Is it allowed to utilize the unit that not SIL 2 compliance? Can we endorse from NON to certified SIL 2? Let's say for the sensor (EG Pressure Transmitter).

Thanks,

Save the earth, please consider the environment before printing

Bear in mind that SIL certificates are of no value without a copy of the report on the system. It is the report that is of value, not the certificate.

Ideally : No,

Since The PFD value will Increase If your Not complying with SIL level 02( Non Certified Pressure Transmitter ) That in turn will Increase The PFD avg of the Entire ESD loop , which will Lower the SIL rating.

Also its very rare that if your using Non SIL 2 Complaint transmitter you will be able to achieve the required PFD value for a SIL 2 loop

Better To get Certified device from Third party Inspection like EXIDA , RISKOLOGY

Regards

Jose