safety integrity level study


Thread Starter


If any one has performed the SIL verification, I have following queries as below.

1. Since the SIL report is based on the SIF narratives, all the SIFs mentioned in the SIF narrative should be a part of the SIL report.

2. How does one specify the SIL level of any SIF configuration(sensor + logic solver + Final element) without even performing the SIL verification. Is the same performed using route 1H and 2H methods of IEC-61508.

Thanks in advance !!

Vishwanathan Gurumoorthy

You are very much right that the SIL verification has to follow SIL Assessment after Hazop study at Engineering stage. Based on SIL requirement as per scenario for an SIF, the Instrument&Control group designs the architecture for the SIF. The SIL validation has to be performed subsequently to confirm that the System PFD av. meets the SIL requirement. 2H route being the latest as per IEC-61508. this may be followed during operation stage, but it has nothing to do with the Assessment and verification steps in Engineering stage.