SIL (design) verification
For every single SIL 1/2/3 or 4 safeguard, it should be verified that the safeguard is designed according to the standards IEC 61511 or IEC 61508, this is called SIL verification;
- Identification of safeguard. It is wise to make a schematic drawing with all the relevant sensors, components and final elements.
- Verifying the functionality of the safeguard.
- Determine whether the safeguard is independent (enough) from the control system.
- Check against the architectural requirements (e.g. is one valve sufficient?).
- Check to the probabilistic requirements (calculation of probability of failure on demand).
- Check for systematic faults.
It is highly recommended to make taylor-made test procedures during design phase.
Also for HIPPS systems (High-integrity pressure protection system) it is necessary to perform a SIL verification.