Safeguarding of industrial process plants by means of process control engineering - Verification of the hardware safety integrity of safety instrumented systems
The methods described here are used to verify the requested Safety Integrity Level (SIL) of the hardware for the safety instrumented systems (SIS). On the one hand there is the validation of structural suitability on the other hand SIL qualification of a SIS is depending on its safety related probability of failure (PDF). The structural suitability as well as the PFD and the general procedure for determining of the PFD inclusive helpful formulas are described. Procuring of the relevant reliability characteristics of devices and typical structures for SIS are given. Hardware safety integrity for example structures give additional support to the user.