Functional Safety 2016

DEFINITIONS

Process Safety Time - PST

• the time period between a failure occurring in the process or the

basic process control system (with the potential to give rise to a

hazardous event) and the occurrence of the hazardous event if

the SIF is not performed.

Safety Instrumented Function Response Time -

SIFRT

• the time taken for the SIF to detect the abnormal condition and

respond to bring the process to a safe state and prevent the

hazard from occurring.

Slide 5

Challenges in Achieving Safety Instrumented Function Response Time for a Fast-Acting Process• K. Rampaul, A.

Barnwell & S. Sookhoo