818-819 / 1145
RECOMMENDATIONS
• Clarity in industry functional safety standards
• Consider SIFRT through safety lifecycle
Guidelines
• Perform for all SIFs
• Preliminary evaluation before HAZOP/LOPA
• Early identification of fast acting SIFs
• Use existing plant data
Determining the
PST
• Established and documented early in design
• Re-evaluated throughout design – uncertainties,
installation, additional scenarios
Relationship
between PST and
SIFRT
Slide 22
Challenges in Achieving Safety Instrumented Function Response Time for a Fast-Acting Process• K. Rampaul, A.
Barnwell & S. Sookhoo