The integrity requirements of the SIS have implications on all the elements that comprise the system such as sensors, interfaces, controllers, logic solvers, actuators and valves. While Safety Instrumented Systems design is for competent practitioners, this paper shows a straightforward approach to selecting the most suitable devices and performing the analysis to demonstrate the achievement of the required safety integrity level. Topics covered include:
- Overpressure protection system
- Factors leading to the choice of a logic server
- The safety integrity level
- Example failure data and methodology
