SIS

Question 1

In which layer of LOPA would you find a PSV (Pressure Safety Valve)?

Answer 1

Layer 4

Question 2

Which layers of LOPA are considered the mitigation layers

Answer 2

Layer 4 to 6

Question 3

What is the MAJOR difference between a SIS and a SIF?

Answer 3

SIF initiates the action and the SIS carries out the SIF

Question 4

What is the major function of SIS?

Answer 4

Monitor the process and take action when BPCS fails to do so

Question 5

What layer of LOPA can you find the SIS?

Answer 5

Layer 3

Question 6

What is RRF and what does it refer to?

Answer 6

Risk Reduction Factor: inverse of PFD in years

Question 7

What is PFD and what does it refer to?

Answer 7

Probability of Failure on Demand: probability that the SIS system malfunctions and does not shut down the process

Question 8

What layers of LOPA are considered preventative?

Answer 8

Levels 1 to 3

Question 9

What is a dike and what layer of LOPA would you find this on?

Answer 9

A dike is a containment unit that can be found on layer 5

Question 10

What does SIS consist of?

Answer 10

1) Logic Solvers
2) FCE
3) Redundancy
4) Sensors