API-580 Risk Mitigation and Control Measures 2

Question 1

In API-580, which inspection effectiveness category provides the greatest risk reduction credit?

Accepted Answer

Highly effective

Answer

Ineffective

Answer

Poorly effective

Answer

Usually effective

Question 2

What happens to the calculated probability of failure (POF) in an RBI assessment as the number of highly effective inspections increases?

Accepted Answer

POF decreases due to the inspection confidence factor applied

Answer

POF increases because more inspections reveal more defects

Answer

POF remains unchanged since only process conditions affect it

Answer

POF is set to zero after three consecutive highly effective inspections

Question 3

Which API standard complements API-580 by providing fitness-for-service (FFS) assessment methodology that can be used as a mitigation input?

Accepted Answer

API-579/ASME FFS-1

Answer

API-510

Answer

API-571

Answer

API-650

Question 4

In API-580 RBI, what is the effect of implementing process changes (e.g., reducing H2S concentration) on the risk profile?

Accepted Answer

It can reduce the probability of failure by mitigating active damage mechanisms

Answer

It only affects the consequence of failure, not the probability

Answer

It increases risk because process changes introduce uncertainty

Answer

It has no effect unless the change eliminates all corrosive species

Question 5

What role do Safety Instrumented Systems (SIS) play in API-580 consequence of failure (COF) mitigation?

Accepted Answer

SIS reduce the consequence by automatically isolating or shutting down hazardous releases

Answer

SIS reduce the probability of failure by detecting corrosion

Answer

SIS have no formal role in the API-580 RBI framework

Answer

SIS are only applicable to rotating equipment, not static equipment

Question 6

According to API-580, when should a risk mitigation action plan be documented and tracked?

Accepted Answer

Whenever mitigation actions are identified as part of the RBI process

Answer

Only when equipment risk exceeds the highest risk category

Answer

Only at the end of the RBI study when all assessments are complete

Answer

Only when regulators formally request documentation of mitigation actions

Question 7

Which of the following metallurgical upgrades is considered a risk mitigation measure in an RBI program for equipment subject to stress corrosion cracking (SCC)?

Accepted Answer

Post-weld heat treatment (PWHT) to reduce residual stress

Answer

Switching to a lower-grade carbon steel to reduce cost

Answer

Increasing wall thickness without changing material specification

Answer

Applying a thin organic coating over existing welds