API-580 Equipment-Specific RBI Applications

Question 1

What unique inspection challenges do heat exchangers present in an RBI program?

Accepted Answer

Multiple damage mechanisms on tube and shell sides due to different process fluids

Answer

Heat exchangers face different damage mechanisms on the tube side versus the shell side due to exposure to different fluids, temperatures, and flow conditions, requiring inspection strategies tailored to each side.

Question 2

How should atmospheric storage tanks be addressed in an RBI program?

Accepted Answer

By evaluating both internal corrosion of the floor/shell and external corrosion of the bottom

Answer

Storage tanks require evaluation of internal corrosion (floor and lower shell from product side), external corrosion (tank bottom from soil side), and structural integrity of the roof and shell, per API 653 standards.

Question 3

What is the primary concern for piping systems in an RBI assessment?

Accepted Answer

Localized corrosion and erosion at flow changes, welds, and dead legs

Answer

Piping is particularly susceptible to localized damage at elbows, tees, reducers, welds, dead legs, and injection points where flow changes, turbulence, or stagnant conditions accelerate corrosion and erosion.

Question 4

Why do pressure relief devices (PRDs) need RBI evaluation?

Accepted Answer

Their failure to operate when needed can lead to catastrophic overpressure events

Answer

PRDs are the last line of defense against overpressure. If they fail to open when needed (fail to danger), catastrophic vessel rupture can occur, making their reliability critical to overall plant safety.

Question 5

How does insulation affect the RBI assessment of piping and equipment?

Accepted Answer

Insulation can trap moisture and hide corrosion under insulation (CUI)

Answer

Corrosion under insulation (CUI) is a significant damage mechanism where moisture trapped beneath insulation accelerates external corrosion, particularly in carbon steel operating between 10°F and 350°F (-12°C to 175°C).

API-580 Exam Practice Test

API-580 Exam Practice Test

API-580 Equipment-Specific RBI Applications