api API-571 Exam Questions

Questions for the API-571 were updated on : Nov 21 ,2025

Page 1 out of 31. Viewing questions 1-15 out of 454

Question 1

What method is most used to assure boiler feed water corrosion is not occurring?

  • A. Spot UT readings at turbulent areas
  • B. Profile RT at turbulent areas
  • C. Profile RT at stagnant areas
  • D. Laboratory analysis of boiler feedwater
Answer:

D

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Question 2

What treatment is used to prevent boiler feed water corrosion?

  • A. Oxide scavengers are added to process
  • B. Oxygen scavengers are added to process
  • C. Sulfide scavengers are added to process
  • D. Sulfur scavengers are added to process
Answer:

B

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Question 3

Protection in a boiler from boiler feed water corrosion is accomplished by:

  • A. Injecting chlorines to kill microbiological bugs.
  • B. Injecting caustic to lower the ph to < 4.0.
  • C. Lowering solids content in boiler feed water to less than 50 ppm.
  • D. Maintaining a protective corrosion layer of magnetite (Fe3O4).
Answer:

D

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Question 4

Corrosion from oxygen in boiler feed water usually creates:

  • A. Uniform corrosion.
  • B. Isolated pitting.
  • C. Intergranular cracking.
  • D. Transgranular cracking.
  • E. Hard and brittle zones.
Answer:

B

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Question 5

Which of the following is not a major factor associated with boiler water condensate corrosion?

  • A. Operating pressure
  • B. Oxygen content
  • C. Carbon dioxide content
  • D. Process ph
  • E. Temperature
Answer:

A

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Question 6

Sulfidation usually creates:

  • A. Uniform corrosion.
  • B. Isolated pitting.
  • C. Intergranular cracking.
  • D. Transgranular cracking.
  • E. Hard and brittle zones.
  • F. Inspection nightmares.
Answer:

A

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Question 7

Sulfidation is primarily caused by:

  • A. Impacting particles.
  • B. Sulfur compounds decomposing at higher temperatures.
  • C. Sulfur compounds being created in the FCCU (Cat Cracking Unit).
  • D. Elemental sulfur collecting in stagnate areas, e.g. dead legs.
  • E. Operators failing to adequately control the ph of sulfur streams.
Answer:

B

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Question 8

Resistance to sulfidation increases as the:

  • A. Chromium content in the material increases.
  • B. Nickel content in the material increases.
  • C. Material’s tensile strength decreases.
  • D. Material’s tensile strength increases.
Answer:

A

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Question 9

Sulfidation of iron-based alloys usually begins at about:

  • A. 150 oF.
  • B. 250 oF.
  • C. 500 oF.
  • D. 1100 oF.
Answer:

C

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Question 10

Which of the following is not a major factor associated with corrosion by sulfidation?

  • A. Alloy composition
  • B. Operating pressure
  • C. Operating temperature
  • D. Sulfur content
Answer:

B

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Question 11

Mechanical fatigue can cause cracks that initiate from the surface and often form a:

  • A. Clam shell appearance.
  • B. Snail shell appearance.
  • C. Turtle shell appearance.
  • D. Shell Oil shell appearance.
  • E. Taco shell appearance.
Answer:

A

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Question 12

Inspecting for high-cycle fatigue can be difficult since:

  • A. The cracks are extremely tight.
  • B. Predicting the location of cracking is difficult.
  • C. Once the crack begins, only a few cycles are needed for the crack to lead to failure.
  • D. Often the equipment is vibrating making non-destructive evaluations difficult.
Answer:

C

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Question 13

The endurance limit is usually about:

  • A. 10-20% of a material’s ultimate tensile strength.
  • B. 40-50% of a material’s ultimate tensile strength
  • C. 10-20% of a material’s yield strength.
  • D. 40-50% of a material’s yield strength.
  • E. Half way up the ladder of a 150’ column (tower).
Answer:

B

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Question 14

Which material does not have an endurance limit?

  • A. Non-normalized carbon steel
  • B. Normalized carbon steel
  • C. Stainless steel
  • D. Titanium
Answer:

C

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Question 15

Fatigue will not occur in carbon steel if stresses are below the:

  • A. Transition limit.
  • B. Endurance limit.
  • C. Hardening limit.
  • D. Speed limit.
Answer:

B

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