API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 1:

  Improved resistance to erosion is usually achieved through increasing substrate ________ using harder alloys, hard facing or face-hardening treatment.

  A. Composition
  B. Stress
  C. Hardness
  D. None of the above
  C. Hardness

• Question 2:

  Liquid metal embrittlement can occur if 300 Series SS comes in contact with molten _______.

  A. Copper
  B. Mercury
  C. Zinc
  D. Lead
  C. Zinc

• Question 3:

  (Hydrogen embrittlement of carbon steels is most likely to occur at temperatures of:)

  A. 850 癋 to 1000 癋 (454 癈 to 538 癈)
  B. 50 癋 to 200 癋 (10 癈 to 93 癈)
  C. 400 癋 to 500 癋 (204 癈 to 260 癈)
  D. 650 癋 to 850 癋 (343 癈 to 454 癈)
  B. 50 癋 to 200 癋 (10 癈 to 93 癈)

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  Comprehensive and Detailed From Exact Extract: According to, low-temperature damage

  API RP 571 hydrogen embrittlement (HE) of carbon steels is a mechanism. It occurs when atomic hydrogen enters the steel lattice, reducing ductility and toughness and potentially causing cracking or delayed failure.

  API RP 571 clearly differentiates HE from high-temperature hydrogen damage mechanisms (such as HTHA). Hydrogen embrittlement is most severe at ambient to moderately elevated temperatures, typically below about 200 癋 (93 癈), where hydrogen mobility and trapping promote embrittlement.

  At higher temperatures, hydrogen tends to diffuse out of the steel and embrittlement effects diminish.

  Referenced Documents (Study Basis): API RP 571 - Section on Hydrogen Embrittlement

• Question 4:

  In fired heater tubes, dissimilar weld metal cracking forms primarily on the _______ of the material.

  A. Outside
  B. Inside
  C. Welds
  D. All of the above
  A. Outside

• Question 5:

  Carbon dioxide (CO? corrosion results when CO?dissolves in water to form ________.

  A. Carbon monoxide
  B. Carbonic acid
  C. Hydrofluoric acid
  D. None of the above
  B. Carbonic acid

• Question 6:

  Vibration-induced fatigue can be eliminated or reduced through _________ and the use of supports and vibration dampening equipment. Material upgrades are not usually a solution.

  A. Hangers
  B. Dummy legs
  C. Design
  D. None of the above
  C. Design

• Question 7:

  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
  B. Operating pressure

• Question 8:

  What standard refers to Fitness-For-Service evaluations?

  A. RP 581
  B. RP 579
  C. RP 588
  D. RP 568
  B. RP 579

• Question 9:

  Corrosion under insulation mitigation is best achieved by:

  A. Using low-chloride insulation
  B. Maintaining process temperatures at the boiling point of water
  C. Implementing a carefully planned, periodic inspection program
  D. Using appropriate coatings
  D. Using appropriate coatings

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  According to API RP 571 and API RP 583:

  "The most effective mitigation of CUI is the use of appropriate coatings underneath the insulation, which

  are resistant to moisture and chloride ingress."

  "Inspection and insulation selection are also important but are secondary controls."

  API RP 571, Section 4.3.4 - Corrosion Under Insulation; API RP 583)

  Hence, option D is correct.

• Question 10:

  An NPS 3/4 (DN 20) carbon steel unsupported high-point vent on a steam line has failed by cracking. The most likely cause is:

  A. mechanical fatigue.
  B. thermal overload.
  C. sulfide stress cracking.
  D. original weld defect.
  A. mechanical fatigue.

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  According to API RP 571 Section 5.2.1 (Fatigue - High Cycle and Low Cycle) : "Unsupported small-bore attachments like vents and drains are prone to high-cycle mechanical fatigue due to

  vibration. These attachments experience cyclic stress, especially near welds or bends." Thermal overload is unlikely without over-temperature data. SSC (Option C) requires a wet H2S environment, which is not indicated. Weld defects may contribute but are less likely the root cause without other signs. Hence, mechanical fatigue (Option A) is most probable in this configuration.