API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 331:

  Creep damage is found in high temperature equipment operating above the ________. Fired heater tubes and components, Catalytic reactors, FCC reactors and FCC fractionator and regenerator internals all operate in or near this.

  A. Transition range
  B. MADT
  C. Creep range
  D. None of the above
  C. Creep range

• Question 332:

  Hydrogen permeation or diffusion rates associated with wet H#S damage of carbon steel and low-alloy steels have been found to be minimal at a pH of:

  A. 3
  B. 5
  C. 7
  D. 9
  D. 9

  ---

  API RP 571 discusses this under Wet H#S Damage - Hydrogen Blistering, HIC, SOHIC:

  "Hydrogen generation is reduced as pH increases. At pH 9 and above, the corrosion potential is less favorable

  for hydrogen charging and thus permeation into the steel is minimal."

  "Most wet H#S cracking damage mechanisms are accelerated under acidic conditions (pH < 7)."

  Hence, high pH (around 9) environments offer the most protection against hydrogen damage, making option D the correct choice.

• Question 333:

  Since all fuels contain some amount of sulfur, sulfuric and sulfurous acid __________ can occur if the metal temperature is below this temperature.

  A. Corrosion
  B. Pitting
  C. Dew point corrosion
  D. All of the above
  C. Dew point corrosion

• Question 334:

  The amplitude and frequency of vibration as well as the _________ of the components are critical factors in vibration-induced fatigue.

  A. Velocity
  B. Temperature
  C. Fatigue resistance
  D. Material properties
  C. Fatigue resistance

• Question 335:

  The presence of ________ in H睸 streams increases the severity of high temperature sulfide corrosion at temperatures above about 500?F

  A. Amine
  B. Hydrogen
  C. Sulfides
  D. All of the above
  B. Hydrogen

• Question 336:

  Carbonate stress corrosion cracking and alkaline stress corrosion cracking are:

  A. Not preventable by post-fabrication stress relieving of weldments.
  B. Closely related corrosion mechanisms.
  C. Mechanisms that affect carbon steels and austenitic stainless steels.
  D. Different only in the level of alkalinity needed to initiate attack.
  B. Closely related corrosion mechanisms.

  ---

  In API RP 571, Carbonate SCC and Alkaline SCC are both discussed under mechanisms that occur in basic (high pH) environments, often with similar contributing conditions and prevention methods. The document highlights:

  "Carbonate SCC is considered a subcategory of alkaline stress corrosion cracking. It results from the concentration of alkaline carbonates under thermal insulation or deposits."

  "Both mechanisms involve the same key parameters: elevated temperatures, tensile stress, and high pH solutions."

  API RP 571, 3rd Edition, Section 4.2.2.4 and 4.2.2.3)

  Because these mechanisms share similar material susceptibility and operating conditions, they are indeed closely related--option B is therefore the accurate and supported answer.

• Question 337:

  Creep and stress rupture is more likely in a _________ grained material than a _______ grained material.

  A. Course, Fine
  B. Fine, Course
  C. Austenetic, Martensitic
  D. None of the above
  A. Course, Fine

• Question 338:

  How can temper embrittlement be prevented if a material contains critical levels of the appropriate impurity elements and is exposed in the embrittling temperature range?

  A. Use of a controlled pressurization sequence
  B. Postweld heat treatment (PWHT) of repairs
  C. Specification of Charpy V-notch impact test
  D. Embrittlement cannot be prevented
  C. Specification of Charpy V-notch impact test

  ---

  API RP 571 provides the following guidance regarding temper embrittlement:

  "For materials that contain impurity levels which make them susceptible to temper embrittlement, the most effective preventive measure is to specify low FATT or Charpy impact energy requirements."

  "These requirements ensure the material retains adequate toughness even if embrittlement occurs."

  "While temper embrittlement itself cannot always be fully prevented during long-term exposure to temperatures between 650癋 and 1070癋 (343癈-577癈), its effects can be identified and mitigated through impact testing criteria."

  Therefore, option C is correct. Specification of Charpy V-notch testing ensures material selection accounts for embrittlement susceptibility and maintains service integrity.

• Question 339:

  SSC is a form of ________ stress corrosion cracking.

  A. Hydrogen
  B. Caustic
  C. Polythionic
  D. Alkaline
  A. Hydrogen

• Question 340:

  Which of the following is related to all wet H#S damage mechanisms?

  A. pH of
  B. Localized zones of weld HAZ hardness above 200 HB
  C. Water vapor in the hydrocarbon phase
  D. Absorption and permeation of hydrogen
  D. Absorption and permeation of hydrogen

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  API RP 571, in its discussion on Wet H#S Damage, including HIC, SOHIC, and SSC, consistently identifies a

  shared mechanism:

  "All wet H#S-related damage mechanisms involve the absorption of atomic hydrogen, formed at the steel

  surface by the corrosion reaction in the presence of H#S."

  "The absorbed hydrogen may diffuse into the steel, accumulate at trap sites, and cause cracking or blistering."

  API RP 571, Section 4.2.2.7 - Wet H#S Damage Mechanisms)

  Thus, hydrogen absorption and permeation is a unifying mechanism across all these damage modes.