API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 31:

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

  A. Transition limit.
  B. Endurance limit.
  C. Hardening limit.
  D. Speed limit.
  B. Endurance limit.

• Question 32:

  With sulfuric acid corrosion, mix points with _______ cause heat to be released and high corrosion rates can occur where the acid becomes diluted.

  A. Water
  B. Hydrogen
  C. H睸
  D. Caustic
  A. Water

• Question 33:

  Boiler water condensate corrosion is caused primarily by:

  A. Sodium sulfites or hydrazines
  B. Carbon dioxide and oxygen
  C. High pH from water treatment problems
  D. Dissolved iron oxides
  B. Carbon dioxide and oxygen

  ---

  According to API RP 571, in the section on Boiler Water Condensate Corrosion:

  "The major contributors to condensate corrosion are dissolved CO# and O#. Carbon dioxide forms carbonic

  acid in the presence of water, lowering pH and causing generalized corrosion."

  "Oxygen causes pitting and localized corrosion unless chemically treated."

  Thus, option B (Carbon dioxide and oxygen) is the primary root cause and the correct answer.

• Question 34:

  Which of the following generally manifests itself as a subsurface damage mechanism?

  A. Sulfide Stress Corrosion Cracking (SCC)
  B. Amine Stress Corrosion Cracking
  C. Caustic Cracking
  D. Stress-Oriented Hydrogen-Induced Cracking (SOHIC)
  D. Stress-Oriented Hydrogen-Induced Cracking (SOHIC)

  ---

  As defined in API RP 571, under Hydrogen Blistering and HIC/SOHIC:

  "SOHIC typically manifests as subsurface stepwise cracking, generally oriented perpendicular to the direction

  of stress."

  "This mechanism initiates below the surface, typically in weld heat-affected zones, and requires metallographic or advanced ultrasonic methods to detect."

  By contrast, SSC, caustic cracking, and amine SCC are primarily surface-initiated, stress-related cracking

  mechanisms.

  Thus, SOHIC is the subsurface mechanism in this list, making option D correct.

• Question 35:

  Annealed steels are more resistant to Spheroidization than normalized steels. _________ grained steels are more resistant than ______ grained steels.

  A. Fine, Course
  B. Course, Fine
  C. PWHT, Non-PWHT
  D. Non-PWHT, PWHT
  B. Course, Fine

• Question 36:

  Atmospheric corrosion is of greatest concern in:

  A. Dry climates in rural locations.
  B. Dry climates in industrial locations.
  C. Wet climates in rural locations.
  D. Wet climates in industrial locations.
  D. Wet climates in industrial locations.

• Question 37:

  A prime location for erosion is:

  A. In catalyst piping.
  B. Downstream of a gate valve.
  C. Any superheated steam piping.
  D. Upstream of a pump.
  A. In catalyst piping.

• Question 38:

  ________ injection downstream of the desalter is another common method used to reduce the amount of HCl going overhead.

  A. Hydrogen
  B. Nitrogen
  C. Water
  D. Caustic
  D. Caustic

• Question 39:

  Nitriding layers are magnetic. Therefore, _________ should be checked for magnetism as an initial screening for nitriding.

  A. 300 Series SS
  B. 400 Series SS
  C. Duplex SS
  D. Low alloy steel
  A. 300 Series SS

• Question 40:

  Refractory anchors must be resistant to __________ in high temperature services.

  A. Thermal fatigue
  B. Thermal cracking
  C. Stress cracking
  D. Oxidation
  D. Oxidation