API API-571 Online Practice Questions and Exam Preparation

API API-571 Online Questions & Answers

• Question 231:

  Both sulfide stress corrosion cracking and stress-oriented hydrogen-induced cracking are most often found in:

  A. Areas where there is significant hydrogen blistering.
  B. Steel weldments.
  C. Hardened steels.
  D. Areas with temperatures above 300癋 (149癈).
  C. Hardened steels.

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  API RP 571 explains that both Sulfide Stress Cracking (SSC) and SOHIC are:

  "Strongly influenced by material hardness. Carbon and low alloy steels with hardness exceeding 22 HRC (248 Brinell) are most susceptible."

  "They occur in hardened steels under tensile stress, in the presence of wet H#S environments."

  API RP 571, Sections 4.2.2.1 and 4.2.2.7 - SSC and SOHIC)

  Therefore, hardened steels are the common factor for both mechanisms, making option C the correct choice.

• Question 232:

  For exchangers where the cooling water chemistry is poorly maintained, what can be done to improve corrosion resistance?

  A. Lower the water velocity
  B. Increase the tube diameter
  C. Upgrade the metallurgy of the exchanger
  D. Increase the process side temperature above 212癋 (100癈)
  C. Upgrade the metallurgy of the exchanger

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  From API RP 571, under Cooling Water Corrosion:

  "If proper water treatment is not feasible or consistently maintained, upgrading the metallurgy of exchanger

  tubes to more corrosion-resistant materials such as stainless steel or titanium may be necessary."

  "This is especially important in seawater or brackish water cooling applications or in once-through systems."

  API RP 571, Section 4.3.1.1 - Cooling Water Corrosion)

  Thus, the most effective long-term solution in cases of uncontrolled water quality is to upgrade metallurgy, making option C correct.

• Question 233:

  Many thermal fatigue cracks are filled with:

  A. chlorides.
  B. hydroslime.
  C. oxides.
  D. sulfides.
  C. oxides.

• Question 234:

  The creep threshold temperature for 1 ? 2 ? 5 and 9 Cr is ________.

  A. 600?F
  B. 700?F
  C. 800?F
  D. 1000?F
  C. 800?F

• Question 235:

  Which of the following materials are susceptible to polythionic acid SCC?

  A. 300 Series SS
  B. Alloy 600
  C. Alloy 800
  D. All of the above
  D. All of the above

• Question 236:

  Vessels constructed after December, 1987 are subject to the requirements of ________ of ASME Section VIII, Division 1.

  A. UW-26
  B. UG-31
  C. UB-54
  D. UCS-66
  D. UCS-66

• Question 237:

  Stresses acting on the weldments are significantly ________ when austenitic stainless steel filler metal is used. A nickel based filler metal has a coefficient of thermal expansion closer to carbon steel resulting in significantly lower stress at elevated temperatures.

  A. Lower
  B. Higher
  C. Altered
  D. None of the above
  B. Higher

• Question 238:

  A hard, brittle surface layer will develop on some alloys due to exposure to high temperature process streams containing high levels of nitrogen compounds such as ammonia or cyanides, particularly under reducing conditions, is called _______.

  A. Carburization
  B. Spheroidization
  C. Nitriding
  D. None of the above
  C. Nitriding

• Question 239:

  General or localized corrosion of carbon steels and other metals caused by dissolved salts, gases, organic compounds or microbiological activities is called ________.

  A. Flue Gas Corrosion
  B. Atmospheric Corrosion
  C. Cooling Water Corrosion
  D. None of the Above
  E. All of the Above
  C. Cooling Water Corrosion

• Question 240:

  Caustic is sometimes added to process streams for ________ or as a reactant.

  A. Stability
  B. Corrosion control
  C. Neutralization
  D. Inhibiting
  C. Neutralization