Free API-571 pdf Files With Updated and Accurate Dumps Training
Top-Class API-571 Question Answers Study Guide
NEW QUESTION # 17
Cracks that are typically straight, non-branching, and devoid of any associated plastic deformation are likely associated with which type of failure?
- A. Stress corrosion cracking
- B. Brittle fracture
- C. Thermal fatigue
- D. Temper embrittlement
Answer: B
NEW QUESTION # 18
Sulfuric acid promotes general and localized corrosion of carbon steel. Carbon steel heat affected zones may experience severe corrosion. Acid concentration, temperature, alloy content and ____________ are critical factors affecting sulfuric acid corrosion.
- A. Ductility
- B. Stress
- C. Velocity
- D. Pressure
Answer: C
NEW QUESTION # 19
Corrosion from oxygen tends to be __________ type damage and can show up anywhere even if only very small amounts break through the scavenging system.
- A. Pitting
- B. Cracking
- C. Localized
- D. General
Answer: A
NEW QUESTION # 20
Cavitation is best prevented by avoiding conditions that allow the absolute pressure to fall below the ___________ of the liquid or by changing the material properties.
- A. Vapor pressure
- B. Maximum pressure
- C. Pressure/vapor ratio
- D. Minimum pressure
Answer: A
NEW QUESTION # 21
Severe internal grooving corrosion is found at the bottom of a 4-inch (101.6 mm) carbon steel piping system in steam condensate service. Which of the following is the most likely cause?
- A. Carbonate corrosion
- B. Erosion-corrosion
- C. Ammonium bisulfide corrosion
- D. Carbon dioxide corrosion
Answer: D
Explanation:
API RP 571 explains under Condensate Corrosion (CO# Corrosion):
"In condensate systems, carbon dioxide dissolves in the water forming carbonic acid, which leads to localized corrosion, including grooving and under-deposit attack, especially at low points like the bottom of horizontal piping."
"This is most commonly observed in steam condensate return lines, and the damage is localized due to stratification." This matches the scenario described, where internal grooving at the bottom of steam condensate piping is characteristic of CO#-induced corrosion. Hence, option A is correct.
NEW QUESTION # 22
High strength steels are susceptible to LME when they come in contact with molten ________.
- A. Both A and C
- B. Lead
- C. Cadmium
- D. Zinc
Answer: A
NEW QUESTION # 23
Primarily hot-wall piping and equipment in the following units can be affected by graphitization. FCC, catalytic reformer and ______.
- A. Alky
- B. Hydrotreater
- C. Coker
- D. Hydrocracker
Answer: C
NEW QUESTION # 24
Cracking of a metal due to stress relaxation during PWHT or in service at elevated temperatures is called ______. It is most often found in heavy wall sections.
- A. None of the above
- B. Reheat cracking
- C. Step-like cracking
- D. Thermal cracking
Answer: B
NEW QUESTION # 25
________ is a form of erosion caused by the formation and instantaneous collapse of innumerable tiny vapor bubbles.
- A. Condensate corrosion
- B. Cavitation
- C. Dew-Point corrosion
- D. Atmospheric corrosion
Answer: B
NEW QUESTION # 26
Damage from sigma phase appears in the form of ________.
- A. Hardness
- B. Ductility
- C. Cracking
- D. Corrosion
Answer: C
Explanation:
Explanation/Reference:
NEW QUESTION # 27
Increasing chromium content in the alloy improves resistance to sulfidation. However, there is little improvement with increasing chromium content until about ________ Cr.
- A. 3-5
- B. 9-12
- C. 7-9
- D. 5-7
Answer: C
NEW QUESTION # 28
An inspector observes sharp-edged pitting in piping immediately downstream from an orifice. This damage has most likely resulted from which damage mechanism?
- A. Flashing
- B. Turbulence
- C. Erosion
- D. Cavitation
Answer: C
Explanation:
According to API RP 571 Section 5.4.2 (Erosion and Erosion/Corrosion):
"Erosion can occur downstream of flow disturbances such as control valves, orifice plates, elbows... It is characterized by localized metal loss with a directional pattern such as grooves or sharp-edged pits in areas of high velocity or turbulence." Cavitation and flashing cause damage with different signatures like pitting and spongy surface texture, while sharp-edged pitting strongly indicates erosion, especially downstream of flow restriction devices.
Thus, the correct answer is Option C (Erosion).
NEW QUESTION # 29
Sulfidation is also known as ____________.
- A. None of the above
- B. Sulfidic corrosion
- C. Sulfur corrosion
- D. Sulfate corrosion
Answer: B
NEW QUESTION # 30
Nitriding layers are magnetic. Therefore, _________ should be checked for magnetism as an initial screening for nitriding.
- A. 300 Series SS
- B. Low alloy steel
- C. Duplex SS
- D. 400 Series SS
Answer: A
NEW QUESTION # 31
Polythionic acid stress corrosion cracking (PTASCC) can be detected by:
- A. Liquid penetrant testing
- B. Magnetic particle testing
- C. Ultrasonic thickness measurements
- D. Hardness measurements
Answer: A
Explanation:
From API RP 571 Section 5.1.2.5 (Polythionic Acid Stress Corrosion Cracking):
"PTASCC typically occurs on the surface of stainless steels that have been sensitized. Since cracks are open to the surface, liquid penetrant testing (PT) is the most effective detection method."
* Magnetic particle testing is ineffective for non-magnetic materials like austenitic stainless steels.
* UT is less effective for fine surface-connected cracks.
* Hardness testing is unrelated to detecting cracking.
Thus, Option C (Liquid penetrant testing) is the correct and preferred method for detecting PTASCC.
NEW QUESTION # 32
With hydrofluoric acid corrosion, corrosion rates increase with _______ temperatures and ______ HF concentrations.
- A. Increasing, decreasing
- B. Increasing, increasing
- C. Decreasing, increasing
- D. Decreasing, decreasing
Answer: A
NEW QUESTION # 33
Which of these materials are susceptible to creep damage?
- A. All of the above
- B. Stainless steel
- C. Carbon steel
- D. Low alloy steel
Answer: A
NEW QUESTION # 34
The severity of hydrochloric acid corrosion ________ with _________ HCl concentration and increasing temperatures.
- A. Increases, decreasing
- B. Decreases, decreasing
- C. Increases, increasing
- D. Decreases, increasing
Answer: C
NEW QUESTION # 35
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. Embrittlement cannot be prevented
- B. Use of a controlled pressurization sequence
- C. Postweld heat treatment (PWHT) of repairs
- D. Specification of Charpy V-notch impact test
Answer: D
Explanation:
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°F and 1070°F (343°C-577°C), 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.
NEW QUESTION # 36
Which of the following alkanolamine systems is the most aggressive in causing amine corrosion?
- A. Diglycolamine (DGA)
- B. Monoethanolamine (MEA)
- C. Methyldiethanolamine (MDEA)
- D. Diethanolamine (DEA)
Answer: B
NEW QUESTION # 37
What test is used to determine a material's toughness?
- A. Metallography
- B. Guided bend test
- C. Physical fitness test
- D. Tension test
- E. Charpy impact test
Answer: E
NEW QUESTION # 38
Corrosion in boiler feedwater and condensate return systems is usually the result of dissolved gases, oxygen and ________.
- A. Carbon dioxide
- B. Material properties
- C. H²S
- D. Carbon monoxide
Answer: A
NEW QUESTION # 39
An inspector has discovered significant cracking in a T-joint where hot and cold hydrogen-containing streams are mixing in a hydroprocess unit. What damage mechanism should the inspector suspect is the cause?
- A. Injection point corrosion
- B. Hydrogen embrittlement
- C. Thermal fatigue
- D. Mixing point corrosion
Answer: C
Explanation:
API RP 571 on Thermal Fatigue:
"Mixing of hot and cold streams, particularly where hydrogen is present, can induce thermal cycling stresses, leading to thermal fatigue cracking, especially at fittings like tees."
"Hydrogen embrittlement typically affects stressed zones, but this pattern strongly indicates thermal fatigue." So the correct answer is C - Thermal fatigue.
NEW QUESTION # 40
Proper application of ________ will control but not eliminate microbes that cause MIC so that continued treatment is necessary.
- A. None of the above
- B. Ozone
- C. Biocides
- D. Caustic
Answer: C
NEW QUESTION # 41
......
Real Updated API-571 Questions & Answers Pass Your Exam Easily: https://www.testpassking.com/API-571-exam-testking-pass.html
Easily To Pass New API-571 Verified & Correct Answers: https://drive.google.com/open?id=1bt1sg_l4P_rS7pooFnpALIlxPQlFA6eR