API 571 PRACTICE EXAM 1 WITH CORRECT ANSWERS
At what oxygen content would many metals become flammable even at low pressures, whereas they
are non-flammable in air?
a) >10%
b) >25%
c) 20-40%
d) >40% - CORRECT ANSWER-✔✔✅B
4.2.20.1
What area of a heater burning fuel oil with numerous impurities would first suffer damage from fuel ash
corrosion.
a) shock tubes
b) radian tubes
c) tube hangers and supports
d) convection tubes - CORRECT ANSWER-✔✔✅C
4.4.6.4 c)
Hydriding of titanium is a metallurgical phenomenon in which hydrogen diffuses into the titanium and
reacts to form an embrittling hydride phase. This can result in a complete loss of ductility with no
noticeable sign of corrosion or loss in thickness. Galvanic contact between titanium and more active
materials such as carbon steel can have what affect?
a) promotes damage
b) insulates the galvanic system and decreases damage
c) insulates the galvanic system and decreases damage only if pure titanium is used (not titanium alloys)
d) all of the above - CORRECT ANSWER-✔✔✅A
5.1.3.2.3 c)
When connected to a more anodic material in cooling water:
a) titanium may suffer severe hydriding embrittlement
,b) titanium may suffer severe hydriding embrittlement below 180°F (82°C)
c) titanium becomes immune to corrosion
d) titanium becomes almost immune to corrosion - CORRECT ANSWER-✔✔✅A
4.3.4.3 k)
What form of fatigue cracking develops under the combined effects of cyclic loading and corrosion and
are evidenced by ver little plastic deformation where the final fracture may occur by mechanical
overload accompanied by plaslic deformation?
a ) corrosion fatigue
b) mechanical (vibration) fatigue
c) thermal fatigue
d) all ofthe a bove - CORRECT ANSWER-✔✔✅A
4.5.2.1
What could ammonium bisulfide corrosion also be called?
a) fuel ash corrosion
b) alkaline fuel ash corrosion
c) alkaline sour water corrosion
d) amine wa ter corrosion - CORRECT ANSWER-✔✔✅C
5.1.1.2
Typical HF alkylation units operate with 1% to 3% water in the acid, equivalent t o an HF-inwater
concentration of 97% to 99% and the temperatures are gener ally below 150°F (66°C). Under these
conditions wh at material is widely used for all equipment except where close
tolerances are required for operation (i.e., pumps, valves, instruments)?
a) carbon steel
b) 300 series stainless steels
c) duplex stainless steels
d) nickel alloys - CORRECT ANSWER-✔✔✅A
5.1.1.6.3 e)
, Amine corrosion refers to the gener al and/or localized corrosion th at occurs principally on carbon steel
in amine treating processes. Corrosion is not cau sed by the amine itself, but results from dissolved acid
gases (COz and HzS), amine degr adation products, heat stable amine salts and other contaminants.
Amine corrosion primarily occurs in which materials?
a) carbon steel
b) 300 series st ainless steels
c) ferritic stainless st eels
d) nickel alloys - CORRECT ANSWER-✔✔✅A
5.1.1.1.2
What is the most important factor related to mechanical fatigue of a piece of equipment?
a) material selection
b) equipment design
c) operating conditions
d) opera ting temper atures - CORRECT ANSWER-✔✔✅B
4.2.16.3
Temper embrittlement primarily occurs in:
a) Some low alloy steels as a result oflong term exposure from 650oF to 1070oF
b) All carbon and alloy steels as a result of long term exposure from 650oF to 1070oF
c) All cast irons and all carbon steels above 800°F
d) 2.25Cr-1Mo steels at 900oF - CORRECT ANSWER-✔✔✅D
4.2.3.2 a)
Cracking of a metal due to stress relaxation during PWHT or in service at elevated temperatures is most
often observed in heavy wall sections. This is called:
a) stress relieving corrosion cr acking
b) reheat cracking
c) hydrogen induced stress relieving cracking
At what oxygen content would many metals become flammable even at low pressures, whereas they
are non-flammable in air?
a) >10%
b) >25%
c) 20-40%
d) >40% - CORRECT ANSWER-✔✔✅B
4.2.20.1
What area of a heater burning fuel oil with numerous impurities would first suffer damage from fuel ash
corrosion.
a) shock tubes
b) radian tubes
c) tube hangers and supports
d) convection tubes - CORRECT ANSWER-✔✔✅C
4.4.6.4 c)
Hydriding of titanium is a metallurgical phenomenon in which hydrogen diffuses into the titanium and
reacts to form an embrittling hydride phase. This can result in a complete loss of ductility with no
noticeable sign of corrosion or loss in thickness. Galvanic contact between titanium and more active
materials such as carbon steel can have what affect?
a) promotes damage
b) insulates the galvanic system and decreases damage
c) insulates the galvanic system and decreases damage only if pure titanium is used (not titanium alloys)
d) all of the above - CORRECT ANSWER-✔✔✅A
5.1.3.2.3 c)
When connected to a more anodic material in cooling water:
a) titanium may suffer severe hydriding embrittlement
,b) titanium may suffer severe hydriding embrittlement below 180°F (82°C)
c) titanium becomes immune to corrosion
d) titanium becomes almost immune to corrosion - CORRECT ANSWER-✔✔✅A
4.3.4.3 k)
What form of fatigue cracking develops under the combined effects of cyclic loading and corrosion and
are evidenced by ver little plastic deformation where the final fracture may occur by mechanical
overload accompanied by plaslic deformation?
a ) corrosion fatigue
b) mechanical (vibration) fatigue
c) thermal fatigue
d) all ofthe a bove - CORRECT ANSWER-✔✔✅A
4.5.2.1
What could ammonium bisulfide corrosion also be called?
a) fuel ash corrosion
b) alkaline fuel ash corrosion
c) alkaline sour water corrosion
d) amine wa ter corrosion - CORRECT ANSWER-✔✔✅C
5.1.1.2
Typical HF alkylation units operate with 1% to 3% water in the acid, equivalent t o an HF-inwater
concentration of 97% to 99% and the temperatures are gener ally below 150°F (66°C). Under these
conditions wh at material is widely used for all equipment except where close
tolerances are required for operation (i.e., pumps, valves, instruments)?
a) carbon steel
b) 300 series stainless steels
c) duplex stainless steels
d) nickel alloys - CORRECT ANSWER-✔✔✅A
5.1.1.6.3 e)
, Amine corrosion refers to the gener al and/or localized corrosion th at occurs principally on carbon steel
in amine treating processes. Corrosion is not cau sed by the amine itself, but results from dissolved acid
gases (COz and HzS), amine degr adation products, heat stable amine salts and other contaminants.
Amine corrosion primarily occurs in which materials?
a) carbon steel
b) 300 series st ainless steels
c) ferritic stainless st eels
d) nickel alloys - CORRECT ANSWER-✔✔✅A
5.1.1.1.2
What is the most important factor related to mechanical fatigue of a piece of equipment?
a) material selection
b) equipment design
c) operating conditions
d) opera ting temper atures - CORRECT ANSWER-✔✔✅B
4.2.16.3
Temper embrittlement primarily occurs in:
a) Some low alloy steels as a result oflong term exposure from 650oF to 1070oF
b) All carbon and alloy steels as a result of long term exposure from 650oF to 1070oF
c) All cast irons and all carbon steels above 800°F
d) 2.25Cr-1Mo steels at 900oF - CORRECT ANSWER-✔✔✅D
4.2.3.2 a)
Cracking of a metal due to stress relaxation during PWHT or in service at elevated temperatures is most
often observed in heavy wall sections. This is called:
a) stress relieving corrosion cr acking
b) reheat cracking
c) hydrogen induced stress relieving cracking
