API 571 Practice Exam #1 Questions
with Complete Solutions22
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% - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-B
4.2.16.3
Temper embrittlement primarily occurs in:
with Complete Solutions22
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% - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-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 - ANSWERS-B
4.2.16.3
Temper embrittlement primarily occurs in:
