API 510 Exam Questions and Answers
(Latest Update 2026)
Where would you find the definition of an alteration? -
correct answer ✅In API 510 paragraph 3.1.1
Where would you find the information about responsibilities before
entering a vessel? -
correct answer ✅In API 510, paragraph 5.3.3
What will cause sub-surface cracking? -
correct answer ✅Hydrogen-induced cracking and wet hydrogen
sulfide cracking (API 510, paragraph 5.4.1(c)).
What damage mechanisms cause metallurgical changes? -
correct answer ✅Graphitization, temper embrittlement, and
hydrogen embrittlement (API 510, paragraph 5.4.1(e)).
At what temperature will low-alloy steels experience a reduction in
toughness? -
correct answer ✅At temperatures above 650° F (API 510,
paragraph 3.1.69).
,API 510 Exam Questions and Answers
(Latest Update 2026)
What damage mechanism causes macro cracking? -
correct answer ✅HTHA (High temperature hydrogen attack (API
510, paragraph 5.4.1(d))).
Alteration -
correct answer ✅Physical change in any component that has
design implications affecting pressure containing ability beyond the
scope described in existing data reports.
What are NOT considered "alterations?" -
correct answer ✅Any comparable or duplicate replacement, the
addition of any reinforced nozzle less than or equal to the size of
existing reinforced nozzles, and the addition of nozzles not
requiring reinforcement.
Inspection -
correct answer ✅The external, internal, or on-stream evaluation of
the condition of a vessel conducted by the authorized inspector or
his/her designee in accordance with API 510 code.
Examination -
correct answer ✅Process by which an examiner or inspector
,API 510 Exam Questions and Answers
(Latest Update 2026)
investigates a component using NDE in accordance with approved
NDE procedures
Major Repair -
correct answer ✅Any work not considered an alteration that
removes and replaces a major part of the pressure boundary other
than a nozzle.
When does a major repair classify as an alteration? -
correct answer ✅When any restorative work results in a change to
the design temperature, MAT, or MAWP. Requirements for re-rating
shall be satisfied.
What is low-alloy steel? -
correct answer ✅Family of steels containing up to 9% chromium
and other alloying additions for high temperature strength, and
creep resistance.
What are some low-alloy steels commonly encountered in refining?
-
correct answer ✅C-0.5Mo, Mn-0.5Mo, 1Cr-0.5Mo, 1.25Cr-0.5Mo,
2.25Cr-1.0Mo, 5Cr-0.5Mo, and 9Cr-1Mo. These are considered
ferritic steels.
, API 510 Exam Questions and Answers
(Latest Update 2026)
What constitutes a nickel-based alloy? -
correct answer ✅An alloy with >30% Nickel. Some alloys include
200, 400, K-500, 800, 800H, 825, 600H, 617, 625, 718, X-750, and
C276.
Imperfection -
correct answer ✅Flaws or other discontinuities noted during
inspection or examination that may or may not exceed the
applicable acceptance criteria.
Indication -
correct answer ✅A response or evidence resulting from the
application of an NDE that may be non relevant, flawed, or
defective upon further analysis. (A signal of a discontinuity in the
material)
Defect -
correct answer ✅Discontinuity(s) that render a part or product
unable to meet minimum applicable acceptance standards or
specifications. Designates rejectability.
(Latest Update 2026)
Where would you find the definition of an alteration? -
correct answer ✅In API 510 paragraph 3.1.1
Where would you find the information about responsibilities before
entering a vessel? -
correct answer ✅In API 510, paragraph 5.3.3
What will cause sub-surface cracking? -
correct answer ✅Hydrogen-induced cracking and wet hydrogen
sulfide cracking (API 510, paragraph 5.4.1(c)).
What damage mechanisms cause metallurgical changes? -
correct answer ✅Graphitization, temper embrittlement, and
hydrogen embrittlement (API 510, paragraph 5.4.1(e)).
At what temperature will low-alloy steels experience a reduction in
toughness? -
correct answer ✅At temperatures above 650° F (API 510,
paragraph 3.1.69).
,API 510 Exam Questions and Answers
(Latest Update 2026)
What damage mechanism causes macro cracking? -
correct answer ✅HTHA (High temperature hydrogen attack (API
510, paragraph 5.4.1(d))).
Alteration -
correct answer ✅Physical change in any component that has
design implications affecting pressure containing ability beyond the
scope described in existing data reports.
What are NOT considered "alterations?" -
correct answer ✅Any comparable or duplicate replacement, the
addition of any reinforced nozzle less than or equal to the size of
existing reinforced nozzles, and the addition of nozzles not
requiring reinforcement.
Inspection -
correct answer ✅The external, internal, or on-stream evaluation of
the condition of a vessel conducted by the authorized inspector or
his/her designee in accordance with API 510 code.
Examination -
correct answer ✅Process by which an examiner or inspector
,API 510 Exam Questions and Answers
(Latest Update 2026)
investigates a component using NDE in accordance with approved
NDE procedures
Major Repair -
correct answer ✅Any work not considered an alteration that
removes and replaces a major part of the pressure boundary other
than a nozzle.
When does a major repair classify as an alteration? -
correct answer ✅When any restorative work results in a change to
the design temperature, MAT, or MAWP. Requirements for re-rating
shall be satisfied.
What is low-alloy steel? -
correct answer ✅Family of steels containing up to 9% chromium
and other alloying additions for high temperature strength, and
creep resistance.
What are some low-alloy steels commonly encountered in refining?
-
correct answer ✅C-0.5Mo, Mn-0.5Mo, 1Cr-0.5Mo, 1.25Cr-0.5Mo,
2.25Cr-1.0Mo, 5Cr-0.5Mo, and 9Cr-1Mo. These are considered
ferritic steels.
, API 510 Exam Questions and Answers
(Latest Update 2026)
What constitutes a nickel-based alloy? -
correct answer ✅An alloy with >30% Nickel. Some alloys include
200, 400, K-500, 800, 800H, 825, 600H, 617, 625, 718, X-750, and
C276.
Imperfection -
correct answer ✅Flaws or other discontinuities noted during
inspection or examination that may or may not exceed the
applicable acceptance criteria.
Indication -
correct answer ✅A response or evidence resulting from the
application of an NDE that may be non relevant, flawed, or
defective upon further analysis. (A signal of a discontinuity in the
material)
Defect -
correct answer ✅Discontinuity(s) that render a part or product
unable to meet minimum applicable acceptance standards or
specifications. Designates rejectability.
