API 653 Intro
What does API 653 cover? - correct answer-Steel storage tanks built to API 650 and its
predecessor API 126. Provides minimum requirements for maintaining integrity of such tanks
after they have been placed in service and addresses inspection, repair, alterations,
relocation, and reconstruction.
What is the scope of API 653 limited to? - correct answer-scope is limited to tank foundation,
bottom, shell, structure, roof, attached appurtenances, and nozzles to the face of the first
flange, first threaded joint, or first welding in connection.
What shall govern if there is a conflict between API 653 and API 126? - correct answer-API
653 shall govern for tanks that have been put in service.
Can the principles of API 653 be applied to tanks not built using the specifications of API
650? - correct answer-Yes, storage tank owners/operators, based on the consideration of
specific construction and operating details, may apply this standard to any steel tank
constructed in accordance with a tank specification.
What organizations is API 653 intended to be used by? - correct answer-Organizations that
maintain or have access to engineering and inspection personnel technically trained and
experienced in tank design, fabrication, repair, construction, and inspection.
Since API 653 does not contain rules or guidelines to cover all the varied conditions which
may occur in an existing tank, what shall the level of integrity be equal to if no design and
construction details of a tank are given and are not available in the as-built standard? -
correct answer-details that will provide a level of integrity equal to the level provided by the
current edition of API 650 must be used.
Who has the ultimate responsibility for complying with the standards of AI 653? - correct
answer-Owner/Operator
What governs if API 653 presents a direct or implied conflict with a jurisdictional regulation? -
correct answer-The regulation will govern, unless the requirement from API 653 is more
stringent.
What API standards shall be used to develop safe work procedures? - correct answer-API
standard 2015 and API 2217A and shall include safeguards for personnel health and safety,
prevention of accidental fires and explosions, and prevention of property damage.
Define- Break Over Point - correct answer-The area on a tank bottom where settlement
begins.
Define- Candidate Tank - correct answer-The tank(s) for which corrosion rates are not known
, Define- Control Tank - correct answer-the tank(s) for which corrosion rates and service
history are known.
Define- Critical Zone - correct answer-The portion of tank bottom or annular plate within 3" of
the inside edge of the shell, measured radially inward.
Define- Insert Plate - correct answer-A steel plate that replaced part of a shell plate with a
nominal thickness no more than 1/8" greater than the nominal thickness of the adjoining
material. When an insert plate is equal to the full height of a shell ring, it is considered to be
a shell plate.
Define- Major Alteration/or Major Repair - correct answer-An alteration or repair that includes
the following:
a) installing a shell penetration larger than NPS 12 beneath the liquid level
b) installing a bottom penetration within 12" of the tank shell
c) removing and replacing or adding a a shell plate beneath the liquid level where the
longest dimension of the replacement plate exceeds 12"
d) removing or replacing annular late material where the longest dimension of the
replacement plate exceeds 12"
e) complete or partial (more than 1/2 of the weld thickness) removal and replacement of
more than 12" of vertical weld joining shell plates or radial weld joining the annular plate.
f) installing new bottom plate (note: installation of a partition of a new bottom as described in
12.3.3.3 is not defined as a major repair)
g) removing and replacing part of the weld attaching the shell to bottom, or to the annulaer
plate ring, in excess of the amounts listed in 12.3.2.5.1a
h) jacking a tank shell
Define- Recognized Toughness - correct answer-A condition that exists when the material of
a component is deemed acceptable for use by the provisions of any of the following sections
of API 653:
A) Sec. 5.3.2 (Based in edition of standard of tanks original design, or by coupon testing)
B) Sec. 5.3.5 (Based on thickness)
C) Sec. 5.3.6 ( Based on lowest design material temperature)
D) Sec. 5.3.8 (Based on exemption curves)
Define- Thickened Insert Plate - correct answer-A steel plate that replaces part of a shell
plate with a nominal thickness that is greater that the nominal thickness of the adjoining
material by more than 1/8"
Define- Unknown Toughness - correct answer-A condition that exists when it cannot be
demonstrated that the material of a component satisfies the definitions of recognized
toughness
What average thickness of corroded roof plates shall cause the roof plate to be repaired or
replaced? - correct answer-Roof plate corroded to an average thickness of less than .09" in
any 100in^2 area or roof plates with holes through the roof plate shall be repaired or
replaced.
What does API 653 cover? - correct answer-Steel storage tanks built to API 650 and its
predecessor API 126. Provides minimum requirements for maintaining integrity of such tanks
after they have been placed in service and addresses inspection, repair, alterations,
relocation, and reconstruction.
What is the scope of API 653 limited to? - correct answer-scope is limited to tank foundation,
bottom, shell, structure, roof, attached appurtenances, and nozzles to the face of the first
flange, first threaded joint, or first welding in connection.
What shall govern if there is a conflict between API 653 and API 126? - correct answer-API
653 shall govern for tanks that have been put in service.
Can the principles of API 653 be applied to tanks not built using the specifications of API
650? - correct answer-Yes, storage tank owners/operators, based on the consideration of
specific construction and operating details, may apply this standard to any steel tank
constructed in accordance with a tank specification.
What organizations is API 653 intended to be used by? - correct answer-Organizations that
maintain or have access to engineering and inspection personnel technically trained and
experienced in tank design, fabrication, repair, construction, and inspection.
Since API 653 does not contain rules or guidelines to cover all the varied conditions which
may occur in an existing tank, what shall the level of integrity be equal to if no design and
construction details of a tank are given and are not available in the as-built standard? -
correct answer-details that will provide a level of integrity equal to the level provided by the
current edition of API 650 must be used.
Who has the ultimate responsibility for complying with the standards of AI 653? - correct
answer-Owner/Operator
What governs if API 653 presents a direct or implied conflict with a jurisdictional regulation? -
correct answer-The regulation will govern, unless the requirement from API 653 is more
stringent.
What API standards shall be used to develop safe work procedures? - correct answer-API
standard 2015 and API 2217A and shall include safeguards for personnel health and safety,
prevention of accidental fires and explosions, and prevention of property damage.
Define- Break Over Point - correct answer-The area on a tank bottom where settlement
begins.
Define- Candidate Tank - correct answer-The tank(s) for which corrosion rates are not known
, Define- Control Tank - correct answer-the tank(s) for which corrosion rates and service
history are known.
Define- Critical Zone - correct answer-The portion of tank bottom or annular plate within 3" of
the inside edge of the shell, measured radially inward.
Define- Insert Plate - correct answer-A steel plate that replaced part of a shell plate with a
nominal thickness no more than 1/8" greater than the nominal thickness of the adjoining
material. When an insert plate is equal to the full height of a shell ring, it is considered to be
a shell plate.
Define- Major Alteration/or Major Repair - correct answer-An alteration or repair that includes
the following:
a) installing a shell penetration larger than NPS 12 beneath the liquid level
b) installing a bottom penetration within 12" of the tank shell
c) removing and replacing or adding a a shell plate beneath the liquid level where the
longest dimension of the replacement plate exceeds 12"
d) removing or replacing annular late material where the longest dimension of the
replacement plate exceeds 12"
e) complete or partial (more than 1/2 of the weld thickness) removal and replacement of
more than 12" of vertical weld joining shell plates or radial weld joining the annular plate.
f) installing new bottom plate (note: installation of a partition of a new bottom as described in
12.3.3.3 is not defined as a major repair)
g) removing and replacing part of the weld attaching the shell to bottom, or to the annulaer
plate ring, in excess of the amounts listed in 12.3.2.5.1a
h) jacking a tank shell
Define- Recognized Toughness - correct answer-A condition that exists when the material of
a component is deemed acceptable for use by the provisions of any of the following sections
of API 653:
A) Sec. 5.3.2 (Based in edition of standard of tanks original design, or by coupon testing)
B) Sec. 5.3.5 (Based on thickness)
C) Sec. 5.3.6 ( Based on lowest design material temperature)
D) Sec. 5.3.8 (Based on exemption curves)
Define- Thickened Insert Plate - correct answer-A steel plate that replaces part of a shell
plate with a nominal thickness that is greater that the nominal thickness of the adjoining
material by more than 1/8"
Define- Unknown Toughness - correct answer-A condition that exists when it cannot be
demonstrated that the material of a component satisfies the definitions of recognized
toughness
What average thickness of corroded roof plates shall cause the roof plate to be repaired or
replaced? - correct answer-Roof plate corroded to an average thickness of less than .09" in
any 100in^2 area or roof plates with holes through the roof plate shall be repaired or
replaced.
