API 653 Section 4
- answer4.1.1 When the results of a tank inspection show that a change has occurred
from the original physical condition of that tank, an evaluation shall be made to
determine its suitability for continued use.
- answer4.1.2 This section provides an evaluation of the suitability of an existing tank
for continued service, or for a change of service, or when making decisions involving
repairs, alterations, dismantling, relocating, or reconstructing an existing tank.
- answer4.1.3 The following list of factors for consideration is not all-inclusive for all
situations, nor is it intended to be a substitute for the engineering analysis and judgment
required for each situation:
a.internal corrosion due to the product stored or water bottoms;
b.external corrosion due to environmental exposure;
stress levels and allowable stress levels;
c.properties of the stored product such as specific d.gravity, temperature, and
corrosivity;
e. metal design temperatures at the service location of the tank;
f. external roof live load, wind, and seismic loadings;
g. tank foundation, soil, and settlement conditions;
h. chemical analysis and mechanical properties of the materials of construction;
i. distortions of the existing tank;
j. operating conditions such as filling/emptying rates and frequency
- answer4.2 Tank Roof Evaluation
4.2.1.1 The structural integrity of the roof and roof support system shall be verified
- answer4.2.1.2 Roof plates corroded to an average thickness of less than 0.09" in any
100 sq. inch area or roof plates with any holes through the roof plate shall be repaired
or replaced.
- answer4.2.2 Fixed Roofs
Roof support members (rafters, girders, columns, and bases) shall be inspected for
soundness by a method acceptable to the responsible inspector. Distorted (such as out-
of-plumb columns), corroded, and damaged members shall be evaluated and repaired
or replaced if necessary. Particular attention must be given to the possibility of severe
internal corrosion of pipe columns (corrosion may not be evidenced by external visual
inspection).
- answer4.2 Tank Roof Evaluation
4.2.2.2 When a frangible roof-to-shell joint is required, evaluate for items impacting
compliance with requirements under API 650, Section 5.10.2.6.
,Examples of some items to evaluate include tank bottom-to-shell joint corrosion or tank
roof-to-shell joint modification (such as reinforcement of the joint, attachment of
handrail, or other frangible joint area change.
- answer4.2.3 Floating Roofs
4.2.3.1 Areas of roof plates and pontoons exhibiting cracks or punctures shall be
repaired or the affected sections replaced. Holes through roof plates shall be repaired or
replaced.
- answer4.2.3.2 Areas that are pitted shall be evaluated to determine the likelihood of
through-pitting occurring prior to the next scheduled internal inspection. If so, the
affected areas shall be repaired or replaced.
- answer4.2.3.3 Roof support systems, perimeter seal systems,
appurtenances such as a roof rolling ladder, anti-rotation devices, water drain systems,
and venting systems shall be evaluated for needed repairs or replacements.
- answer4.2.3.4 Guidance for the evaluation of existing floating roofs shall be based on
the criteria of API 650, Annex C, for external floating roofs, and Annex H for internal
floating roofs. However, upgrading to meet this standard is not mandatory.
- answer4.2.4 Change of Service
4.2.4.1 Internal Pressure
All requirements of the current applicable standard (e.g. API 650, Annex F) shall be
considered in the evaluation and subsequent alterations to the tank roof and roof-to-
shell junction.
- answer4.2.4.2 External Pressure
As applicable, the roof support structure (if any), and the roof-to-shell junction shall be
evaluated for the effects of a design partial vacuum. The criteria outlined in API 650,
Annex V shall be used
- answer4.2.4.3 Operation at Elevated
Temperature:
Consider the requirements of API
650 Annex M before changing the service to operation at temperatures above 200°F.
- answer4.2.4.4 Operation at Lower
Temperature than Original Design
If the operating temperature is changed to a lower temperature than the original design,
the requirements of the current applicable standard for the lower temperature shall be
met
- answer4.2.4.5 Normal and Emergency
Venting
, 4.2.5.1 Effects of change in operating conditions (including product service and
pumping rates) on normal and emergency venting shall be considered.
- answer4.2.4.5.2 Vents shall be operation and screens shall be verified to be clear of
obstruction.
An evaluation shall be made to determine its suitability for continued use. -
answerWhen the results of a tank inspection indicates a change has occurred from the
original physical condition
- The tank shall be removed from service.
- An evaluation shall be made to determine its suitability for continued use.
- The results of the inspection shall be recorded and presented to the owner/operator.
- The legal entity responsible for tanks shall be notified.
All choices are true - answerAPI 653 Provides
- an evaluation of tank suitability
For continued service
- When considering repairs, alterations, dismantling, relocating, or reconstruction
- When there is a change in service
- All choices are true
Structural Integrity - answerDuring tank roof evaluation, the BLANK?? of the roof and
support system should be verified.
- Corrosion rate
- Design needs
- Structural Integrity
- Supports
0.09 inch in any 100 square inch area - answerTank roof plates corroded to an average
thickness of less than BLANK -in any blank??? shall be repaired or replaced.
- 0.9 inch in any 100 square inch area
- 0.09 inch in any 144 square inch area (1 square foot)
- 0.09 inch in any 100 square inch area
- 0.09 inch in any 10 square inch area
Severe internal corrosion of pipe columns - answerDuring the inspection of fixed roof
support members, particular attention must be given to
- Severe external corrosion of the roof plate where support structures are attached
- Severe internal corrosion of pipe columns
- Severe internal corrosion of the roof plate where support structures are attached
- Deterioration of wind girders at the point of attachment
All roofs - answerRoof support system, perimeter seal system and appurtenances
should inspected during evaluation of
- Any roofs if owner/operator requires
- answer4.1.1 When the results of a tank inspection show that a change has occurred
from the original physical condition of that tank, an evaluation shall be made to
determine its suitability for continued use.
- answer4.1.2 This section provides an evaluation of the suitability of an existing tank
for continued service, or for a change of service, or when making decisions involving
repairs, alterations, dismantling, relocating, or reconstructing an existing tank.
- answer4.1.3 The following list of factors for consideration is not all-inclusive for all
situations, nor is it intended to be a substitute for the engineering analysis and judgment
required for each situation:
a.internal corrosion due to the product stored or water bottoms;
b.external corrosion due to environmental exposure;
stress levels and allowable stress levels;
c.properties of the stored product such as specific d.gravity, temperature, and
corrosivity;
e. metal design temperatures at the service location of the tank;
f. external roof live load, wind, and seismic loadings;
g. tank foundation, soil, and settlement conditions;
h. chemical analysis and mechanical properties of the materials of construction;
i. distortions of the existing tank;
j. operating conditions such as filling/emptying rates and frequency
- answer4.2 Tank Roof Evaluation
4.2.1.1 The structural integrity of the roof and roof support system shall be verified
- answer4.2.1.2 Roof plates corroded to an average thickness of less than 0.09" in any
100 sq. inch area or roof plates with any holes through the roof plate shall be repaired
or replaced.
- answer4.2.2 Fixed Roofs
Roof support members (rafters, girders, columns, and bases) shall be inspected for
soundness by a method acceptable to the responsible inspector. Distorted (such as out-
of-plumb columns), corroded, and damaged members shall be evaluated and repaired
or replaced if necessary. Particular attention must be given to the possibility of severe
internal corrosion of pipe columns (corrosion may not be evidenced by external visual
inspection).
- answer4.2 Tank Roof Evaluation
4.2.2.2 When a frangible roof-to-shell joint is required, evaluate for items impacting
compliance with requirements under API 650, Section 5.10.2.6.
,Examples of some items to evaluate include tank bottom-to-shell joint corrosion or tank
roof-to-shell joint modification (such as reinforcement of the joint, attachment of
handrail, or other frangible joint area change.
- answer4.2.3 Floating Roofs
4.2.3.1 Areas of roof plates and pontoons exhibiting cracks or punctures shall be
repaired or the affected sections replaced. Holes through roof plates shall be repaired or
replaced.
- answer4.2.3.2 Areas that are pitted shall be evaluated to determine the likelihood of
through-pitting occurring prior to the next scheduled internal inspection. If so, the
affected areas shall be repaired or replaced.
- answer4.2.3.3 Roof support systems, perimeter seal systems,
appurtenances such as a roof rolling ladder, anti-rotation devices, water drain systems,
and venting systems shall be evaluated for needed repairs or replacements.
- answer4.2.3.4 Guidance for the evaluation of existing floating roofs shall be based on
the criteria of API 650, Annex C, for external floating roofs, and Annex H for internal
floating roofs. However, upgrading to meet this standard is not mandatory.
- answer4.2.4 Change of Service
4.2.4.1 Internal Pressure
All requirements of the current applicable standard (e.g. API 650, Annex F) shall be
considered in the evaluation and subsequent alterations to the tank roof and roof-to-
shell junction.
- answer4.2.4.2 External Pressure
As applicable, the roof support structure (if any), and the roof-to-shell junction shall be
evaluated for the effects of a design partial vacuum. The criteria outlined in API 650,
Annex V shall be used
- answer4.2.4.3 Operation at Elevated
Temperature:
Consider the requirements of API
650 Annex M before changing the service to operation at temperatures above 200°F.
- answer4.2.4.4 Operation at Lower
Temperature than Original Design
If the operating temperature is changed to a lower temperature than the original design,
the requirements of the current applicable standard for the lower temperature shall be
met
- answer4.2.4.5 Normal and Emergency
Venting
, 4.2.5.1 Effects of change in operating conditions (including product service and
pumping rates) on normal and emergency venting shall be considered.
- answer4.2.4.5.2 Vents shall be operation and screens shall be verified to be clear of
obstruction.
An evaluation shall be made to determine its suitability for continued use. -
answerWhen the results of a tank inspection indicates a change has occurred from the
original physical condition
- The tank shall be removed from service.
- An evaluation shall be made to determine its suitability for continued use.
- The results of the inspection shall be recorded and presented to the owner/operator.
- The legal entity responsible for tanks shall be notified.
All choices are true - answerAPI 653 Provides
- an evaluation of tank suitability
For continued service
- When considering repairs, alterations, dismantling, relocating, or reconstruction
- When there is a change in service
- All choices are true
Structural Integrity - answerDuring tank roof evaluation, the BLANK?? of the roof and
support system should be verified.
- Corrosion rate
- Design needs
- Structural Integrity
- Supports
0.09 inch in any 100 square inch area - answerTank roof plates corroded to an average
thickness of less than BLANK -in any blank??? shall be repaired or replaced.
- 0.9 inch in any 100 square inch area
- 0.09 inch in any 144 square inch area (1 square foot)
- 0.09 inch in any 100 square inch area
- 0.09 inch in any 10 square inch area
Severe internal corrosion of pipe columns - answerDuring the inspection of fixed roof
support members, particular attention must be given to
- Severe external corrosion of the roof plate where support structures are attached
- Severe internal corrosion of pipe columns
- Severe internal corrosion of the roof plate where support structures are attached
- Deterioration of wind girders at the point of attachment
All roofs - answerRoof support system, perimeter seal system and appurtenances
should inspected during evaluation of
- Any roofs if owner/operator requires
