API 653: tank inspection, repair,
alteration, and reconstruction
What type of tanks does the standard apply? API 653 1.1.1 - correct answer-Steel storage
tanks built to API 650 and its predecessor API 12C
In case of a parent conflict between the requirements of API 650 and API 653 which
standard Govern? API 653 1.1.2 - correct answer-API 653
What is meant by the term alteration? What are some examples of alterations? API 653 3.1 -
correct answer-Anything that changes the physical dimensions
Man way 12" nozzles
What is the break over point? API 653 3.6 - correct answer-The area on the tank bottom
where settlement begins
What is meant by the term repair? What are some examples of repairs? API 653 3.15 -
correct answer-Any work necessary to restore and maintain a tank to a condition suitable for
safe operation
What conditions would Necessitate the repair or replacement of a roof plate? API 653
4.2.1.2 - correct answer-Corrosion to a thickness of .09 in any 100 sq in area. Holes
What possibility must be given particular attention when inspecting pipe columns supporting
fixed roofs? API 653 4.2.2 - correct answer-Severe internal corrosion
When a tank is to undergo a change in service what are five factors that should be
considered when evaluating the roof and roof to shell junction? API 653 4.2.4 - correct
answer-A) internal pressure
B) external pressure
C) elevated temp
D) Low temp
E) normal and emergency venting
When determining controlling thickness in shell courses widely scattered pits may be ignored
provided that two conditions are met. What are these two conditions? API 653 4.3.2.2 -
correct answer-A) hope it being less than 1/2 the original shell thickness
B) The sum of dimensions does not exceed 2 inches in a 8 inch length
What are some typical forms of shell distortion? API 653 4.3.5.1 - correct answer-Out of
round, buckled sides, flat spots, peeking and banding at weld joints
Do temperature cracks in concrete seriously affect the strength of the concrete foundation?
What can temperature cracks in concrete eventually result in? API 653 4.5.1.2 - correct
answer-No
, Potential access points for moisture
What are 12 historical causes of tank bottom leakage listed in this document? API 653 4.4.2
- correct answer-A) internal pitting
B) corrosion of weld joints
C) cracking weld joints
D) stress on bottom plates from settlement and roof supports
E) underside corrosion
F) in adequate drainage
G) lack of annular ring
H) uneven settlement
I) movement in roof supports
J) Rock or gravel foundation pads
K) non-homogenous fill under tank
J) inadequate supported sumps
What problems are indicated by distortion of anchor bolts and excessive cracking of the
concrete in which they are in embedded? API 653 4.5.3 - correct answer-Serious foundation
settlement
Overpressure uplift condition
Below what shell thickness is the potential for failure due to brittle fracture minimal? What
can be done to gain assurance against brittle fracture? API 653 5.3.4, 5.3.5 - correct
answer-.5
Increase the metal temp by heating the tank contents
What are 12 factors that should be considered when determining inspection intervals for
storage tanks? API 653 6.2.1 - correct answer-A) nature of stored product
B) results of visual maintenance checks
C) corrosion rates
D) condition of previous inspections
E) corrosion prevention systems
F) methods and materials of construction and repair
G) Location of tank
H) risk of water or air pollution
I) leak detection system
J) change in operating modes fill and emptying
K) jurisdictional requirements
I) change in service
How often should routine in-service inspections be conducted? API 653 6.3.1.2 - correct
answer-Depends on condition of site not to exceed one month
What can be determined by performing external ultrasonic thickness measurements of the
tank shell? Can ultrasonic thickness measurements be conducted while the tank is in
service? API 653 6.3.3.1 - correct answer-Corrosion rates, integrity of the shell
Yes
alteration, and reconstruction
What type of tanks does the standard apply? API 653 1.1.1 - correct answer-Steel storage
tanks built to API 650 and its predecessor API 12C
In case of a parent conflict between the requirements of API 650 and API 653 which
standard Govern? API 653 1.1.2 - correct answer-API 653
What is meant by the term alteration? What are some examples of alterations? API 653 3.1 -
correct answer-Anything that changes the physical dimensions
Man way 12" nozzles
What is the break over point? API 653 3.6 - correct answer-The area on the tank bottom
where settlement begins
What is meant by the term repair? What are some examples of repairs? API 653 3.15 -
correct answer-Any work necessary to restore and maintain a tank to a condition suitable for
safe operation
What conditions would Necessitate the repair or replacement of a roof plate? API 653
4.2.1.2 - correct answer-Corrosion to a thickness of .09 in any 100 sq in area. Holes
What possibility must be given particular attention when inspecting pipe columns supporting
fixed roofs? API 653 4.2.2 - correct answer-Severe internal corrosion
When a tank is to undergo a change in service what are five factors that should be
considered when evaluating the roof and roof to shell junction? API 653 4.2.4 - correct
answer-A) internal pressure
B) external pressure
C) elevated temp
D) Low temp
E) normal and emergency venting
When determining controlling thickness in shell courses widely scattered pits may be ignored
provided that two conditions are met. What are these two conditions? API 653 4.3.2.2 -
correct answer-A) hope it being less than 1/2 the original shell thickness
B) The sum of dimensions does not exceed 2 inches in a 8 inch length
What are some typical forms of shell distortion? API 653 4.3.5.1 - correct answer-Out of
round, buckled sides, flat spots, peeking and banding at weld joints
Do temperature cracks in concrete seriously affect the strength of the concrete foundation?
What can temperature cracks in concrete eventually result in? API 653 4.5.1.2 - correct
answer-No
, Potential access points for moisture
What are 12 historical causes of tank bottom leakage listed in this document? API 653 4.4.2
- correct answer-A) internal pitting
B) corrosion of weld joints
C) cracking weld joints
D) stress on bottom plates from settlement and roof supports
E) underside corrosion
F) in adequate drainage
G) lack of annular ring
H) uneven settlement
I) movement in roof supports
J) Rock or gravel foundation pads
K) non-homogenous fill under tank
J) inadequate supported sumps
What problems are indicated by distortion of anchor bolts and excessive cracking of the
concrete in which they are in embedded? API 653 4.5.3 - correct answer-Serious foundation
settlement
Overpressure uplift condition
Below what shell thickness is the potential for failure due to brittle fracture minimal? What
can be done to gain assurance against brittle fracture? API 653 5.3.4, 5.3.5 - correct
answer-.5
Increase the metal temp by heating the tank contents
What are 12 factors that should be considered when determining inspection intervals for
storage tanks? API 653 6.2.1 - correct answer-A) nature of stored product
B) results of visual maintenance checks
C) corrosion rates
D) condition of previous inspections
E) corrosion prevention systems
F) methods and materials of construction and repair
G) Location of tank
H) risk of water or air pollution
I) leak detection system
J) change in operating modes fill and emptying
K) jurisdictional requirements
I) change in service
How often should routine in-service inspections be conducted? API 653 6.3.1.2 - correct
answer-Depends on condition of site not to exceed one month
What can be determined by performing external ultrasonic thickness measurements of the
tank shell? Can ultrasonic thickness measurements be conducted while the tank is in
service? API 653 6.3.3.1 - correct answer-Corrosion rates, integrity of the shell
Yes
