Section 4 Flashcards
Suitability for Service
A tank roof shall be repaired or replaced when the thickness in a 100 in2 area is less than?
0.09”
API 653 par 4.2.1.2
Who determines the inspection method to be used to evaluate roof support members?
Tank Inspector
API 653 par 4.2.2.1
What performing an internal inspection, close attention must be made to what members?
Pipe columns
API 653 par 4.2.2.1
What must be repaired on a floating roof if discovered during inspections?
Cracked, punctured areas or areas that may hole through before the next inspection
API 653 par 4.2.3.1 thru 4.2.3.4
What code and code section(s) should be used to evaluate floating roofs?
API 650 Annex C for external floating roofs and API 650 Annex H for internal floating roofs
API 653 par 4.2.3.4
What code can be used to evaluate pits or Localized Thin Areas (LTAs) as an alternative to evaluation using API 653?
ASME Section VIII, Div 2
API 653 par 4.3.3.6
What API 650 Appendix is used to evaluate frangible roof joints
Appendix F
API 653 par 4.2.4.1
What is the temperature range when API 650 Annex M is required to evaluate a tank?
> 200°F, but less than 500°F
API 653 par 4.3.10
When evaluating a LTA, how many UT reading are required to be taken over each vertical line?
Minimum of 5
API 653 par 4.3.2.1c
What joint efficiency should be used when evaluating the retirement thickness in a corroded plate, and the (Locally Thinned Area) LTA is away from welds or joints by at least the greater of 1” or twice the plate thickness?
1
API 653 par 4.3.3.1 (‘E’ description)
What is the minimum required thickness allowed for Tmin of a shell course
0.100”
API 653 par 4.3.3.1 (Tmin description)
What is the ‘standard’ joint efficiency in API 650 when evaluating the retirement thickness of an unknown material for a butt weld?
1
API 653 par 4.3.3.1 & Table 4.2
Above what tank diameter should the varible design point method be used to calculate the minimum required shell thickness?
> 200’ in diameter
API 653 par 4.3.3.4 & API 650 par 5.6.4
What joint efficiency should be used when evaluating the retirement thickness in a corroded plate, and the LTA (Locally Thinned Area) is 6” or more away from the rivets?
1
API 653 par 4.3.4.1
When calculating the minimum required thickness for a corroded section of tank shell, what is the minimum distance that corrosion must be away from a rivet to get a joint efficiency of 1?
6”
API 653 par 4.3.4.1
What codes can be used to evaluate shell welds?
- API 653
- API 650
- API 579
API 653 par 4.3.8
A welded tank is considered to be in ‘evelated temperature’ service when the operating themperature exceeds ____°F, but less than _ °F?
200°F & 500°F
API 653 par 4.3.10
What yield strength should be used if the shell material is unknown?
30,000 PSI
API 653 par 4.3.10.1.1a
How often must the tank bottom be evaluated?
Less than or equal to Internal Inspection Internal
API 653 par 4.4.1
Can the tank bottom be evaluated without entry into the tank? If so, how?
YES, by use of leak detection test/monitoring systems that could detect a leak
API 653 par 4.4.1
Why would you monitor foundation settlement?
To assess the integrity of the tank bottom
API 653 par 4.4.1
What is the meaning of RPS?
Release Prevention System
API 653 par 4.4.3 Tank Bottom Release Prevention Systems
What is the purpose of a Tank Bottom Release Prevention System (RPS)?
To maintain tank integrity and protect the environment
API 653 par 4.4.3
What is the meaning of RPB?
Release Prevention Barrier:
An RPB includes steel bottoms, synthetic materials, clay liners, concrete pads, and all other barriers or combinations
of barriers placed in the bottom of or under a tank, which have the function of:
1) preventing the escape of released material, and
2) containing or channeling released material for leak detection
API 653 par 4.4.3.5
What is the purpose of a RPB?
Prevent a release of material and enable leak detection
API 653 par 4.4.3.5
What are two NDE methods that are normally used to determine tank bottom corrosion?
UT & MFL
API 653 par 4.4.4
What is the minimum thickness allowed for a tank’s bottom plate by the next inspection when there is a mean of detection and containment?
0.05”
API 653 par 4.4.5.3 and Tab
What is the minimum thickness allowed for a tank’s bottom plate by the next inspection when there is no means of detection and containment?
0.100”
API 653 par 4.4.5.3 & Table 4.4
What is the minimum thickness allowed for a tank’s bottom plate by the next inspection when there is a applied tank bottom reinforced lining that is greater than 0.05” thick?
0.05”
API 653 par 4.4.5.3 & Table 4.4
What is the thinnest that a shell botom plate can be in the critical zone?
Smaller of ½ of the original plate thickness (not including corrosion allowance) or 50% of tmin, but not less than 0.100”
API 653 par 4.4.5.4
What is the minimum required thickness of the projection of the bottom plate outside the bottom-to-shell, for an inservice tank?
0.100”
API 653 par 4.4.5.7
How far must the bottom plate extend past the bottom-to-shell (toe of the botom-to-shell weld), for an in-service tank?
3/8”
API 653 par 4.4.5.7
What is the minimum required thickness of the annular plate?
0.100”
API 653 par 4.4.6.1
What is the minimum required thickness of the annualar plate that contain a product with a specific gravity of less than 1?
0.170”
API 653 par 4.4.6.2 & Table 4.5
