API 653 Documentation 2 — Questions and Answers
Question 1: When documenting thickness measurements on an aboveground storage tank, which reference point must be clearly identified on the sketch?
- The tank color and coating type
- The location of each measurement point relative to a fixed reference (Correct answer)
- The name of the ultrasonic testing technician
- The ambient temperature during inspection
Correct answer: The location of each measurement point relative to a fixed reference
API 653 requires that all thickness measurement locations be clearly identified relative to a fixed reference point so readings can be reproduced in future inspections.
Question 2: Which document provides the original design basis and is critical for establishing minimum acceptable shell thickness under API 653?
- The tank inspection log
- The API 653 inspection checklist
- The original manufacturer's data report (e.g., API 650 Appendix I form) (Correct answer)
- The environmental compliance permit
Correct answer: The original manufacturer's data report (e.g., API 650 Appendix I form)
The original manufacturer's data report contains the design parameters, materials of construction, and nominal thickness that serve as the baseline for fitness-for-service evaluations.
Question 3: Under API 653, when a repair is made to a tank shell, what documentation must be prepared and retained?
- Only a verbal notification to the owner
- A repair record signed by a qualified inspector, describing the repair method and materials (Correct answer)
- A standard work order from the maintenance department
- An insurance claim form
Correct answer: A repair record signed by a qualified inspector, describing the repair method and materials
API 653 Section 9 requires that all repairs be documented with a repair record that includes the method, materials, extent of the repair, and approval by a qualified API 653 inspector.
Question 4: What is the purpose of maintaining a tank history file according to API 653?
- To satisfy insurance premium discounts
- To track aesthetic changes such as paint color
- To provide a continuous record of inspections, repairs, alterations, and service changes for fitness-for-service decisions (Correct answer)
- To document employee training records
Correct answer: To provide a continuous record of inspections, repairs, alterations, and service changes for fitness-for-service decisions
A tank history file consolidates all inspection results, repair records, and service changes, enabling informed fitness-for-service and remaining-life assessments over the tank's operational life.
Question 5: When an alteration is made to a tank under API 653, which statement best describes the documentation requirement?
- Documentation is only required if the alteration changes the tank capacity
- Alterations must be documented as thoroughly as original construction, including design calculations and inspector certification (Correct answer)
- A simple memo to the plant manager is sufficient
- Documentation is required only for welded alterations, not for bolt-on additions
Correct answer: Alterations must be documented as thoroughly as original construction, including design calculations and inspector certification
API 653 treats alterations with the same rigor as original construction, requiring full documentation of design basis, materials, welding procedures, and certified inspector review.
Question 6: According to API 653, how long should tank inspection records generally be retained?
- At least 1 year
- At least 5 years
- For the life of the tank (Correct answer)
- Until the next scheduled inspection
Correct answer: For the life of the tank
API 653 recommends that inspection records be kept for the life of the tank because historical data is essential for calculating corrosion rates and determining future inspection intervals.
Question 7: If original thickness records for a tank are unavailable, what does API 653 permit the inspector to use as a baseline?
- The thinnest reading found anywhere on the tank
- Nominal thickness from original design documents or the appropriate API standard for the tank's construction date (Correct answer)
- Thickness measurements from a similar tank in the same facility
- An assumed value of 0.25 inches for all shell courses
Correct answer: Nominal thickness from original design documents or the appropriate API standard for the tank's construction date
When original records are missing, API 653 allows the inspector to use nominal thickness from the applicable construction standard or original design documents as the starting baseline.
API 653 Documentation 2
When documenting thickness measurements on an aboveground storage tank, which reference point must be clearly identified on the sketch?