Section 9: Inspection of Buried Piping (API 570 pg 70-75) Flashcards
- Inspection of buried process piping is different from other process piping, because of:
A. The potential for significant internal corrosion that cannot be monitored
B. The potential for significant external corrosion due to corrosive soils
C. Potential overhead traffic that increases stress on pipe
D. Excess water content in soils
B. The potential for significant external corrosion due to corrosive soils
- Which of the following methods is effective in finding active external corrosion on a buried underground pipe?
A. Wenner Four-Pin
B. Cathodic protection
C. Closed-interval potential survey
D. Acoustic emission testing
C. Closed-interval potential survey
- A coated buried pipe has been in service for a number of years. What method can be used to evaluate the effectiveness of the coating?
A. ACVG
B. DCVG
C. ACPR
D. DCPR
B. DCVG
- The corrosiveness of the soil for buried piping can be determined by measuring the soil resistivity. As soil resistance increases, the soil:
A. becomes-non corrosive
B. becomes less corrosive
C. becomes more corrosive
D. clay content increases
B. becomes less corrosive
Lower levels of soil resistivity are:
A. Non-corrosive
B. Less corrosive
C. More corrosive
D. Less conductive of CP protective currents
C. More corrosive
- When measuring soil resistivity, the recommended tool to use is
A. The Wenner Four-Pin Method
B. A holiday tester
C. A close-interval potential survey
D. a CP potential survey
A. The Wenner Four-Pin Method
- When The Wenner Four-Pin Method is used to measure soil resistance, it should be done in accordance with
A. API 651
B. API 2201
C. ASTM A307
D. ASTM G57
D. ASTM G57
- When monitoring cathodic protection, refer to the requirements in:
A. API 651
B. API 2201
C. ASTM A307
D. ASTM G57
A. API 651
- Which of the following should be checked when evaluating a CP system?
A. Pipe resistance
B. Pipe-to-soil potential
C. Soil inductance
D. Soil-to-pipe current
B. Pipe-to-soil potential
- Which of the following is an acceptable way to determine the wall thickness of buried piping?
A. Intelligent pigging
B. Video cameras
C. Holiday testing
D. Close interval potential survey
A. Intelligent pigging
- Guided wave examination may be used to inspect buried piping. One installation (equipment setup) may be able to screen:
A. 15 feet or longer
B. 25 feet or longer
C. 50 feet or longer
D. 100 feet or longer
A. 15 feet or longer
- During a guided wave examination, the distance the wave travels and the accuracy of the measurements is based on several factors. Which of the following is NOT a factor?
A. Degree of corrosion
B. External coatings
C. Grade of carbon steel
D. Soil conditions
C. Grade of carbon steel
- What is the suggested interval for the above-grade visual surveillance on a buried pipe? (Open Book)
A. 6 months
B. 1 year
C. 5 years
D. 10 years
A. 6 months
- Who is responsible to ensure that the above grade visual surveillance is performed at the required intervals
A. Authorized inspector
B. Piping engineer
C. Owner / User
D. Tank farm operations supervisor
C. Owner / User
- For poorly coated buried piping systems where cathodic protecting potential are inconsistent, the pipe-to-soil potential survey may be performed every:
A. 1-2 years
B. 3-5 years
C. 5-10 years
D. 10-15 years
B. 3-5 years