570 Study Guide - Section 9 - Buried Piping Inspection Flashcards
Inspection of buried process piping is different from other process piping inspection, because of:
A. Significant internal corrosion that cannot be monitored
B. Significant external corrosion due to corrosive soils
C. Potential overhead traffic that increases stress on pipe
D. Excessive water content in soils
B. Significant external corrosion due to corrosive soils
Which of the following methods is effective in finding active corrosion on an unearthed underground pipe?
A. Wenner four-pin
B. Holiday tester
C. Close-interval potential survey
D. Acoustic emission testing
C. Close-interval potential survey
The corrosiveness of the soil for buried piping systems can be determined by measuring the soil resistivity, As soil resistivity. As soil resistance increases, the soil:
A. Become non-corrosive
B. Become less corrosive
C. Become more corrosive
D. Clay content increases
B. Become less corrosive
Lower levels or soil resistivity are:
A. Non-corrosive
B. Less corrosive
C. More corrosive
D. Less conductive of CP protective currents
C. More corrosive
Measurements of soil resistivity should be performed using:
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:
A. API 561
B. API 2201
C. ASTM A307
D. ASTM G57
A. API 561
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
Which of the following is an acceptable way to determine the wall thickness of buried piping?
A. Close interval potential survey
B. Video Cameras
C. Holiday testing
D. Excavating
D. Excavating
Which of the following is NOT a limitation on using an intelligent pig?
A. Might get stuck if line size reduces
B. Need special connections to launch and retrieve the pig
C. Thickness readings are inaccurate
D. Difficult to go around typical elbows
C. Thickness readings are inaccurate
When excavating pipe for insepction, the:
A. Inspector must monitor the excavation
B. Last few inches should be dug up by hand
C. Minimum length to excavate is 25 feet
D. Best area to dig is the area where the highest soil resistivity
B. Last few inches should be dug up by hand
Guided wave UT may be used to inspect buried piping. One installation (equipment setup) may be able to screen:
A. 15 feet
B. 25 feet
C. 50 feet
D. 100 feet
A. 15 feet
What is the suggested interval for above grade visual surveillance on buried piping systems?
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 piping inspector
B. Piping engineer
C. Owner/user
D. Tank farm operation 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 year
B. 5 years
C. 10 years
D. 15 years
B. 5 years