Section 9 – Leak Testing Flashcards
Which of the following is not a RPB (release prevention barrier)?
A. Concrete reinforced pad
B. Double bottom tank
C. Effective bottom side CP
D. Under-tank liner (yes a diaper!)
C (9.1.1)
Which of the following is not a leak detection technology (Open Book)?
A. Acoustic Emission leak detection
B. Capillary Soil leak detection
C. Mass Balancing
D. Tracer Gas injected under the tank bottom
B (9.1.2 - Fig 58)
Advance leak detection systems are described in (Open Book):
A. API 334.
B. API 445.
C. API 650 Appendix H.
D. API 2201.
A (9.1.3)
Tank Hydraulic Integrity:
A. today should be achieved by building new tanks with a double bottom.
B. can only be assured if CP has been installed.
C. means the tank has not settled in a swampy area.
D. is just a fancy way to say “the tank is not leaking”.
D (9.1.4)
When visual inspection is performed, the inspector’s eyes should be within:
A. 12 inches of the surface to be examined.
B. 24 inches of the surface to be examined.
C. 36 inches of the surface to be examined.
D. as close as the inspector’s truck can get to the surface to be examined.
B (9.2.1)
When visual inspection is performed, the inspector’s eyes should look relatively straight-on to the surface. The inspector’s eyes should not be at an angle that is:
A. < 10 degrees.
B. < 30 degrees.
C. < 45 degrees.
D. < 60 degrees.
B (9.2.1)
When visual inspection is performed, the amount of light needed for general viewing should be at least:
A. 15 foot-candles.
B. 30 foot-candles.
C. 50 foot-candles.
D. 100 foot-candles.
A (9.2.1)
When visual inspection is performed, the amount of light needed for inspecting small anomalies should be at least:
A. 15 foot-candles.
B. 30 foot-candles.
C. 50 foot-candles.
D. 100 foot-candles.
C (9.2.1)
A high-penetrating oil is used to check the initial weld pass on one side of the bottom-to-shell weld. The minimum dwell time for this wicking test is:
A. 10 minutes.
B. 1 hour.
C. 4 hours.
D. 24 hours.
C (9.2.2)
A tank floor is tested with a type of Bubble Test examination. In this test, an indicator solution is sprayed on the top-side of the floor and low-pressure air is added under the floor. The air pressure for this test should not exceed:
A. 1 inch of water.
B. 3 inches of water.
C. 2.5 psig.
D. 15 psig.
E. 750 mm of mercury.
B (9.2.3)
A tank floor is tested with another type of Bubble Test examination. In this test, about 6” of water is added inside the tank and low-pressure air is added under the floor. The air pressure for this test should not exceed:
A. 1 inch of water.
B. 3 inches of water.
C. 9 inches of water.
D. 2.5 psig.
E. 1250 mm of mercury.
C (9.2.3)
The effectiveness of a tank floor Bubble Test can be improved by:
A. increasing the pressure.
B. increasing the duration of the examination.
C. tapping the entire bottom with an air operated hammer.
D. pulsating the air pressure.
C (9.2.3)
Another variation of the Bubble Test examination is to build a clay dam around the tank and add water under the tank. (this is basically a “Reverse Hydro”) The height of the water in the dam must be at least:
A. 6 inches above the highest point in the floor.
B. 12 inches above the highest point in the floor.
C. 24 inches above the highest point in the floor.
D. 36 inches above the highest point in the floor (Anchors away !!!).
A (9.2.3)
When performing a Magnetic Particle examination on a tank:
A. the examiner must be qualified to ASNT standards.
B. the needed light intensity is 15 foot-candles.
C. the examination must include the weld and 6” on each side of the weld.
D. discontinuities are most evident near the weld surface.
D (9.2.6)
When performing a Magnetic Particle examination, discontinuities are most evident:
A. in stainless steels.
B. when the discontinuity is perpendicular to the magnetic flux.
C. when the discontinuity is parallel to the magnetic flux.
D. when the discontinuity is subsurface.
B (9.2.6)
What is one of the advantages of testing the tank floor with a tracer gas injected under the floor?
A. Any needed weld repairs can be made immediately
B. This technique is inexpensive
C. This technique can be used either with the tank in-service or out-of-service
D. Useful technique if the water table is extremely high
A (9.2.7.1)
One method to test a tank floor is to inject an inert gas on the bottom-side of the tank floor and use a gas detector on the top-side. A common gas for this test is:
A. Argon.
B. Carbon dioxide.
C. Helium.
D. Hydrogen Sulfide.
C (9.2.7.1)
A special leak detection method is called Volumetric Technology. The key measurements in this technology are:
A. Liquid Level and Pressure.
B. Liquid Level and Temperature.
C. Pressure and Mass.
D. Mass and Temperature.
B (9.3.2.1)
Another special leak detection method is called Mass Balancing Technology. The key measurement in this technology is:
A. Liquid Level.
B. Temperature.
C. Pressure.
D. Specific Gravity
C (9.3.2.2)
Another leak detection method is called the Chemical Marker Technology. Which of following best describe this method?
A. Chemical is added below the floor and chemical detection tools are used inside the tank.
B. A colored chemical is added below the tank and visual examination is performed on the top-side to find bleed-through.
C. Chemical is sprayed on the top-side of the tank, and detectors tubes are spaced on the bottom-side for air sampling.
D. Chemical is added to either the hydrotest water, or the tank’s product. Detectors tubes are spaced on the bottom-side for air sampling.
D (9.3.3.2)
When the Chemical Marker Technology is used, the typical inoculation concentration is:
A. 1 to 10 parts per million.
B. 40 to 125 parts per million.
C. 0.5%.
D. 1.0%.
A (9.3.3.3)
With Chemical Marker Technology, every part of the bottom should be within (Open Book):
A. 3 feet from a detection tube.
B. 10 feet from a detection tube.
C. 20 feet from a detection tube.
D. 32 feet from a detection tube.
C (9.3.3.5)
Acoustic Emission (AE) can also be used to determine if a tank floor is leaking. AE is based upon:
A. detection of leaking tracer chemical.
B. hearing sound from a leak.
C. measuring slight changes in liquid height.
D. using ultrasonic sound to find the leak.
B (9.3.4.1)
Acoustic Emission (AE) is being used to check for a tank leak. If a number of sensors are used then:
A. the exact location of a leak can be determined.
B. only the general area of a leak can be determined.
C. there is a 100% confidence level that any leaks will be found.
D. any noise detected by all sensors is a leak.
B (9.3.4.1)
