3e451 Volume 2 Fuel Tank, Tank Entry And Operation And Maintenance Of Mechanical System Components
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Questions and Answers
- 1.
(201) What does the Defense Energy Support Center (DESC) determine the type, size, and number of fuel tanks needed at each base are?
- A.
Air Force standard design
- B.
The mission requirements
- C.
MAJCOM recommendations
- D.
Available construction dollars
Correct Answer
B. The mission requirementsExplanation
The Defense Energy Support Center (DESC) determines the type, size, and number of fuel tanks needed at each base based on the mission requirements. This means that the fuel tanks are chosen and designed based on the specific needs and objectives of the base's operations. The DESC takes into consideration factors such as the types of aircraft and vehicles that need fuel, the expected fuel consumption, and any specific operational considerations. By considering the mission requirements, the DESC ensures that each base has the appropriate fuel storage capacity to support its operations effectively.Rate this question:
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- 2.
(201) What will horizontal underground storage tanks and cut and cover tanks that issue jet fuel have on top of them?
- A.
A pumphouse
- B.
A concrete cover
- C.
An open air shed
- D.
Nothing, to prevent collapse of the tank
Correct Answer
A. A pumphouseExplanation
Horizontal underground storage tanks and cut and cover tanks that issue jet fuel will have a pumphouse on top of them. A pumphouse is necessary to house the pumps and equipment needed to transfer the jet fuel in and out of the tanks. It provides a controlled and secure environment for the operation of the pumps, ensuring the safe and efficient management of the fuel storage and distribution system.Rate this question:
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- 3.
(201) All new tanks must have what kind of containment?
- A.
Plastic liner
- B.
Leak detection
- C.
Concrete bottom
- D.
Double-wall construction or dyke
Correct Answer
D. Double-wall construction or dykeExplanation
Double-wall construction or dyke is the correct answer because it provides an additional layer of protection against leaks or spills. A double-wall construction consists of two walls, with the inner wall holding the tank contents and the outer wall acting as a secondary containment system. This design helps to prevent the escape of hazardous materials in case of a leak or rupture in the inner wall. A dyke, on the other hand, is a barrier or embankment built around the tank to contain any potential spills. Both options ensure that any leaks or spills are contained, minimizing the risk of environmental damage or harm to human health.Rate this question:
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- 4.
(201) What should you use when replacing a manway cover?
- A.
New nuts and bolts
- B.
The old gasket if it is in good condition
- C.
A new gasket slightly thicker than the old one
- D.
A new gasket the same thickness as the old one
Correct Answer
D. A new gasket the same thickness as the old oneExplanation
When replacing a manway cover, it is recommended to use a new gasket that is the same thickness as the old one. This ensures a proper seal and prevents any leaks or damage. Using a gasket of a different thickness may not provide the same level of sealing and could result in the cover not fitting properly. Therefore, it is important to use a new gasket that matches the thickness of the old one to maintain the integrity of the manway cover.Rate this question:
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- 5.
(201) Damage to a tank can occur if the
- A.
Vent or vent piping becomes clogged
- B.
Tank has an anti-rotation device
- C.
Low-level shutoff fails to work
- D.
High level alarm fails to work
Correct Answer
A. Vent or vent piping becomes cloggedExplanation
If the vent or vent piping becomes clogged, it can lead to damage to the tank. The vent is responsible for allowing air to enter and exit the tank as the liquid level changes. If the vent becomes blocked, pressure can build up inside the tank, potentially causing damage or even an explosion. Therefore, it is important to ensure that the vent and vent piping are clear and free from any obstructions to prevent any potential damage to the tank.Rate this question:
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- 6.
(202) What type of above ground tank can withstand very little pressure or vacuum during the filling or removal of fuel?
- A.
Vertical
- B.
Cone roof
- C.
Floating roof tank
- D.
Cone roof tank with floating pan
Correct Answer
B. Cone roofExplanation
A cone roof tank is designed to withstand very little pressure or vacuum during the filling or removal of fuel. The cone-shaped roof provides structural support and helps to distribute any pressure or vacuum evenly, preventing damage to the tank. This type of tank is commonly used for storing flammable liquids and is suitable for environments where there may be minimal pressure or vacuum fluctuations.Rate this question:
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- 7.
(202) The product withdrawal line terminate inside a cone roof with a floating pan in a
- A.
Vertical position, 6 inches above the top of the sump
- B.
Vertical position, 6 inches above the bottom of the sump
- C.
Horizontal position, 6 inches above the top of the sump
- D.
Horizontal position, 6 inches above the bottom of the sump
Correct Answer
A. Vertical position, 6 inches above the top of the sumpExplanation
The correct answer is "Vertical position, 6 inches above the top of the sump". This means that the product withdrawal line ends inside a cone roof with a floating pan, and it is positioned vertically 6 inches above the top of the sump. This positioning ensures that the line is above the sump, allowing for proper drainage and preventing any potential contamination or blockage in the sump.Rate this question:
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- 8.
(202) What size is the water draw off line in an all weather tank, and where does it terminate?
- A.
1/2 inch, 1/2 inch from the sump bottom
- B.
1/2 inch, 1 inch from the sump bottom
- C.
3/4 inch, 1/2 inch from the sump bottom
- D.
3/4 inch, 1 inch from the sump bottom
Correct Answer
C. 3/4 inch, 1/2 inch from the sump bottomExplanation
The water draw off line in an all weather tank is 3/4 inch in size. It terminates 1/2 inch from the sump bottom.Rate this question:
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- 9.
(202) In the northern hemisphere, which way will the inlet line on an all-weather tank cause the fuel to rotate, and what degree is the line turned?
- A.
Clock-wise, 45
- B.
Clock-wise, 60
- C.
Counter clock-wise, 45
- D.
Counter clock-wise, 60
Correct Answer
D. Counter clock-wise, 60Explanation
The correct answer is counter-clockwise, 60. In the northern hemisphere, the Coriolis effect causes fluids to rotate counterclockwise. This is due to the rotation of the Earth on its axis. The inlet line on an all-weather tank is designed to take advantage of this rotation and enhance the mixing and circulation of the fuel. The 60-degree turn of the line helps to further promote the counterclockwise rotation of the fuel.Rate this question:
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- 10.
(202) At what level does the high-level alarm actuate on a cone roof with a floating pan?
- A.
Just before the high-level shut-off level
- B.
Just after the high-level shut-off level
- C.
Just before the high-high level alarm
- D.
Just after the high-high level alarm
Correct Answer
A. Just before the high-level shut-off levelExplanation
The high-level alarm on a cone roof with a floating pan actuates just before the high-level shut-off level. This means that when the liquid level reaches the point just before the shut-off level, the alarm will be triggered to alert operators or control systems about the approaching high-level condition.Rate this question:
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- 11.
(202) What level above the tank bottom is the low-level shut-off set at on a 25,000 bbl cone roof tank with a floating pan?
- A.
18 inches
- B.
24 inches
- C.
27 inches
- D.
30 inches
Correct Answer
C. 27 inchesExplanation
The low-level shut-off on a 25,000 bbl cone roof tank with a floating pan is set at 27 inches above the tank bottom. This means that when the liquid level in the tank reaches 27 inches from the bottom, the shut-off mechanism will activate and stop the flow of liquid. This is an important safety measure to prevent the tank from running dry and potentially causing damage or accidents.Rate this question:
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- 12.
(202) At what level are the support legs on a cone roof tank with floating pan set at for day-to-day business?
- A.
1 1/2 feet
- B.
3 feet
- C.
4 1/2 feet
- D.
6 feet
Correct Answer
B. 3 feetExplanation
The support legs on a cone roof tank with a floating pan are set at a level of 3 feet for day-to-day business. This height provides stability and support for the tank and ensures that it remains in the desired position. It is important to maintain the correct level of support to prevent any accidents or damage to the tank and its contents.Rate this question:
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- 13.
(202) What type of vent is located on a floating pan?
- A.
Slot
- B.
Open
- C.
Bleeder
- D.
Overflow
Correct Answer
C. BleederExplanation
A bleeder vent is located on a floating pan. This type of vent allows excess pressure to escape from the pan, preventing any potential damage or malfunction. It helps to regulate the pressure inside the pan and maintain a safe operating environment.Rate this question:
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- 14.
(203) The wind girder is installed on floating roof tanks to
- A.
Keep the roof from rotating
- B.
Prevent the collapse of the tank shell
- C.
Provide a vapor recovery area under the roof
- D.
Provide a path to the ground for static electricity
Correct Answer
B. Prevent the collapse of the tank shellExplanation
The wind girder is installed on floating roof tanks to prevent the collapse of the tank shell. The wind girder provides additional support and stability to the tank shell, especially during strong winds or storms. Without the wind girder, the tank shell could potentially collapse under the external pressure caused by high winds, leading to a catastrophic failure of the tank. Therefore, the installation of the wind girder is crucial in ensuring the structural integrity and safety of the floating roof tank.Rate this question:
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- 15.
(203) The roof guide is installed on floating roof tanks to
- A.
Keep the roof from rotating
- B.
Prevent the collapse of the tank shell
- C.
Provide a vapor recovery area under the roof
- D.
Provide a path to the ground for static electricity
Correct Answer
A. Keep the roof from rotatingExplanation
The roof guide is installed on floating roof tanks to keep the roof from rotating. This is important because the roof of a floating roof tank floats on the liquid stored inside, and without proper guidance, it could rotate and cause damage to the tank or its components. The roof guide acts as a stabilizing mechanism, ensuring that the roof remains in a fixed position and does not rotate. This helps maintain the structural integrity of the tank and prevents any potential accidents or failures.Rate this question:
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- 16.
(203) The double-deck floating roof tank is the most efficient type of roof because the roof
- A.
Slopes to the center
- B.
Support legs are adjustable
- C.
Has insulating air space between the decks
- D.
Water drains easily towards the center
Correct Answer
C. Has insulating air space between the decksExplanation
The double-deck floating roof tank is the most efficient type of roof because it has insulating air space between the decks. This insulating air space helps to reduce the heat transfer between the stored liquid and the external environment, preventing evaporation and maintaining the temperature of the liquid. This insulation improves the efficiency of the tank by reducing energy loss and minimizing the need for additional heating or cooling.Rate this question:
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- 17.
(204) About how far above the tank floor is the first stage of the deep-well turbine pump located?
- A.
3 inches
- B.
6 inches
- C.
9 inches
- D.
12 inches
Correct Answer
B. 6 inchesExplanation
The first stage of the deep-well turbine pump is located about 6 inches above the tank floor.Rate this question:
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- 18.
(204) What size is the cleanout line on an underground tank, and where does it terminate outside the tank
- A.
1/2 inch, 6 inches above ground level
- B.
1/2 inch, 12 inches above ground level
- C.
3/4 inch, 6 inches above ground level
- D.
3/4 inch, 12 inches above ground level
Correct Answer
D. 3/4 inch, 12 inches above ground levelExplanation
The cleanout line on an underground tank is 3/4 inch in size and it terminates 12 inches above ground level.Rate this question:
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- 19.
(205) You must clean a bulk storage tank that has a receiving filter separator and is internally coated every
- A.
4 years
- B.
6 years
- C.
8 years
- D.
10 years
Correct Answer
C. 8 yearsExplanation
The correct answer is 8 years. This is because the bulk storage tank is internally coated, which helps to protect the tank from corrosion and other damage. However, over time, the coating may deteriorate and become less effective. Therefore, it is recommended to clean the tank every 8 years to remove any buildup or debris that may have accumulated and to ensure that the coating remains intact and functional. Cleaning the tank at regular intervals helps to maintain its integrity and prolong its lifespan.Rate this question:
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- 20.
(205) You must clean an operating storage tank that does not have a receiving filter separator but has internal coating every
- A.
4 years
- B.
6 years
- C.
8 years
- D.
10 years
Correct Answer
B. 6 yearsExplanation
The correct answer is 6 years. The internal coating of the operating storage tank needs to be cleaned every 6 years.Rate this question:
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- 21.
(205) You must clean an operating tank that is not internally coated and does not have a receiving filter separator every
- A.
4 years
- B.
6 years
- C.
8 years
- D.
10 years
Correct Answer
A. 4 yearsExplanation
The operating tank must be cleaned every 4 years because it is not internally coated and does not have a receiving filter separator. Without an internal coating, the tank is more susceptible to corrosion and buildup of contaminants. Additionally, the absence of a receiving filter separator means that any impurities in the incoming fluid will directly enter the tank, further increasing the need for regular cleaning. Cleaning the tank every 4 years ensures that it remains free from excessive corrosion and contamination.Rate this question:
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- 22.
(205) How often do you clean a Mogas or diesel tank?
- A.
4 years
- B.
6 years
- C.
8 years
- D.
By direction of the fuels management office
Correct Answer
D. By direction of the fuels management officeExplanation
The frequency of cleaning a Mogas or diesel tank is determined by the fuels management office. They provide directions on when the tank should be cleaned, which can vary depending on factors such as usage, environmental conditions, and maintenance requirements.Rate this question:
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- 23.
(205) How is the product identification displayed on an aboveground tank?
- A.
Yellow bands with white letters on a black background
- B.
Yellow bands with black letters on a white background
- C.
Black bands with white letters on a yellow background
- D.
Black bands with yellow letters on a white background
Correct Answer
A. Yellow bands with white letters on a black backgroundExplanation
The product identification on an aboveground tank is displayed using yellow bands with white letters on a black background. This color combination provides high visibility and contrast, making it easier to read and identify the product stored in the tank. The yellow bands stand out against the black background, and the white letters are easily readable on the dark surface. This color scheme is commonly used for safety and regulatory purposes to ensure that the product information is clearly visible and identifiable.Rate this question:
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- 24.
(206) The fuse link on a fuse link valve used on a cone roof tank will normallymelt at what temperature?
- A.
160
- B.
180
- C.
200
- D.
220
Correct Answer
A. 160Explanation
The fuse link on a fuse link valve used on a cone roof tank will normally melt at a temperature of 160 degrees.Rate this question:
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- 25.
(206) When manually gauging a tank, why must you keep the tape in contact with the gauge pipe?
- A.
To keep the tape from twisting
- B.
To easily read the tape increments
- C.
To prevent the discharge of a spark
- D.
To steady the tape when lowering the bob
Correct Answer
C. To prevent the discharge of a sparkExplanation
Keeping the tape in contact with the gauge pipe helps to prevent the discharge of a spark. This is important because tanks often contain flammable or combustible materials. If a spark were to occur during the gauging process, it could potentially ignite the contents of the tank and cause a fire or explosion. Therefore, maintaining contact between the tape and the gauge pipe reduces the risk of sparking and helps to ensure safety during the gauging process.Rate this question:
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- 26.
(207) When the roof supports on a floating roof tank are in the UP position, at what level will the roof rest above the floor?
- A.
3 feet
- B.
4 feet
- C.
5 feet
- D.
6 feet
Correct Answer
A. 3 feetExplanation
When the roof supports on a floating roof tank are in the UP position, the roof will rest 3 feet above the floor.Rate this question:
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- 27.
(207) What prevents fuel from entering a roof drain line?
- A.
Flange gaskets and Teflon® ring packing
- B.
Flange gaskets and asbestos ring packing
- C.
Threaded gaskets and Teflon® ring packing
- D.
Threaded gaskets and asbestos ring packing
Correct Answer
B. Flange gaskets and asbestos ring packingExplanation
Flange gaskets and asbestos ring packing prevent fuel from entering a roof drain line. These materials create a tight seal between the flange and the drain line, preventing any leakage or seepage of fuel. Asbestos ring packing is known for its durability and resistance to chemical substances, making it an effective barrier against fuel.Rate this question:
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- 28.
(207) At what level must the automatic bleeder vent supports be set when preparing for an internal inspection and cleaning?
- A.
3 feet
- B.
4 feet
- C.
5 feet
- D.
6 feet
Correct Answer
D. 6 feetExplanation
The automatic bleeder vent supports must be set at 6 feet when preparing for an internal inspection and cleaning. This height ensures that the vent supports are positioned high enough to allow for proper venting and release of any trapped air or gases during the inspection and cleaning process. Setting the vent supports at this level helps to maintain the safety and efficiency of the system.Rate this question:
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- 29.
(207) In extremely cold climates, what should you do to the roof drain line?
- A.
Fill it with salt water
- B.
Fill it with antifreeze only
- C.
Fill it with 10 SAE weight oil
- D.
Fill it with a 50/50 mix of antifreeze and water
Correct Answer
D. Fill it with a 50/50 mix of antifreeze and waterExplanation
In extremely cold climates, filling the roof drain line with a 50/50 mix of antifreeze and water is the correct answer. This mixture helps to prevent the water in the drain line from freezing and causing blockages or damage to the roof. Antifreeze lowers the freezing point of the water, ensuring that it remains in a liquid state even in very low temperatures. By using a 50/50 mix, the antifreeze concentration is sufficient to prevent freezing while still allowing for proper drainage. This solution is more effective than filling the drain line with salt water, antifreeze only, or 10 SAE weight oil.Rate this question:
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- 30.
(207) What is the inspection frequency for the fabric seal on a floating roof tank?
- A.
Weekly
- B.
Monthly
- C.
Semi-annual
- D.
Annually
Correct Answer
B. MonthlyExplanation
The fabric seal on a floating roof tank needs to be inspected on a monthly basis. Regular inspections are necessary to ensure the integrity and effectiveness of the seal, which helps prevent leaks and contamination. Monthly inspections allow for timely identification and resolution of any issues or deterioration in the fabric seal, helping to maintain the safety and efficiency of the tank.Rate this question:
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- 31.
(207) When filling the tank to check the high-high-level alarm, what must be disabled?
- A.
The high-level alarm
- B.
The low-level switch
- C.
The low-level shut-off valve
- D.
The high-level shut-off valve
Correct Answer
D. The high-level shut-off valveExplanation
When filling the tank to check the high-high-level alarm, the high-level shut-off valve must be disabled. This is because the high-level shut-off valve is responsible for stopping the flow of liquid into the tank when it reaches a certain level. By disabling the high-level shut-off valve, it ensures that the tank can be filled completely without triggering the shut-off mechanism prematurely. This allows for an accurate test of the high-high-level alarm to be conducted.Rate this question:
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- 32.
(208) What would you use to check the liquidometer accuracy?
- A.
Tape and bob
- B.
Liquid level float
- C.
Liquid level gauge
- D.
Weighted gauge tester
Correct Answer
A. Tape and bobExplanation
To check the accuracy of a liquidometer, one would use a tape and bob. A tape and bob is a measuring tool that consists of a tape measure and a weighted bob attached to the end. The bob is lowered into the liquid to measure the depth or level accurately. This method allows for precise measurement and ensures the liquidometer's accuracy.Rate this question:
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- 33.
(208) How would you take care of internal corrosion for the low-level control attached to the liquidometer?
- A.
Wire brush clean and replace the cover gasket
- B.
Wire brush clean and replace the cover
- C.
Air it out and replace the cover gasket
- D.
Air it out and replace the cover
Correct Answer
A. Wire brush clean and replace the cover gasketExplanation
To take care of internal corrosion for the low-level control attached to the liquidometer, the correct approach is to wire brush clean the internal components and then replace the cover gasket. This process helps remove any corrosion buildup on the internal parts and ensures a proper seal by replacing the gasket. It is important to clean and maintain the control regularly to prevent corrosion and ensure accurate readings from the liquidometer.Rate this question:
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- 34.
(209) Who will assign a qualified tank entry supervisor to supervise a tank cleaning operation?
- A.
Shop supervisor
- B.
Section superintendent
- C.
Base safety
- D.
MAJCOM fuels engineer
Correct Answer
D. MAJCOM fuels engineerExplanation
The MAJCOM fuels engineer will assign a qualified tank entry supervisor to supervise a tank cleaning operation. This is because the MAJCOM fuels engineer is responsible for overseeing fuel operations and safety procedures within the command. As part of their role, they have the authority to ensure that qualified individuals are assigned to supervise specific tasks, such as tank cleaning operations, to maintain safety standards and prevent any potential hazards.Rate this question:
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- 35.
(209) How long before entering a fuel tank must you request permission from your MAJCOM?
- A.
10 days
- B.
15 days
- C.
10 workdays
- D.
15 workdays
Correct Answer
D. 15 workdaysExplanation
Before entering a fuel tank, it is necessary to request permission from the MAJCOM. The correct answer is 15 workdays. This means that the request must be made at least 15 workdays in advance before entering the fuel tank. This allows sufficient time for the MAJCOM to review and approve the request, ensuring proper coordination and safety measures are in place before entering the fuel tank.Rate this question:
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- 36.
(209) Which one of the following is not the responsibility of the MAJCOM fuels engineer’s representative during the contract cleaning of a fuel tank?
- A.
To inspect the contractors equipment
- B.
To advise the contractors of known potential hazards
- C.
To stop the contractors work for contract violations
- D.
To act as the quality assurance evaluator pertaining to the work
Correct Answer
C. To stop the contractors work for contract violationsExplanation
The MAJCOM fuels engineer's representative is responsible for several tasks during the contract cleaning of a fuel tank. These include inspecting the contractors' equipment, advising them of known potential hazards, and acting as the quality assurance evaluator pertaining to the work. However, it is not their responsibility to stop the contractors' work for contract violations.Rate this question:
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- 37.
(210) Which of the following fuels normally contains a higher concentration of benzene?
- A.
JP-4
- B.
JP-8
- C.
Diesel
- D.
Gasoline
Correct Answer
D. GasolineExplanation
Gasoline normally contains a higher concentration of benzene compared to the other fuels listed. Benzene is a chemical compound that is commonly found in gasoline as an additive. It is used to enhance the octane rating of gasoline and improve engine performance. However, benzene is a known carcinogen and exposure to high levels of benzene can have harmful health effects. Therefore, regulations have been implemented to limit the amount of benzene in gasoline to ensure safety and reduce environmental pollution.Rate this question:
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- 38.
(211) During tank cleaning, when should you remove heavily contaminated clothing?
- A.
Immediately, after leaving the area
- B.
After being drenched with water
- C.
At the end of the day, after leaving the area
- D.
At the end of the day, after being drenched with water
Correct Answer
A. Immediately, after leaving the areaExplanation
During tank cleaning, it is important to remove heavily contaminated clothing immediately after leaving the area. This is because contaminated clothing can pose a risk of spreading harmful substances or chemicals to other areas or individuals. By removing the clothing immediately, the risk of contamination is minimized, ensuring the safety of both the person wearing the clothing and those around them.Rate this question:
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- 39.
(211) Communication gear must be used during the cleaning of an underground JP–8 tank when the
- A.
Tank capacity is 10,000 gallons
- B.
Tank capacity is 25,000 gallons
- C.
Manhole access is 6 feet below ground level
- D.
Manhole access is 12 feet below ground level
Correct Answer
D. Manhole access is 12 feet below ground level -
- 40.
(211) All electrical equipment to be used within 50 feet of any fuel system must be defined as which class in the National Electrical Code?
- A.
Class 1, Division 1, Group C
- B.
Class 1, Division 1, Group D
- C.
Class 1, Division 2, Group C
- D.
Class 1, Division 2, Group D
Correct Answer
A. Class 1, Division 1, Group CExplanation
Electrical equipment that is to be used within 50 feet of any fuel system must be defined as Class 1, Division 1, Group C according to the National Electrical Code. This classification ensures that the equipment is suitable for use in hazardous locations where flammable gases or vapors may be present. Class 1 refers to the presence of flammable gases or vapors, Division 1 indicates that the hazardous conditions are expected to be present during normal operations, and Group C specifies the specific type of flammable material that may be present.Rate this question:
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- 41.
(211) A safety harness, used in tank cleaning, is good for a maximum of how many years from the date stamped on the harness?
- A.
5
- B.
10
- C.
15
- D.
20
Correct Answer
B. 10Explanation
A safety harness used in tank cleaning is good for a maximum of 10 years from the date stamped on the harness. This means that after 10 years, the harness may no longer be safe or reliable to use. Regular inspection and replacement of the harness is necessary to ensure the safety of the user.Rate this question:
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- 42.
(212) Artificial lights, other than battery-powered safety lanterns, can be used only during tank cleaning after what condition is met?
- A.
The tank cleaning supervisor has made their initial entry
- B.
The LEL inside the tank is below 20 percent
- C.
The tank has been washed down
- D.
The tank is vapor free
Correct Answer
D. The tank is vapor freeExplanation
Artificial lights can only be used during tank cleaning after the tank is vapor free. This is because artificial lights can pose a fire hazard in the presence of vapors. Therefore, it is important to ensure that the tank is free from any flammable vapors before using artificial lights during the cleaning process.Rate this question:
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- 43.
(212) During initial cleaning, at what percent of the lower explosive limit (LEL) must you suspend washing down a tank?
- A.
10
- B.
20
- C.
30
- D.
40
Correct Answer
B. 20Explanation
During the initial cleaning of a tank, you must suspend washing down the tank when the concentration of the flammable vapor in the tank reaches 20% of the lower explosive limit (LEL). This is important to prevent any potential ignition or explosion hazards that may occur if the concentration of flammable vapor exceeds this threshold.Rate this question:
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- 44.
(212) At what vapor level may workers initially enter a tank for tank cleaning?
- A.
Below 10 percent LEL
- B.
Below 20 percent LEL
- C.
Below 40 percent LEL
- D.
Below 50 percent LEL
Correct Answer
A. Below 10 percent LELExplanation
Workers may initially enter a tank for tank cleaning when the vapor level is below 10 percent LEL. This is because the Lower Explosive Limit (LEL) represents the minimum concentration of a flammable substance in the air that can potentially ignite. To ensure safety, workers should enter the tank when the vapor level is below this threshold to minimize the risk of an explosion or fire hazard.Rate this question:
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- 45.
(212) During tank cleaning, how often must you record a vapor reading?
- A.
Every 10 minutes
- B.
Every 15 minutes
- C.
At the beginning of the tank cleaning
- D.
At the beginning and end of the tank cleaning
Correct Answer
B. Every 15 minutesExplanation
During tank cleaning, it is necessary to record a vapor reading every 15 minutes. This is important to ensure that the tank is being properly cleaned and that any potentially hazardous vapors are being monitored. Regular vapor readings help to ensure the safety of the cleaning process and can alert the crew to any potential issues or hazards that may arise during the cleaning operation.Rate this question:
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- 46.
(212) When can people enter a fuel tank without protective equipment?
- A.
0 percent LEL only
- B.
0 percent LEL and the tank has been washed out and dried
- C.
0 percent LEL, the tank has been washed out and dried, the tank is known never to have contained leaded fuel, and the Bioenvironmental Engineer has approved their entry
- D.
Never
Correct Answer
D. Never -
- 47.
(213) What must be done to fuel pumps and motors located in a pit if they are to be abandoned?
- A.
Drained only
- B.
Drained and capped off
- C.
Remove, capped off and oiled
- D.
Removed and stored in a dry place
Correct Answer
D. Removed and stored in a dry placeExplanation
To properly abandon fuel pumps and motors located in a pit, they must be removed from the pit and stored in a dry place. This ensures that they are not left in a potentially hazardous or deteriorating environment. Simply draining them or capping them off would not be sufficient for proper abandonment.Rate this question:
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- 48.
(213) What must be done to meters in a pit that is to be abandoned?
- A.
Drained only
- B.
Drained and capped off
- C.
Drained, capped off and oiled
- D.
Drained, removed, oiled, and placed in storage
Correct Answer
D. Drained, removed, oiled, and placed in storageExplanation
To ensure proper abandonment of a pit, the meters must be drained, removed, oiled, and placed in storage. Draining the meters is necessary to remove any remaining fluids. Removing the meters from the pit ensures that they are not left behind and can be properly maintained. Oiling the meters helps to protect them from corrosion while in storage. Finally, placing the meters in storage ensures they are safely stored until needed again.Rate this question:
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- 49.
(214) How do you reset the lower explosive limit (LEL) sensor on the MultiRAE PGM–50?
- A.
Press the "reset" button
- B.
Sample fresh air for 60 seconds then press the "Y/+" button
- C.
Turn the unit off then back on
- D.
PMEL must replace the sensor
Correct Answer
B. Sample fresh air for 60 seconds then press the "Y/+" buttonExplanation
To reset the lower explosive limit (LEL) sensor on the MultiRAE PGM-50, you need to sample fresh air for 60 seconds and then press the "Y/+" button. This process allows the sensor to recalibrate and ensure accurate readings. Pressing the "reset" button or turning the unit off and back on will not reset the LEL sensor. If the sensor is not functioning properly, it must be replaced by PMEL.Rate this question:
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- 50.
(214) What is the minimum recommended voltage for the MultiRAE PGM–50?
- A.
4.2 Volts
- B.
4.4 Volts
- C.
4.8 Volts
- D.
5.2 Volts
Correct Answer
C. 4.8 VoltsExplanation
The minimum recommended voltage for the MultiRAE PGM-50 is 4.8 Volts. This means that the device requires a minimum voltage of 4.8 Volts to function properly. Using a lower voltage may result in the device not working correctly or not working at all. It is important to ensure that the device is powered with the minimum recommended voltage to avoid any issues or malfunctions.Rate this question:
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Current Version
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Mar 20, 2023Quiz Edited by
ProProfs Editorial Team -
Aug 17, 2013Quiz Created by
Pggomoljak328
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