3e451 Volume 2 Fuel Tank, Tank Entry and Operation and Maintenance Of Mechanical System Components

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.

Emergency-stop switches are typically colored red because red is universally recognized as a signal for danger or stop. This color is chosen to ensure that the switch stands out and can be easily identified in emergency situations. Red is a highly visible color that can quickly alert individuals to the location of the emergency-stop switch, allowing them to quickly and effectively stop machinery or equipment in case of an emergency.

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.

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.

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.

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.

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.

JP-8 fuel is identified using three bands.

When an A. O. Smith meter requires major maintenance, the repairs should be done by the manufacturer. This is because the manufacturer is the one who has the expertise and knowledge about the specific design and workings of the meter. They would have the necessary tools, parts, and technical skills to carry out the repairs effectively and ensure that the meter is functioning correctly. The manufacturer would also have access to any necessary software updates or technical support that may be required during the maintenance process. Therefore, it is best to rely on the manufacturer for major repairs of an A. O. Smith meter.

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.

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.

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.

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.

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.

Air in the line is the most probable cause for a meter to over-register. When there is air in the line, it can cause the meter to inaccurately measure the flow of the substance being measured. This is because the air can create turbulence or bubbles that interfere with the proper functioning of the meter, leading to an overestimation of the quantity being measured.

Electrical controls in hazardous areas must be protected against explosion. This is because hazardous areas are prone to the presence of flammable substances, such as gases or vapors, which can ignite and cause an explosion if they come into contact with an electrical spark or heat source. Therefore, it is crucial to have explosion-proof electrical controls in these areas to prevent any potential ignition sources from causing a catastrophic explosion.

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.

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.

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.

To ensure safe dispersal of fuel vapors, a storage tank vent pipe must extend at least 12 feet high. This height allows the vapors to disperse effectively and reduces the risk of ignition or explosion. A higher vent pipe also helps to prevent the vapors from accumulating near the ground or any potential ignition sources. Therefore, extending the vent pipe to a height of 12 feet is necessary for the safe operation of the storage tank.

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.

The correct answer is 6 years. The internal coating of the operating storage tank needs to be cleaned every 6 years.

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.

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.

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.

Normally, one storage tank would be used for each product (MOGAS and diesel fuel) at an automotive service station. This is because separate storage tanks are needed to store and dispense different types of fuel to ensure proper handling and prevent contamination. Having one storage tank for each product allows for efficient management and distribution of fuel at the service station.

The minimum speed for a scraper when cleaning a pipeline is 2 mph. This speed is necessary to ensure that the scraper effectively removes debris and build-up from the pipeline. A slower speed may not provide enough force to properly clean the pipeline, while a higher speed could potentially damage the pipeline or the scraper itself. Therefore, a speed of 2 mph strikes a balance between effectiveness and safety in pipeline cleaning.

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.

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.

The correct answer is O-ring. Leakage inside the back of a liquid control meter is often caused by a faulty O-ring. O-rings are used as seals in many applications, including liquid control meters, to prevent leakage. If the O-ring is damaged or worn out, it can no longer effectively seal the meter, leading to leakage.

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.

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.

When the float of the pilot valve assembly is in the TOP position, the rotary disc will change positions and the pressure will be directed to the fuel discharge valve.

Teflon vane inserts maintain a tight seal in the measuring chamber of an A. O. Smith meter. These inserts are made of Teflon, a non-stick and high-performance material. The Teflon vane inserts create a seal between the moving parts of the meter, preventing any leakage or loss of pressure. This ensures accurate measurement and prevents any outside factors from interfering with the readings.

The first stage of the deep-well turbine pump is located about 6 inches above the tank floor.

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.

To match the actual fuel dispensed through the meter, the gear train ratio needs to be changed. The gear train ratio determines the relationship between the rotation of the meter and the display on the register. By adjusting the gear train ratio, the register can accurately reflect the amount of fuel dispensed. Resetting the register head, replacing or cleaning the register counter may not address the issue of matching the actual fuel dispensed, as they do not directly affect the gear train ratio.

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.

When the float in a vertical filter separator rises to the top position, the fuel discharge valve closes. This is because the float rising indicates that the fuel has reached the desired level in the separator. Closing the fuel discharge valve prevents any further fuel from being discharged and ensures that the fuel remains in the separator for further processing or distribution.

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.

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.

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.

If the meter register on a dispenser does not reset to zero or the numerical wheels do not turn during delivery, the probable cause is a broken shear pin. A shear pin is designed to break under excessive force or stress, preventing damage to other components. In this case, the broken shear pin would prevent the meter register from resetting to zero or the numerical wheels from turning, indicating a malfunction in the dispenser.

A master meter has 2 hoses connected on the outlet side.

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.

When the water drain valve is removed from the filter separator, the control tubing that once went to the water drain cover chamber is rerouted nowhere. It is plugged off, meaning it is closed or sealed to prevent any flow or passage of fluid.

The emergency-stop switches have closed contacts, which means that the circuit is completed when the switch is activated. These closed contacts are used for low-voltage control of the fuel transfer pump. This means that when the emergency-stop switch is pressed, it allows low-voltage power to flow through the circuit and control the fuel transfer pump.

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.

A foot valve is a type of valve that is found on the suction line inside the tank if the fuel dispensing units are self-contained. This valve is designed to prevent fuel from flowing back into the tank when the dispenser is not in use. It allows fuel to flow in only one direction, from the tank to the dispenser, ensuring that the fuel is always ready for dispensing.

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.