Stationary Engineer Practice Quiz

By Mike Jewel
Mike Jewel, Stationary Engineer
Mike, a state and municipally licensed steam and stationary engineer, boasts over 20 years of experience in building trades. His expertise reflects a seasoned professional dedicated to his craft.
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, Stationary Engineer
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Questions: 190 | Attempts: 21,202

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Stationary Engineer Practice Quiz - Quiz

Do you wish to be a Stationary Engineer? Get ready to take this quiz on Stationary Engineer Class 3 Examination that is here for you. A compendium of questions that should help with any licensing exam. This quiz is going to be educational and interesting as well at the same time. Would you be able to get a score above 70 on this quiz? You are an expert if you are able to do so. Let's see how well you perform. Best of luck to you!


Questions and Answers
  • 1. 

    1. The lowest visible water level in the gauge glass is ___ above the top of the boiler tubes on a scotch marine boiler.

    • A.

      2"

    • B.

      3"

    • C.

      12"

    • D.

      6"

    Correct Answer
    A. 2"
    Explanation
    The lowest visible water level in the gauge glass is 2" above the top of the boiler tubes on a scotch marine boiler. This is important because it ensures that there is enough water in the boiler to prevent overheating and damage to the tubes. It also allows for proper monitoring and maintenance of the water level in the boiler.

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  • 2. 

    1. The three classes of feedwater pumps are _______________, _______________, and _____________.

    • A.

      Reciprocating, centrifugal, and rotary

    • B.

      Reciprocating, centrifugal, and screw

    • C.

      Reciprocating, scroll, and centrifugal

    • D.

      Positive displacement, reciprocating, and centrifugal

    Correct Answer
    A. Reciprocating, centrifugal, and rotary
    Explanation
    The correct answer is "reciprocating, centrifugal, and rotary". These three classes refer to different types of feedwater pumps. Reciprocating pumps use a piston or plunger to create pressure and move the fluid. Centrifugal pumps use centrifugal force to move the fluid and are commonly used in industrial applications. Rotary pumps use rotating mechanisms to move the fluid, such as gears or vanes. Therefore, the correct answer includes all three types of pumps.

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  • 3. 

    1. The minimum size for the connection in between the gauge glass and the water column is _____.

    • A.

      3/8"

    • B.

      3/4"

    • C.

      1/2"

    • D.

      1/4"

    Correct Answer
    C. 1/2"
    Explanation
    The minimum size for the connection between the gauge glass and the water column is 1/2". This means that the diameter of the connection should be half an inch. It is important to have a proper size for the connection to ensure that there is adequate flow of water between the gauge glass and the water column. Having a smaller size could restrict the flow, while a larger size may lead to leakage or improper readings. Therefore, 1/2" is the correct minimum size for the connection.

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  • 4. 

    1. _____________ is the replacement for refrigerant R-22.

    • A.

      R-410a

    • B.

      R-134a

    • C.

      R-401a

    • D.

      R-123

    Correct Answer
    A. R-410a
    Explanation
    R-410a is the replacement for refrigerant R-22. Refrigerant R-22 is being phased out due to its harmful effects on the ozone layer. R-410a is a more environmentally friendly alternative that does not contribute to ozone depletion. It is commonly used in air conditioning systems as a refrigerant.

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  • 5. 

    1. A refrigerant system using R-134a is running at 148 psi on the discharge and 16psi on the suction. What is the compression ratio of the compression?

    • A.

      9.2:1

    • B.

      5.3:1

    • C.

      10:1

    • D.

      8:1

    Correct Answer
    B. 5.3:1
    Explanation
    The compression ratio (CR) of a refrigeration or compression system is calculated by dividing the absolute discharge pressure (P2) by the absolute suction pressure (P1):

    CR = P2 / P1

    In this case, you provided the pressures in psi, but to calculate the compression ratio, we need to convert them to absolute pressures in psi (psia). Absolute pressure is the sum of the gauge pressure and atmospheric pressure (14.7 psi at sea level).

    Absolute discharge pressure (P2) = 148 psi + 14.7 psi = 162.7 psi
    Absolute suction pressure (P1) = 16 psi + 14.7 psi = 30.7 psi

    Now, we can calculate the compression ratio:

    CR = P2 / P1
    CR = 162.7 psi / 30.7 psi

    CR ≈ 5.3

    So, the compression ratio of the refrigerant system is approximately 5.3:1.

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  • 6. 

    1. When using a lift lever to manually test a safety valve, the boiler pressure must be at least _____ percent of the safety valve setpoint.

    • A.

      80

    • B.

      75

    • C.

      70

    • D.

      90

    Correct Answer
    B. 75
    Explanation
    When using a lift lever to manually test a safety valve, the boiler pressure must be at least 75 percent of the safety valve setpoint. This is because the lift lever test is performed to ensure that the safety valve is functioning properly and can relieve excess pressure in the boiler. By testing at 75 percent of the setpoint, it ensures that the safety valve will open and relieve pressure when it reaches the setpoint, providing a safety measure for the boiler system.

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  • 7. 

    1. Unlike an infrared scanner, the ultraviolet scanner is no affected by the light given off by hot _________________.

    • A.

      Flames

    • B.

      Plasma

    • C.

      Refractories

    • D.

      Gasses of combustions

    Correct Answer
    C. Refractories
    Explanation
    An ultraviolet scanner is not affected by the light given off by hot refractories. Refractories are heat-resistant materials used in high-temperature industrial processes, such as furnaces. Infrared scanners rely on detecting the heat emitted by objects, including refractories, whereas ultraviolet scanners use ultraviolet light to detect and analyze different materials. Therefore, the ultraviolet scanner is not affected by the light emitted by hot refractories.

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  • 8. 

    1. The _________ __________ and _____________ _________ _______ sense heat to prove flame in the boiler.

    • A.

      Stack switch and rectifying flame rod

    • B.

      Flue sensor, infra red sensor

    • C.

      Stack switch, and infrared sensor

    • D.

      Flue sensor, rectifying flame rod

    Correct Answer
    A. Stack switch and rectifying flame rod
    Explanation
    The stack switch and rectifying flame rod are used to sense heat and prove flame in the boiler. The stack switch is a device that detects the temperature in the flue gas stack, while the rectifying flame rod is a sensor that detects the presence of a flame by measuring the electrical current generated by the flame. Together, these two components provide a reliable method for monitoring and ensuring the presence of a flame in the boiler.

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  • 9. 

    1. A _______________ ____________ air handler unit operates at the rated capacity at all times.

    • A.

      Variable Volume

    • B.

      Constant Volume

    • C.

      Single Zone

    • D.

      Multi-Zone

    Correct Answer
    B. Constant Volume
    Explanation
    A constant volume air handler unit operates at the rated capacity at all times, meaning that it consistently delivers a fixed volume of air. This type of air handler unit is typically used in buildings where the air conditioning or heating requirements do not vary significantly throughout the day or year. The unit's fan runs at a constant speed, providing a consistent airflow and temperature to the space it serves. This design is often more energy-efficient and easier to control compared to variable volume air handler units, which can adjust their airflow based on demand.

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  • 10. 

    1. If a bulge in a boiler is not down more than ______ of its length, it should be left alone unless the metal is too badly burned.

    • A.

      10%

    • B.

      2%

    • C.

      1%

    • D.

      5%

    Correct Answer
    B. 2%
    Explanation
    If a bulge in a boiler is not down more than 2% of its length, it should be left alone unless the metal is too badly burned. This means that if the bulge is less than 2% of the length of the boiler, it is considered acceptable and does not require any immediate action. However, if the metal is severely damaged or burned, it may need to be addressed regardless of the size of the bulge.

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  • 11. 

    1. A dry pipe on a Scotch Marine Boiler is used to remove _____________ from the steam prior to leaving the boiler.

    • A.

      Moisture

    • B.

      Oxygen

    • C.

      Air

    • D.

      CO2

    Correct Answer
    A. Moisture
    Explanation
    A dry pipe on a Scotch Marine Boiler is used to remove moisture from the steam prior to leaving the boiler. This is important because excessive moisture in the steam can cause damage to the piping system and reduce the efficiency of the boiler. By removing moisture, the dry pipe helps to ensure that the steam is dry and of high quality, which is necessary for various industrial processes.

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  • 12. 

    1. The ____________ _________ mechanism on the high limit control call attention if the ________________ control has malfunctioned.

    • A.

      Automatic reset; operating

    • B.

      Automatic reset; burner

    • C.

      Manual reset; operating

    • D.

      Manual reset; burner

    Correct Answer
    C. Manual reset; operating
    Explanation
    The high limit control has two types of reset mechanisms: automatic reset and manual reset. In this case, the correct answer is "manual reset; operating." This means that if the operating control has malfunctioned, the manual reset mechanism on the high limit control will call attention to the issue.

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  • 13. 

    1. An ___________________ Ring is on method used to support the Morrison Tube in a Scotch Marine Boiler.

    • A.

      Adamson

    • B.

      Morrison

    • C.

      Smithers

    • D.

      Faulkner

    Correct Answer
    A. Adamson
    Explanation
    An Adamson Ring is a method used to support the Morrison Tube in a Scotch Marine Boiler. This means that the correct answer is "Adamson" as it is the specific type of ring used for this purpose.

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  • 14. 

    1. A 10 x 5x 15 duplex reciprocating pump has a steam cylinder diameter of ____inches, has a water cylinder diameter of _____ inches, and a long stroke of _____inches.

    • A.

      10, 5, 15

    • B.

      15, 5, 10

    • C.

      5,10, 15

    • D.

      20, 10, 30

    Correct Answer
    A. 10, 5, 15
    Explanation
    The given answer states that the steam cylinder diameter is 10 inches, the water cylinder diameter is 5 inches, and the long stroke is 15 inches. This suggests that the dimensions of the reciprocating pump are such that the steam cylinder has a larger diameter compared to the water cylinder, and the stroke length is longer than the cylinder diameters.

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  • 15. 

    1. Boiler stop valves over 2” diameter must be ______________-___________- and -_________.

    • A.

      Packing Gland and Wheel

    • B.

      Outside Screw and Yolk

    • C.

      Outside Stem and Wheel

    • D.

      Outside Stem and Yolk

    Correct Answer
    B. Outside Screw and Yolk
    Explanation
    Boiler stop valves over 2" diameter must have an outside screw and yolk. This configuration allows for easy operation and control of the valve. The outside screw refers to the screw mechanism that moves the valve stem in and out, while the yolk is the handle or wheel that is used to turn the screw. This design ensures that the valve can be easily opened and closed, providing efficient and reliable control over the flow of steam or water in the boiler system.

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  • 16. 

    1. A centrifugal pump uses a ________ to convert velocity energy to pressure energy.

    • A.

      Impeller

    • B.

      Volute

    • C.

      Guide vanes

    • D.

      Propeller

    Correct Answer
    B. Volute
    Explanation
    A centrifugal pump uses a volute to convert velocity energy to pressure energy. The volute is a curved casing that surrounds the impeller, which is the rotating component of the pump. As the impeller spins, it creates a centrifugal force that pushes the fluid towards the outer edges of the volute. This causes the fluid to gain pressure energy as its velocity decreases. The volute then directs the high-pressure fluid towards the pump outlet, allowing it to be used for various applications such as water circulation, irrigation, or industrial processes.

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  • 17. 

    1. A 26” x 48” x rectangular Duct is replaced with a round Duct. What is the minimum diameter of the round Duct to provide the same area?

    • A.

      39.87'

    • B.

      19.93"

    • C.

      35.33"

    • D.

      17.66"

    Correct Answer
    A. 39.87'
    Explanation
    To find the minimum diameter of the round duct that provides the same area as the rectangular duct, we need to calculate the area of the rectangular duct first. The area of a rectangle is given by the formula length x width. In this case, the length is 48 inches and the width is 26 inches. Therefore, the area of the rectangular duct is 48 x 26 = 1248 square inches.

    Since we want to find the minimum diameter of the round duct with the same area, we can use the formula for the area of a circle, which is π x radius^2. Rearranging the formula, we can solve for the radius: radius = √(area/π). Plugging in the area of the rectangular duct, we get radius = √(1248/π) ≈ 19.93 inches.

    Finally, to find the minimum diameter, we double the radius: diameter = 2 x radius ≈ 39.87 inches.

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  • 18. 

    1. A ________ _______ AHU supplies conditioned air to only one area of the building.

    • A.

      Variable Volume

    • B.

      Constant Volume

    • C.

      Single Zone

    • D.

      Multi Zone

    Correct Answer
    C. Single Zone
    Explanation
    A Single Zone AHU supplies conditioned air to only one area of the building. This means that the AHU is designed to serve a specific zone or room, and the air flow and temperature can be adjusted for that particular area. This type of AHU is commonly used in small spaces or individual rooms where the conditioning needs may differ from other areas of the building.

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  • 19. 

    1. The pipes connecting the water column to the boiler must be a minimum diameter of ____ inch.

    • A.

      2"

    • B.

      2.5"

    • C.

      1"

    • D.

      3/4"

    Correct Answer
    C. 1"
    Explanation
    The pipes connecting the water column to the boiler must have a minimum diameter of 1 inch. This is necessary to ensure proper flow and pressure of water between the water column and the boiler. A smaller diameter pipe may not be able to handle the required volume of water, leading to inadequate water supply and potentially causing issues with the boiler's operation.

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  • 20. 

    1. The two types of electric boilers are _______________ and ______________.

    • A.

      Resistance & electrode

    • B.

      Resistance & capacitance

    • C.

      Arc Tube & electrode

    • D.

      Electrode & capacitance

    Correct Answer
    A. Resistance & electrode
    Explanation
    The correct answer is resistance & electrode. Electric boilers can be categorized into two types based on their heating elements: resistance and electrode. Resistance boilers use electrical resistance to generate heat, while electrode boilers use electric current passing through water to produce heat.

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  • 21. 

    1. There is no _____________ _________ ____ _________________ above the critical pressure, because water and steam have the same density.

    • A.

      Specific Heat of Atomization

    • B.

      Latent Heat of vaporization

    • C.

      Specific heat of vaporization

    • D.

      Latent heat of atomization

    Correct Answer
    B. Latent Heat of vaporization
    Explanation
    The statement in the question suggests that there is no change in density between water and steam above the critical pressure. This indicates that there is no phase change occurring, as the density of water and steam would be different if vaporization was taking place. The term "Latent Heat of vaporization" refers to the amount of heat energy required to convert a liquid into a vapor, and since there is no vaporization happening in this scenario, the latent heat of vaporization would not be applicable.

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  • 22. 

    1. ______ ________________ are used extensively in pulverized-fuel-burning plants in order to keep heat-absorbing surfaces free from soot and ash buildup.

    • A.

      Soot Blowers

    • B.

      Stack Scrubbers

    • C.

      Chain Grate Stokers

    • D.

      Tube puncher

    Correct Answer
    A. Soot Blowers
    Explanation
    Soot blowers are used extensively in pulverized-fuel-burning plants to keep heat-absorbing surfaces free from soot and ash buildup. Soot and ash can accumulate on these surfaces, reducing their efficiency and potentially causing damage. Soot blowers use high-pressure steam or compressed air to remove the buildup, ensuring that the surfaces remain clean and heat transfer is optimized. This helps to maintain the overall efficiency and performance of the plant.

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  • 23. 

    1. ______________ is used on high pressure steam plants to absorb oxygen. It’s is not typically used on low pressure steam plants because it is a slow reaction to absorb oxygen.

    • A.

      Deaerator

    • B.

      Hydrazine

    • C.

      Amines

    • D.

      Oxygen scavengers

    Correct Answer
    B. Hydrazine
    Explanation
    Hydrazine is used on high pressure steam plants to absorb oxygen. It is not typically used on low pressure steam plants because it is a slow reaction to absorb oxygen.

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  • 24. 

    1. According to ASME code a HTHW boiler is any boiler that operates above ____________ or ____________.

    • A.

      150PSI, 200 Deg. F

    • B.

      150 PSI, 100 Deg. C

    • C.

      160PSI, 250Deg.F

    • D.

      14.7 PSI, 212 Deg. F

    Correct Answer
    C. 160PSI, 250Deg.F
    Explanation
    According to the ASME code, a HTHW (High Temperature Hot Water) boiler is defined as a boiler that operates above 160 PSI and 250 degrees Fahrenheit.

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  • 25. 

    1. The waste products from a sugar cane are used in a _______________ plant.

    • A.

      Bagasse

    • B.

      Black liquor

    • C.

      Red liquor

    • D.

      Saccarine refinery

    Correct Answer
    A. Bagasse
    Explanation
    Bagasse is the fibrous residue left after extracting juice from sugar cane. It is a byproduct of the sugar cane industry and is commonly used as a fuel in power plants. Therefore, the waste products from sugar cane, which include bagasse, are used in a power plant.

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  • 26. 

    1. ______________ usually caused cavities to form at grain boundaries in metal, and these cavities coalesce to form cracks.

    • A.

      Corrosion

    • B.

      Crusting

    • C.

      Creep

    • D.

      Grain fatigue

    Correct Answer
    C. Creep
    Explanation
    Creep is the correct answer because it refers to the slow and gradual deformation of a material under constant stress or high temperatures. This can cause cavities to form at the grain boundaries in metal, which then coalesce to form cracks.

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  • 27. 

    1. Cogeneration plants sell ____________ to the local industrial plants, and _____________ to the local __________.

    • A.

      Fuel oil, steam, power plants

    • B.

      Steam, condensate, cogeners

    • C.

      Propane, fuel oil, utilities

    • D.

      Steam, electricity, utilities

    Correct Answer
    D. Steam, electricity, utilities
    Explanation
    Cogeneration plants sell steam and electricity to the local utilities.

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  • 28. 

    1. If a tubesheet is corroded more than ______ percent of the original thickness, the defective section must be cutout and flush patched installed.

    • A.

      10

    • B.

      20

    • C.

      35

    • D.

      50

    Correct Answer
    D. 50
    Explanation
    If a tubesheet is corroded more than 50 percent of the original thickness, the defective section must be cutout and flush patched installed. This means that if the corrosion has caused more than half of the tubesheet's original thickness to be eroded, it is necessary to remove that section and replace it with a flush patch. This is likely because the corrosion has weakened the tubesheet significantly and it cannot function effectively in its current state.

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  • 29. 

    1. A _________ _______AHU has heating and cooling coils located at the different zones. It uses air dampers from the hot and cold ducts to maintain zone comfort.

    • A.

      Variable Volume

    • B.

      Constant Volume

    • C.

      Single Zone

    • D.

      Multi Zone

    Correct Answer
    D. Multi Zone
    Explanation
    A Multi Zone AHU has heating and cooling coils located at different zones, allowing for individual temperature control in each zone. It uses air dampers from the hot and cold ducts to maintain comfort in each zone. This type of AHU is ideal for buildings with multiple areas that require different temperature settings.

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  • 30. 

    1. The operation of a black liquor boiler is known for its __________ generation, and heat recovery of _______ _______.

    • A.

      Steam, sulpfuric acid

    • B.

      Power, waste heat

    • C.

      Lignin, soda ash

    • D.

      Steam, soda ash

    Correct Answer
    D. Steam, soda ash
    Explanation
    The operation of a black liquor boiler is known for its steam generation, which refers to the production of steam as a result of the boiler's operation. Additionally, the boiler is also known for its heat recovery of soda ash, which means that it is able to recover and utilize the waste heat produced during the process to generate soda ash.

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  • 31. 

    1. Number 4 fuel oil has _____________btu’s per pound.

    • A.

      19,720

    • B.

      19,657

    • C.

      22,475

    • D.

      18,840

    Correct Answer
    D. 18,840
    Explanation
    Number 4 fuel oil has 18,840 btu's per pound.

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  • 32. 

    1. Leaking safety valve should be ____________ to stop the leakage, never ___________.by adjustment to stop the leakage.

    • A.

      Recalibrated, patched

    • B.

      Replaced, patched

    • C.

      Reground, tightened

    • D.

      Replaced, tightened

    Correct Answer
    C. Reground, tightened
    Explanation
    When a safety valve is leaking, it means that it is not sealing properly. To fix this issue, the valve should be reground, which involves smoothing the surface of the valve and its seat to ensure a proper seal. Additionally, the valve should be tightened to ensure that it is securely closed and no leakage occurs. Patching or replacing the valve would not address the underlying issue of improper sealing.

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  • 33. 

    1. Hardness is a measure of the ____________ and _______________ ions in solution.

    • A.

      Calcium, bicarbonate

    • B.

      Calcium, sulphate

    • C.

      Calcium, magnesium

    • D.

      Carbonate, bicarbonate

    Correct Answer
    C. Calcium, magnesium
    Explanation
    Hardness is a measure of the concentration of calcium and magnesium ions in solution. These ions contribute to the overall hardness of water. Calcium and magnesium ions can come from various sources, such as dissolved minerals in the ground or rocks. The presence of these ions can affect the taste, appearance, and performance of water in various applications, such as in industrial processes or household use. Therefore, measuring the concentration of calcium and magnesium ions is important in determining the hardness of water.

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  • 34. 

    1. Operating a boiler at temperatures 10° to 20°F above the design temperature for long period of time can cause a life reduction of _____ to _____ years.

    • A.

      10-20

    • B.

      5-10

    • C.

      20-40

    • D.

      15-30

    Correct Answer
    A. 10-20
    Explanation
    Operating a boiler at temperatures 10°F to 20°F above the design temperature for a long period of time can cause a reduction in its lifespan by 10 to 20 years.

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  • 35. 

    1. A dual Duct AHU has hot and cold Ducts connected to ___________ _______.

    • A.

      Supply Duct

    • B.

      Return Duct

    • C.

      VAV BOX

    • D.

      Mixing Box

    Correct Answer
    D. Mixing Box
    Explanation
    A dual Duct AHU has hot and cold Ducts connected to a Mixing Box. The Mixing Box is responsible for mixing the hot and cold air streams to achieve the desired temperature before supplying it to the conditioned space. This allows for precise control over the temperature of the supplied air.

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  • 36. 

    1. A terminal reheat AHU delivers air at constant ______ degrees. A reheat coil is connected to the thermostat to maintain comfort in the space.

    • A.

      55

    • B.

      65

    • C.

      58

    • D.

      62

    Correct Answer
    A. 55
    Explanation
    A terminal reheat AHU delivers air at a constant temperature of 55 degrees. This is achieved by using a reheat coil connected to the thermostat, which allows for the adjustment of the air temperature to maintain comfort in the space.

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  • 37. 

    1. An induction AHU used High Pressure air flowing through the ________ to draw air across the heating coil.

    • A.

      Induction coils

    • B.

      Induction nozzles

    • C.

      Venturi nozzles

    • D.

      Induction vanes

    Correct Answer
    B. Induction nozzles
    Explanation
    An induction AHU (Air Handling Unit) uses high pressure air flowing through the induction nozzles to create a low pressure zone, which in turn draws air across the heating coil. The induction nozzles create a venturi effect, where the high velocity air passing through the nozzles creates a low pressure zone that draws in surrounding air. This allows the AHU to efficiently heat or cool the air passing through the heating coil.

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  • 38. 

    1. When two or more boilers are connected into a common steam header, and each boiler is equipped with a man-hole,_____ stop valves must be used on each boiler.

    • A.

      4

    • B.

      3

    • C.

      5

    • D.

      2

    Correct Answer
    D. 2
    Explanation
    When two or more boilers are connected into a common steam header, and each boiler is equipped with a man-hole, 2 stop valves must be used on each boiler. This is because having 2 stop valves on each boiler provides an additional level of safety and allows for maintenance and repairs to be carried out on one valve while the other valve remains operational. It also helps in isolating the boiler from the common header in case of any emergency or maintenance requirements.

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  • 39. 

    1. Galvanic corrosion occurs when ______________, metals are in direct contact with each other in a _______________ environment.

    • A.

      Similar, humid

    • B.

      Similar, conductive

    • C.

      Disimilar, humid

    • D.

      Disimilar, conductive

    Correct Answer
    D. Disimilar, conductive
    Explanation
    Galvanic corrosion occurs when dissimilar metals are in direct contact with each other in a conductive environment. This is because when two different metals come into contact, an electrochemical reaction takes place due to the difference in their electrical potentials. The conductive environment facilitates the flow of electrons between the metals, leading to the corrosion of the less noble metal. The presence of moisture or humidity further accelerates this corrosion process.

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  • 40. 

    1. A stay that is shorter than 8” and threaded is required to have a blank

    • A.

      Tell tale hole

    • B.

      Stay brace

    • C.

      Riveted connection

    • D.

      Bolt brace

    Correct Answer
    A. Tell tale hole
    Explanation
    A stay that is shorter than 8" and threaded is required to have a tell tale hole.

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  • 41. 

    1. A ___________ Pump is a Positive Displacement Pump.

    • A.

      Centrifugal

    • B.

      Duplex

    • C.

      Rotary

    • D.

      Reciprocating

    Correct Answer
    C. Rotary
    Explanation
    A rotary pump is a positive displacement pump because it uses rotating mechanisms, such as gears or lobes, to create suction and move fluid through the pump. This type of pump works by trapping fluid between rotating components and the pump housing, then forcing the fluid through the pump chamber. Unlike centrifugal pumps, which rely on centrifugal force to move fluid, rotary pumps provide a consistent flow rate and can handle high viscosity fluids. Therefore, a rotary pump is a type of positive displacement pump.

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  • 42. 

    1. In lieu of a stop valve a ____________ _____may be used instead of the stop valve ___________ to the boiler.

    • A.

      Non-return valve, closest

    • B.

      Non-return valve, farthest

    • C.

      Check valve, closest

    • D.

      Check valve, fartherst

    Correct Answer
    A. Non-return valve, closest
    Explanation
    A non-return valve may be used instead of a stop valve that is closest to the boiler. A non-return valve allows fluid or gas to flow in only one direction, preventing backflow. In this case, it would prevent any fluid or gas from flowing back into the boiler when the stop valve is closed. Using a non-return valve closest to the boiler ensures that it is positioned in the most effective location to prevent backflow.

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  • 43. 

    1. A slow opening blowdown valve must complete _____ turns between full open and full shut.

    • A.

      3

    • B.

      2

    • C.

      5

    • D.

      4

    Correct Answer
    C. 5
  • 44. 

    What is the restriction in circulation due to a steam pocket inside the pump.

    • A.

      Pump cavitation

    • B.

      Steam bound

    • C.

      Vacuum bound

    • D.

      Vacuum cavitation

    Correct Answer
    B. Steam bound
    Explanation
    The restriction in circulation due to a steam pocket inside the pump is known as "steam bound." Steam binding occurs when steam pockets form within the pump, leading to a decrease in the pump's efficiency and potential damage. The steam pockets hinder the normal flow of liquid, causing disruptions in circulation. This phenomenon is associated with issues such as cavitation, where the formation and collapse of vapor bubbles result in mechanical stress and damage to pump components. Proper pump design, operation, and maintenance practices are crucial to prevent steam binding and related problems. 

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  • 45. 

    1. One grain is equal to ________ parts per million.

    • A.

      17.1

    • B.

      18.5

    • C.

      10

    • D.

      33.3

    Correct Answer
    A. 17.1
    Explanation
    Parts per million (ppm) is a unit used to express the concentration of a substance in a solution. It represents the number of parts of the substance per one million parts of the solution. In this case, one grain is equal to 17.1 parts per million.

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  • 46. 

    1. Name the 4 steps needed to perform regeneration on a zeolite water softer _____________, ________________, ________________________, _____________________________.

    • A.

      Pre-rinse, backwash, membrane sweep, regenration

    • B.

      Brine rinse, backwash, membrane sweep, back in service

    • C.

      Backwash, Brine Rinse, slow / fast rinse, back in service

    • D.

      Backwash, brine rinse, slow / fast rinse, regeneration

    Correct Answer
    C. Backwash, Brine Rinse, slow / fast rinse, back in service
    Explanation
    The correct answer is "Backwash, Brine Rinse, slow / fast rinse, back in service." These are the four steps needed to perform regeneration on a zeolite water softener. First, the system needs to be backwashed to remove any accumulated debris or contaminants. Then, a brine rinse is done to flush out the accumulated hardness minerals from the zeolite resin bed. After that, a slow or fast rinse is performed to ensure that all the brine solution is removed from the system. Finally, the system is put back in service, ready to soften water again.

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  • 47. 

    1. A solid that precipitates out of solution and adhere to the boiler heating surfaces is called__________.

    • A.

      Scale

    • B.

      Precipitant

    • C.

      Crust

    • D.

      Embrittlement

    Correct Answer
    A. Scale
    Explanation
    Scale is the correct answer because it refers to the solid that forms and adheres to the heating surfaces of a boiler. This scale is typically formed when minerals and impurities in the water precipitate out and accumulate over time, reducing the efficiency of the boiler and potentially causing damage.

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  • 48. 

    1. In a ___________ water softener, calcium and magnesium ions are exchanged for sodium ions. The result is a soft salt sludge that can be easily removed by bottom blowdown.

    • A.

      Zeolite

    • B.

      Sodium bicabonate

    • C.

      Activated carbon

    • D.

      Ion exchange

    Correct Answer
    A. Zeolite
    Explanation
    In a zeolite water softener, calcium and magnesium ions are exchanged for sodium ions. Zeolite is a type of mineral with a porous structure that allows it to trap and exchange ions. When hard water passes through the zeolite resin bed, the calcium and magnesium ions are attracted to the zeolite and are replaced by sodium ions. This process effectively softens the water by reducing the concentration of calcium and magnesium ions. The softened water then flows out of the system, while the calcium and magnesium ions are retained in the zeolite resin bed, forming a soft salt sludge that can be easily removed by bottom blowdown.

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  • 49. 

    1. The color of Cylinder containing R-11 is _________.

    • A.

      Orange

    • B.

      White

    • C.

      Light Green

    • D.

      Coral Red

    Correct Answer
    A. Orange
    Explanation
    The color of the cylinder containing R-11 is orange.

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  • 50. 

    1. A ____________________ pump can be started with the discharge valve shut.

    • A.

      Centrifugal

    • B.

      Rotary

    • C.

      Reciprocating

    • D.

      Simplex

    Correct Answer
    A. Centrifugal
    Explanation
    A centrifugal pump can be started with the discharge valve shut because it uses centrifugal force to move the fluid. When the pump is started, the impeller spins rapidly, creating a centrifugal force that pushes the fluid towards the outer edges of the impeller. This force allows the fluid to be pushed through the pump even with the discharge valve shut.

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Mike Jewel |Stationary Engineer
Mike, a state and municipally licensed steam and stationary engineer, boasts over 20 years of experience in building trades. His expertise reflects a seasoned professional dedicated to his craft.

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