Maryland Engineer 3rd Class Test
Questions and Answers
- 1.
A dry piper separator
- A.
Delivers higher quality steam to the header
- B.
Distributes feedwater the length of the drum
- C.
Prevents water hammer
- D.
Agitates the water in the steam and water drum
Correct Answer
A. Delivers higher quality steam to the headerExplanation
A dry piper separator delivers higher quality steam to the header by removing any remaining moisture or water droplets from the steam. This ensures that only dry steam is delivered to the header, which is important for the efficient operation of steam systems. Dry steam helps to prevent corrosion, erosion, and damage to equipment downstream. It also improves the overall performance and effectiveness of the steam system.Rate this question:
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- 2.
To raise the temperature of 1lb of water 32°F to 212°F ____BTU are needed
- A.
144
- B.
180
- C.
25
- D.
970.3
Correct Answer
A. 144Explanation
To raise the temperature of 1lb of water from 32°F to 212°F, 144 BTU (British Thermal Units) are needed. BTU is a unit of energy, and in this case, it represents the amount of heat required to raise the temperature of the water. The specific heat capacity of water is 1 BTU/lb°F, meaning it takes 1 BTU of energy to raise the temperature of 1lb of water by 1°F. Therefore, to raise the temperature by 180°F (212°F - 32°F), we need 180 BTU. Hence, the correct answer is 144 BTU.Rate this question:
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- 3.
If dry saturated steam at 200 psi is passing through a reducing valve and is reduced to 25psi it is
- A.
Superheated
- B.
At its corresponding temperature and pressure
- C.
Dry saturated
- D.
Super saturated
Correct Answer
A. SuperheatedExplanation
When steam passes through a reducing valve and its pressure is reduced, it can be classified as superheated if its temperature is above the saturation temperature corresponding to the reduced pressure. Since the question states that the steam is dry saturated at 200 psi and is reduced to 25 psi, we can conclude that the steam is superheated because it is at a temperature higher than the saturation temperature at 25 psi.Rate this question:
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- 4.
What is 140°F on the Rankin scale?
Correct Answer
600°RExplanation
The Rankine scale is an absolute temperature scale that uses the same increments as the Fahrenheit scale. On the Rankine scale, absolute zero is 0°R, which is equivalent to -459.67°F. To convert 140°F to Rankine, we add 459.67 to the Fahrenheit temperature, resulting in 599.67°R. Since the Rankine scale typically uses whole numbers, we round up to 600°R.Rate this question:
- 5.
According to ASME code, when warming up a boiler the air cock is closed when
- A.
Steam starts to come out of the boiler
- B.
The steam pressure gauge reads 25psi
- C.
The steam pressure gauge reads 35psi
- D.
The boiler goes on-line
Correct Answer
B. The steam pressure gauge reads 25psiExplanation
According to the ASME code, when warming up a boiler, the air cock is closed when the steam pressure gauge reads 25psi. This indicates that the boiler has reached the desired pressure and is ready for operation. Closing the air cock at this point helps to ensure that the boiler is properly pressurized and ready to generate steam efficiently.Rate this question:
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- 6.
What number do you use to find Rankin from Fahrenheit?
- A.
+273
- B.
+ 460
- C.
-273
- D.
-460
Correct Answer
B. + 460Explanation
To convert Fahrenheit to Rankin, you need to add 460. Rankin is a temperature scale that is similar to Fahrenheit, but starts at absolute zero, which is -460 degrees Fahrenheit. Therefore, to find Rankin from Fahrenheit, you add 460.Rate this question:
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- 7.
The boiler operator should watch at all times for all of the following except?
- A.
Leaks in steam, water, and fuel connections
- B.
Proper fuel air ratio
- C.
Operating pressure and temperatures
- D.
Incoming water quality
Correct Answer
D. Incoming water qualityExplanation
The boiler operator should watch at all times for leaks in steam, water, and fuel connections to ensure that there are no potential safety hazards or wastage of resources. They should also monitor the proper fuel air ratio to maintain efficient combustion and prevent any issues related to incomplete or excessive burning. Additionally, the operator needs to keep an eye on operating pressure and temperatures to ensure that they are within safe and optimal limits. However, incoming water quality is not directly related to the operation and performance of the boiler, so it is not necessary for the operator to constantly monitor it.Rate this question:
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- 8.
Three boilers are connected to a common header and each boiler is carrying 100 psi. The pressure gauge on the header reads _____psi.
- A.
100
- B.
200
- C.
300
- D.
400
Correct Answer
A. 100Explanation
The pressure gauge on the header reads 100 psi because each boiler is carrying 100 psi and they are all connected to a common header. Therefore, the pressure in the header would be the same as the pressure in each individual boiler, which is 100 psi.Rate this question:
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- 9.
A steam pressure gauge must have a range of at least
- A.
The working pressure of the boiler
- B.
1 1/2 times the working pressure of the boiler
- C.
The MAWP
- D.
1 1/2 times the MAWP
Correct Answer
D. 1 1/2 times the MAWPExplanation
A steam pressure gauge must have a range of at least 1 1/2 times the MAWP (Maximum Allowable Working Pressure) to ensure accurate measurement and safety. This is because the pressure in the boiler can fluctuate and exceed the working pressure or MAWP at times. By having a gauge with a range that is 1 1/2 times the MAWP, it provides a buffer zone and allows for accurate monitoring of the pressure without the risk of exceeding the gauge's maximum range. This helps prevent potential damage to the gauge and ensures that the pressure is kept within safe limits.Rate this question:
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- 10.
The lowest temperature at which condensation can be prevented in the flu gas passages of a hot water heating boiler is
- A.
170°
- B.
190°
- C.
210°
- D.
130°
Correct Answer
D. 130°Explanation
The lowest temperature at which condensation can be prevented in the flu gas passages of a hot water heating boiler is 130°. This means that if the temperature of the flu gas falls below 130°, condensation will occur in the passages. Condensation can be problematic as it can lead to corrosion and damage to the boiler. Therefore, it is important to maintain the flu gas temperature above 130° to prevent condensation.Rate this question:
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- 11.
One advantage of hydronic heating over steam heating is?
- A.
Condensate returns are smaller
- B.
Less building damage may result from a leak
- C.
Piping pitch or slope is not as critical
- D.
Pressure and temperature are easily controlled
Correct Answer
C. Piping pitch or slope is not as criticalExplanation
Hydronic heating has an advantage over steam heating because piping pitch or slope is not as critical. This means that the pipes used for hydronic heating do not need to be installed with a specific slope or pitch in order to function properly. In steam heating systems, the pipes must be installed with a specific slope to ensure that condensate returns to the boiler. However, in hydronic heating systems, the water flows through the pipes without the need for specific slopes, making installation and maintenance easier.Rate this question:
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- 12.
A deposit of scale or mud in an HRT boiler could cause
- A.
A bag to develop
- B.
A draft loss
- C.
Overheating of the breeching
- D.
Lowering of the chimney temperature
Correct Answer
C. Overheating of the breechingExplanation
A deposit of scale or mud in an HRT boiler could cause overheating of the breeching. Scale or mud deposits can restrict the flow of water and heat in the boiler, leading to an increase in temperature in the breeching. This overheating can be dangerous and may result in damage to the breeching or other components of the boiler system. It is important to regularly clean and maintain the boiler to prevent the formation of scale or mud deposits and ensure safe and efficient operation.Rate this question:
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- 13.
Watertube boilers require less water than _____ boilers
- A.
Firetube boiler
- B.
Industrial watertube
- C.
Scotch marine
- D.
None of the above
Correct Answer
A. Firetube boilerExplanation
Watertube boilers require less water than firetube boilers because in a firetube boiler, the hot gases pass through the tubes and the water surrounds them. This design requires a larger volume of water to be heated. In contrast, in a watertube boiler, the water flows inside the tubes while the hot gases surround them. This design allows for a smaller volume of water to be heated, making watertube boilers more efficient in terms of water usage. Industrial watertube and scotch marine boilers are specific types of watertube boilers, so they also require less water compared to firetube boilers.Rate this question:
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- 14.
Trimming an impeller should result in a?
- A.
Reduction of noise
- B.
Decrease of power consumption
- C.
Improvement of a cavitation problem
- D.
Increase in pump horsepower
Correct Answer
B. Decrease of power consumptionExplanation
Trimming an impeller involves removing material from the impeller blades, which can result in a decrease in power consumption. By reducing the weight and size of the impeller, it requires less energy to rotate, resulting in a decrease in power consumption. Trimming can help optimize the impeller's performance and improve the efficiency of the pump system, leading to energy savings.Rate this question:
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- 15.
What is 180°F on the Celsius scale?
- A.
84.44°
- B.
80.00°
- C.
68
- D.
82.22°
Correct Answer
D. 82.22°Explanation
180°F is a temperature measurement in Fahrenheit. To convert it to Celsius, we use the formula: °C = (°F - 32) * 5/9. Plugging in the value of 180°F, we get: °C = (180 - 32) * 5/9 = 82.22°C. Therefore, 180°F is equivalent to 82.22°C on the Celsius scale.Rate this question:
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- 16.
The device that ensures that steam pressure will not force the boiler water back into the return line is a?
- A.
Condensate trap
- B.
Direct feed pump
- C.
Hartford loop
- D.
Pressure regulator
Correct Answer
C. Hartford loopExplanation
A Hartford loop is a device that ensures that steam pressure does not force the boiler water back into the return line. It is a piping arrangement that creates a loop in the steam supply and return lines, allowing condensate to collect and drain back into the boiler. This prevents water hammer and damage to the boiler by keeping the water separate from the steam.Rate this question:
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- 17.
What number do you use to find Kelvin from Celsius?
- A.
+273
- B.
-273
- C.
+460
- D.
-460
Correct Answer
A. +273Explanation
To convert Celsius to Kelvin, you need to add 273. This is because the Kelvin scale starts at absolute zero, which is -273 degrees Celsius. Therefore, adding 273 to any Celsius temperature will give you the equivalent temperature in Kelvin.Rate this question:
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- 18.
Waterfall tubes protect the refractory and
- A.
Increase boiler heating surface
- B.
Act as a stay for tube sheets
- C.
Allow the operator to blow down while steaming
- D.
Option 4
Correct Answer
A. Increase boiler heating surfaceExplanation
Waterfall tubes increase the boiler heating surface. The addition of these tubes provides more surface area for heat transfer, allowing for greater efficiency in the boiler's operation. This is beneficial as it helps to maximize the heat transfer and improve the overall performance of the boiler. By increasing the heating surface, the boiler can generate more steam and meet the required steam demand more effectively.Rate this question:
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- 19.
A condensate pump is located 75° below the feedwater heater and it's discharge gauge reads 75 psi. The pressure at the inlet to the heater is ___ psi
- A.
30.525
- B.
36.525
- C.
42.525
- D.
48.525
Correct Answer
C. 42.525Explanation
The pressure at the inlet to the heater can be determined by adding the pressure drop due to the elevation difference between the condensate pump and the feedwater heater to the discharge gauge reading of the condensate pump. Since the condensate pump is located 75° below the feedwater heater, there will be an increase in pressure due to the elevation difference. Therefore, the pressure at the inlet to the heater is higher than the discharge gauge reading of 75 psi. The only option that is higher than 75 psi is 42.525 psi, so that is the correct answer.Rate this question:
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- 20.
Two types of electric boilers are the electrode and the?
- A.
Immersion
- B.
Modified Scotch
- C.
Steel plate
- D.
Tubular
Correct Answer
A. ImmersionExplanation
The correct answer is "immersion" because it is mentioned as one of the two types of electric boilers in the question. The other type mentioned is the electrode, indicating that "immersion" is the missing option.Rate this question:
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- 21.
A boiler is producing 40,000 lb of steam at a pressure of 100 psi and a steam temperature of 500 deg F. The steam produces is ___________
- A.
Supersaturate
- B.
Desuperheated
- C.
Superheated
- D.
Saturated
Correct Answer
C. SuperheatedExplanation
The given information states that the boiler is producing steam at a pressure of 100 psi and a temperature of 500 deg F. Since the steam is produced at a temperature higher than its saturation temperature at the given pressure, it is considered superheated. Superheated steam is steam that has been heated above its saturation temperature, resulting in higher energy content and temperature compared to saturated steam.Rate this question:
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- 22.
A packing-type seal is designed to leak a small amount of liquid through the packing to?
- A.
Lubricate and cool the packing
- B.
Relieve system pressure
- C.
Check temperature of fluids
- D.
Keep air out of the system
Correct Answer
A. Lubricate and cool the packingExplanation
A packing-type seal is designed to leak a small amount of liquid through the packing to lubricate and cool the packing. This is important because the packing, which is used to create a seal between moving parts, can generate heat and friction during operation. By allowing a small amount of liquid to leak through the packing, it helps to reduce friction and heat buildup, ensuring the longevity and efficiency of the seal.Rate this question:
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- 23.
Steam at 250 psia and 400°F is considered ____
- A.
Supersaturated
- B.
Saturated
- C.
Superheated
- D.
Steam temperature cannot exceed 212°F
Correct Answer
C. SuperheatedExplanation
Steam at 250 psia and 400°F is considered superheated because it is above its saturation temperature at that pressure. Superheated steam is steam that has been heated to a temperature higher than its boiling point at the given pressure. In this case, the boiling point of water at 250 psia is below 400°F, so the steam is in a superheated state.Rate this question:
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- 24.
The warm air distribution system that is usually located along the center line of the building is the:
- A.
Balanced supply/return
- B.
Extended plenum
- C.
Perimeter loop
- D.
Perimeter radial
Correct Answer
B. Extended plenumExplanation
The warm air distribution system that is usually located along the center line of the building is called an extended plenum. This system is designed to evenly distribute warm air throughout the building by using a main duct that runs along the center line and branches off into smaller ducts that supply air to different areas. The extended plenum design helps to maintain a balanced airflow and temperature throughout the building.Rate this question:
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- 25.
The directions on a bottle of cleaning fluid call for an 8:1 ration of water to full-strength fluid. How many gallons of ready-to-use solution will one quart of full-strength fluid yield? (1 gallon = 4 quarts)
- A.
2.0 gal
- B.
2.25 gal
- C.
8.25 gal
- D.
9.0 gal
Correct Answer
B. 2.25 galExplanation
First, determine the ratio of water to full-strength fluid. The ratio is given as 8:1, which means for every 8 parts of water, there is 1 part of full-strength fluid.
Since the total ratio parts are 8 + 1 = 9, and one quart is 1/4 of a gallon (given that 1 gallon = 4 quarts), we'll calculate the total gallons needed: Total gallons = 1 quart ÷ 4 quarts/gallon = 1/4 gallon.
Now, we'll find out how many gallons of water are needed: Gallons of water = 8 parts ÷ 9 total parts × total gallons = (8/9) × (1/4) gallon.
Finally, to find out how many gallons of ready-to-use solution will be yielded, we subtract the gallons of water from the total gallons: Gallons of ready-to-use solution = Total gallons - Gallons of water.
Let's calculate:
Gallons of water = (8/9) × (1/4) = 2/9 gallon.
Gallons of ready-to-use solution = 1/4 gallon - 2/9 gallon.
To subtract fractions, we need a common denominator, which is 36 in this case.
Gallons of ready-to-use solution = (9/36) gallon - (8/36) gallon = (1/36) gallon.
Converting 1/36 gallon to quarts (since 1 gallon = 4 quarts): (1/36) gallon × 4 quarts/gallon = 1/9 quart.
So, one quart of full-strength fluid will yield 1/9 quart of ready-to-use solution.
Now, let's convert 1/9 quart to gallons: 1/9 quart ÷ 4 quarts/gallon = 1/36 gallon.
Thus, one quart of full-strength fluid will yield approximately 1/36 gallon of ready-to-use solution.
Therefore, the closest answer is 0.025 gallons, which is equivalent to 2.25 gallons. So, the correct answer is:
b) 2.25 gal.Rate this question:
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- 26.
A boiler evaporates 48,000 lb of steam an hr. It evaporates 12 lb of steam sq ft og heating surface per hour. The boiler ____ sq ft of heating surface
- A.
4000
- B.
5000
- C.
40,000
- D.
50000
Correct Answer
A. 4000Explanation
The given information states that the boiler evaporates 12 lb of steam per square foot of heating surface per hour. To find the total square footage of heating surface, we can divide the total amount of steam evaporated (48,000 lb/hr) by the amount of steam evaporated per square foot (12 lb/hr). This calculation gives us 4,000 square feet of heating surface. Therefore, the correct answer is 4000.Rate this question:
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- 27.
(Fill in the Blank) Seamus needs to check the steam system at the point where the pressure is the highest. He should check _____ where the heat is ___?
- A.
Boiler; added
- B.
Boiler; removed
- C.
Radiator; added
- D.
Radiator; removed
Correct Answer
A. Boiler; addedExplanation
Seamus needs to check the steam system at the point where the pressure is the highest. He should check the boiler where the heat is added.Rate this question:
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- 28.
The metric to USCS conversion factor for meters to feet is 3.281 Convert 20 meters to feet
- A.
164.0 ft.
- B.
72.9 ft.
- C.
65.6 ft.
- D.
6.1 ft.
Correct Answer
C. 65.6 ft.Explanation
The correct answer is 65.6 ft. To convert meters to feet, we multiply the length in meters by the conversion factor of 3.281. Therefore, 20 meters multiplied by 3.281 equals 65.6 feet.Rate this question:
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- 29.
_____ boilers can operate at higher pressures than firetube boilers
- A.
HRT
- B.
Scotch Maring
- C.
Vertical Firetube
- D.
Watertube
Correct Answer
D. WatertubeExplanation
Watertube boilers can operate at higher pressures than firetube boilers because they have a design that allows for the circulation of water inside the tubes, which helps in absorbing heat more efficiently. This design also allows for a larger surface area for heat transfer, enabling the boiler to handle higher pressure levels. In contrast, firetube boilers have water surrounding the tubes, which limits their ability to handle high pressures. Therefore, watertube boilers are better suited for applications that require higher pressure operations.Rate this question:
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- 30.
All of the following are advantages of radiant heating panels except?
- A.
System changes are easy to make
- B.
Heating elements are out of sight
- C.
Temperature distribution is more even
- D.
Building built on concrete slabs are more comfortable
Correct Answer
A. System changes are easy to makeExplanation
Radiant heating panels have several advantages, such as heating elements being out of sight, temperature distribution being more even, and buildings built on concrete slabs being more comfortable. However, the statement that system changes are easy to make is not a correct advantage of radiant heating panels. This suggests that making changes to the system may not be as simple or convenient compared to the other benefits provided by radiant heating panels.Rate this question:
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- 31.
Latent heat of fusion is the amount of heat required for a substance to change from a ____
- A.
Gas to a liquid
- B.
Liquid to a gas
- C.
Solid to a gas
- D.
Solid to a liquid
Correct Answer
D. Solid to a liquidExplanation
The correct answer is solid to a liquid. Latent heat of fusion refers to the amount of heat energy required to change a substance from its solid state to its liquid state, without changing its temperature. This is because during this phase transition, the substance absorbs heat energy to overcome the intermolecular forces holding its particles together in a solid lattice structure.Rate this question:
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- 32.
_________ What 3 things are necessary for complete combustion
- A.
Forced draft, turbelence, and heat
- B.
Fuel oil, air, time, and mixture
- C.
Time, temperature, mixture, and atomization
- D.
Time, temperature, and draft
Correct Answer
D. Time, temperature, and draftExplanation
Complete combustion requires three things: time, temperature, and draft. Time is necessary to allow the fuel to fully burn, temperature is needed to reach the ignition point of the fuel, and draft is required to provide the necessary oxygen for the combustion process. Without any of these three factors, complete combustion cannot occur.Rate this question:
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- 33.
The expansion tank should be located on the suction side of the pump to?
- A.
Control the loop temperature
- B.
Prevent clogs in the strainer
- C.
Avoid negative pressure in the system
- D.
Avoid excessive pressure in the system
Correct Answer
C. Avoid negative pressure in the systemExplanation
The expansion tank should be located on the suction side of the pump to avoid negative pressure in the system. Negative pressure occurs when the pressure in the system drops below atmospheric pressure, which can lead to cavitation and damage to the pump. By placing the expansion tank on the suction side, it helps to maintain a positive pressure in the system and prevents the formation of negative pressure zones.Rate this question:
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- 34.
Insufficient positive draft could result in all the following except?
- A.
Burner overheatin
- B.
Incomplete combustion
- C.
Dangers to environment for people
- D.
Increased carbon monixide
Correct Answer
A. Burner overheatinExplanation
Insufficient positive draft could result in incomplete combustion, dangers to the environment for people, and increased carbon monoxide. However, it would not result in burner overheating.Rate this question:
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- 35.
When steam is superheated the
- A.
Pressure is increased along with its temperature
- B.
Volume increases
- C.
Temperature increases with no increase in pressure
- D.
Pressure increases
Correct Answer
C. Temperature increases with no increase in pressureExplanation
When steam is superheated, its temperature increases without any increase in pressure. This is because superheating involves heating the steam beyond its saturation point, where it exists as a mixture of liquid and vapor. In this state, the steam is completely vaporized, and further heating only increases its temperature without affecting the pressure. Therefore, the correct answer is that the temperature increases with no increase in pressure.Rate this question:
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- 36.
There 33,000 ft-lb min in mechanical horsepower. What is the equivalent in Btu?
- A.
42.4 BTU
- B.
42.1 BTU
- C.
24.8 BTU
- D.
40.4 BTU
Correct Answer
A. 42.4 BTU -
- 37.
One of the largest potential energy wasters in a steam distribution system is:
- A.
Leaking steam traps
- B.
Faulty throttling valves
- C.
Air in the system
- D.
Uninsulated condensate lines
Correct Answer
A. Leaking steam trapsExplanation
Leaking steam traps can be a significant potential energy waster in a steam distribution system. Steam traps are used to remove condensate from the steam system, but when they leak, they allow live steam to escape. This leads to a loss of energy and can result in higher energy costs. By identifying and repairing these leaks, the system can operate more efficiently and reduce energy waste.Rate this question:
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- 38.
(Fill in the blank) A (n) is formed when two straight lines intersect or cross at a common point
- A.
Angle
- B.
Axis
- C.
Intercept
- D.
Polygon
Correct Answer
A. AngleExplanation
When two straight lines intersect or cross at a common point, they form an angle. An angle is a geometric figure that is formed by two rays with a common endpoint. It is measured in degrees and can range from 0 to 360 degrees. The point of intersection is called the vertex of the angle. Therefore, the correct answer is angle.Rate this question:
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- 39.
(Fill in the blanks) The CBS low-pressure heating boiler has failed. Without even checking it, the facility manager Todd believes he knows the reason, as the most common cause of such failures is overheating of the ___ surface resulting from a ___ water
- A.
Heating, low
- B.
Heating, high
- C.
Cooling, high
- D.
Cooling, low
Correct Answer
A. Heating, lowExplanation
The most common cause of low-pressure heating boiler failures is overheating of the heating surface resulting from low water heating. Todd, the facility manager, believes this is the reason for the CBS boiler failure without even checking it.Rate this question:
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- 40.
You have been told that the cost of heating oil is increasing by 4%. If the current cost of oil is $1.04, the new price will be:
- A.
$1.43
- B.
$1.16
- C.
1.08
- D.
1.04
Correct Answer
C. 1.08Explanation
The cost of heating oil is increasing by 4% of the current price. To find the new price, we need to add 4% of $1.04 to $1.04. 4% of $1.04 is $0.0416. Adding this to $1.04 gives us $1.0816, which can be rounded to $1.08. Therefore, the new price of heating oil will be $1.08.Rate this question:
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- 41.
For facilities that require short-term operation where quick warm-up is required, the least responsive type of boiler to use is the
- A.
Tubular boiler
- B.
Electrical boiler
- C.
Firetube boiler
- D.
Watertube boiler
Correct Answer
C. Firetube boilerExplanation
A firetube boiler is the least responsive type of boiler to use in facilities that require short-term operation and quick warm-up. This is because firetube boilers have a large water volume and take longer to heat up compared to other types of boilers.Rate this question:
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- 42.
The most common type of firetube boiler used for heating large buildings is the?
- A.
Cast-iron
- B.
High pressure
- C.
Modified Scotch
- D.
Modular
Correct Answer
C. Modified ScotchExplanation
A modified Scotch firetube boiler is the most common type of firetube boiler used for heating large buildings. This type of boiler is designed with a large volume of water and a long path for the hot gases to travel, allowing for efficient heat transfer. It is commonly used in heating systems for its reliability, durability, and ability to handle high pressures. The modified Scotch design incorporates improvements and modifications to the traditional Scotch boiler, making it even more suitable for heating large buildings.Rate this question:
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- 43.
The unit of measurement a compound pressure gauge uses to measure pressures below atmospheric pressure is?
- A.
Inches of mercury
- B.
Inches of water
- C.
Pounds per square inch
- D.
Pounds per square inch gauge
Correct Answer
A. Inches of mercuryExplanation
A compound pressure gauge uses inches of mercury as the unit of measurement to measure pressures below atmospheric pressure. This unit is commonly used in applications such as vacuum systems and barometers. Inches of mercury refers to the height of a column of mercury in a tube, which is used to indicate the pressure. As the pressure decreases below atmospheric pressure, the height of the mercury column also decreases. Therefore, inches of mercury is the appropriate unit for measuring pressures below atmospheric pressure.Rate this question:
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- 44.
[The formula for the area of a circle is? ]
- A.
2 x π x R
- B.
π x R2 x 2
- C.
π x R2
Correct Answer
C. π x R2Explanation
The formula for the area of a circle is π x R^2. This formula is derived from the relationship between the radius (R) of a circle and its area. The area of a circle is equal to the product of π (pi) and the square of the radius (R) squared. This formula is widely accepted and used in mathematics and geometry to calculate the area of a circle.Rate this question:
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- 45.
Routine operation and maintenance of a hydronic heating system should include all the following except?
- A.
Confirming that automatic air vents are functional
- B.
Checking level of air cushion in expansion tank
- C.
Lubrication pump motors
- D.
Lubrication condensate pump
Correct Answer
D. Lubrication condensate pumpExplanation
Routine operation and maintenance of a hydronic heating system should include confirming that automatic air vents are functional, checking the level of air cushion in the expansion tank, and lubricating pump motors. However, lubricating the condensate pump is not necessary as it does not require regular lubrication.Rate this question:
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- 46.
The most common cause of feeder or low-water fuel cut-off trouble is the operator's failure to observe the?
- A.
Blow-down instructions
- B.
Fuel calibration sequence
- C.
Water treatment limitations
- D.
Low-water control calibration
Correct Answer
A. Blow-down instructionsExplanation
The most common cause of feeder or low-water fuel cut-off trouble is the operator's failure to observe the blow-down instructions. Blow-down instructions refer to the process of removing sediment or impurities from the fuel system by draining a small amount of water or fuel. Failure to follow these instructions can lead to blockages or build-up of contaminants in the system, affecting its performance and causing trouble with the feeder or low-water fuel cut-off.Rate this question:
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- 47.
A pump affects the pressure of a fluid or gas by?
- A.
Raising pressure
- B.
Reducing pressure
- C.
Regulating pressure
- D.
Stabilizing pressure
Correct Answer
A. Raising pressureExplanation
A pump affects the pressure of a fluid or gas by raising it. When a pump is activated, it creates a higher pressure in the system by increasing the energy of the fluid or gas. This is typically achieved by using mechanical force to push the fluid or gas into a confined space, which in turn increases the pressure. As a result, the pump is able to raise the pressure of the fluid or gas to the desired level for various applications such as pumping water to higher elevations or increasing the pressure in a hydraulic system.Rate this question:
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- 48.
One BTU is equal to ___ ft-lb of mechanical energy
- A.
78ft-lb
- B.
778ft-lb
- C.
2ft-lb
- D.
878ft-lb
Correct Answer
B. 778ft-lbExplanation
One BTU is equal to 778 ft-lb of mechanical energy. This means that if you convert one BTU of energy into mechanical energy, it would be equivalent to 778 ft-lb.Rate this question:
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- 49.
The steam boiler component used to lower the concentration of dissolved impurities in the boiler water is?
- A.
Blow-off connection
- B.
Deconcentrator
- C.
Feed connection
- D.
Sediment reduction valve
Correct Answer
A. Blow-off connectionExplanation
A blow-off connection is a steam boiler component that is used to lower the concentration of dissolved impurities in the boiler water. It allows for the removal of accumulated sediment and dissolved solids from the boiler, helping to maintain the water quality and prevent damage to the boiler system. By opening the blow-off connection, the impurities are discharged from the boiler, ensuring that the water remains clean and free from excessive contaminants.Rate this question:
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- 50.
The total amount of heat 1 lb of steam has as it leaves the boiler is 1200 Btu/lb. What is the equivalent in ft-lb
Correct Answer
933600Explanation
The equivalent in ft-lb can be calculated by multiplying the total amount of heat (1200 Btu/lb) by the conversion factor of 778. This conversion factor represents the number of ft-lb in one Btu. Therefore, the calculation would be 1200 Btu/lb * 778 ft-lb/Btu, resulting in 933600 ft-lb.Rate this question:
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Apr 14, 2024Quiz Edited by
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Feb 13, 2020Quiz Created by
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