Gotta Catch Em All!!! Flashcards

Question

A _______________ ____________ air handler unit operates at the rated capacity at all times. A. Variable Volume B. Constant Volume C. Single Zone D. Multi-Zone

Answer 1

B. Constant Volume 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.

Answer 2

B. 2% 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.

Answer 3

A. Moisture 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.

Answer 4

C. Manual reset; operating 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.

Answer 5

A. Adamson 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.

Answer 6

A. 10, 5, 15 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.

Answer 7

B. Outside Screw and Yolk 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.

Answer 8

B. Volute 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.

Answer 9

A. 39.87' To match the airflow area of a rectangular duct (26" x 48"), a round duct's area must be equal. Using the area of the rectangle, we calculate the diameter of a circle that would have the same area. The formula involves dividing the rectangular area by π and taking the square root, then doubling it for the diameter, resulting in approximately 39.87 inches.

Answer 10

C. Single Zone 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.

Answer 11

C. 1" 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.

Answer 12

A. Resistance & electrode 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.

Answer 13

B. Latent Heat of vaporization 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.

Answer 14

A. Soot Blowers 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.

Answer 15

B. Hydrazine 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.

Answer 16

C. 160PSI, 250Deg.F 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.

Answer 17

A. Bagasse 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

Answer 18

C. Creep 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.

Answer 19

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

Answer 20

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

Answer 21

D. Multi Zone 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.

Answer 22

D. Steam, soda ash 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.

Answer 23

D. 18,840 Number 4 fuel oil has 18,840 BTU's per pound.

Answer 24

C. Reground, tightened 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.

Answer 25

C. Calcium, magnesium 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.

Answer 26

A. 10-20 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.

Answer 27

D. Sulfites Permanently hard water is water that contains large quantities of calcium and magnesium sulfites. Sulfites are compounds that can contribute to water hardness and can form insoluble precipitates with calcium and magnesium ions. These precipitates can cause scale buildup in pipes and appliances, reducing their efficiency and lifespan.

Answer 28

C. Bicarbonate Temporary hard water is water that contains large quantities of calcium and magnesium bicarbonate. When temporary hard water is heated or boiled, the bicarbonate ions decompose, resulting in the formation of insoluble carbonates. This causes the formation of scale or deposits on surfaces, such as in kettles or pipes. Temporary hard water is water that contains large quantities of calcium and magnesium

Answer 29

D. Box header A box header is a type of heat exchanger that is constructed of flat plates, specifically a tube sheet and tube cap sheet. This type of heat exchanger is commonly used in industrial applications to transfer heat between fluids. The box header design allows for efficient heat transfer due to the large surface area provided by the flat plates. A box header is a type of heat exchanger that is constructed of flat plates, specifically a tube sheet and tube cap sheet. This type of heat exchanger is commonly used in industrial applications to transfer heat between

Answer 30

D. 10-30 The correct answer is 10-30. This range represents the percentage of excess air required to burn natural gas, fuel oil, or pulverized coal. Excess air is the amount of air supplied to the combustion process above the theoretical amount required for complete combustion. A range of 10-30% ensures efficient and complete combustion while minimizing emissions.

Answer 31

A. 2,861.325 cu" The volume of water displaced with each stroke of the plunger can be calculated using the formula for the volume of a cylinder, which is V = πr²h. In this case, the diameter of the cylinder is given as 18", so the radius is half of that, which is 9". The length of the cylinder is given as 15". The plunger stroke is given as ¾ of the length of the cylinder, which is 15" x ¾ = 11.25". Using these values, we can calculate the volume as V = π(9²)(11.25) = 2,861.325 cu".

Answer 32

A. 77.8% To calculate boiler efficiency indirectly: Input: Calculate heat input from natural gas. Output: Determine heat absorbed by water using boiler horsepower. Losses: Calculate heat lost in flue gas. Efficiency: Use formula Efficiency = (1 - Losses/Input) × 100. Given values yield an efficiency of 77.8%.

Answer 33

B. 122 The pressure gauge installed 30 feet below the boiler drum reads 135 psi. However, the actual pressure on the boiler would be slightly lower due to the hydrostatic pressure caused by the weight of the water column above the gauge. The hydrostatic pressure increases by 0.433 psi for every foot of water depth. Since the gauge is 30 feet below the drum, the hydrostatic pressure would be 13 psi (30 feet x 0.433 psi/ft). Therefore, the actual pressure on the boiler would be 135 psi - 13 psi = 122 psi.

Answer 34

C. Heating surface, brick work, install The economic boiler has more heating surface per square foot of floor space, which means it can produce more steam. It also requires less brick work, making it easier to install and maintain. The economic boiler has more heating surface per square foot of floor space, which means it can produce

Answer 35

Bituminous, 550 Coal gas is produced using the volatile matter from bituminous coal, and has a heating value of 550 BTU's per cubic foot. Coal gas is produced using the volatile matter from bituminous coal, and has a heating value of 550 BTU

Answer 36

A. Gasoline, 2500, 3200 Butane and propane are produced from the manufacturing of gasoline. Propane has a heating value of 2500 BTU's per cubic foot, while butane has a heating value of about 3200 BTU's.

Answer 37

3/4", 4 1/2" The pressure relief valve on a hot water boiler must be at least 3/4" in diameter to ensure proper functioning and prevent excessive pressure buildup. It should also not exceed 4 1/2" in diameter to avoid any potential issues or restrictions in the system.

Answer 38

B. White The color of the cylinder containing R-12 is white before 2020.

Answer 39

B. Temporary Calcium and magnesium bicarbonate produce temporary hardness. Temporary hardness refers to the presence of dissolved calcium and magnesium bicarbonate ions in water, which can cause scale buildup on surfaces and reduce the effectiveness of soaps and detergents. This type of hardness can be easily removed by boiling the water or using a water softener.

Answer 40

C. Decrease, increase The presence of scale on the boiler tubes will cause a decrease in the boilers efficiency, as the scale acts as an insulator and reduces heat transfer. This decrease in efficiency will result in an increase in the temperature on the boiler tubes, as the heat is not being effectively transferred away.

Answer 41

A. Sulfurous acid When sulfur in the soot combines with moisture from condensation, it forms sulfurous acid. This reaction occurs when the sulfur in the soot reacts with water vapor in the air, resulting in the formation of sulfurous acid. Sulfurous acid is a weak acid that is commonly found in polluted air and can contribute to acid rain.

Answer 42

C. Light Green

Answer 43

A. Colloidal; 0.20 A colloidal is a gelatin-like substance that has very small particles in suspension. These particles are usually less than 0.20 microns in size.

Answer 44

A. Membrane Welding a flat strip of metal between the waterwall tubes is known as membrane wall construction. This type of construction involves creating a continuous, sealed membrane of metal that separates the water and steam from the combustion gases in a boiler. The membrane wall construction helps to improve the efficiency and safety of the boiler by providing a strong and reliable barrier between the different components.

Answer 45

B. Foaming Foaming is the correct answer because when the boiler water has a high level of solids, steam bubbles can get trapped below the water line, resulting in water level fluctuation. This phenomenon is known as foaming.

Answer 46

A. Carryover Carryover is the term used to describe the situation when water or impurities are carried out of the boiler along with the steam. This can happen due to factors such as high steam velocities, inadequate separation equipment, or excessive boiler water levels. Carryover can lead to various problems, including damage to downstream equipment, reduced steam quality, and decreased efficiency of the system.

Answer 47

C. Light gray The color of the cylinder containing R-123 is light gray before 2020.

Answer 48

Air When there is too much air present in a combustion process, it can cause incomplete burning of the fuel. This incomplete burning produces dense, white smoke.

Answer 49

Waterwalls Waterwalls consist of relatively close-spaced vertical tubes forming the four walls of the furnace. These tubes are designed to absorb heat from the combustion process and transfer it to the surrounding water, creating steam. Waterwalls are an important component in boilers and furnaces as they help in the efficient transfer of heat and ensure the proper functioning of the system.

Answer 50

Internal inspection The correct answer is internal inspection. The reason for this is that the shell of the HRT is exposed to the fire, which can cause damage such as scale, bulging, and blisters. To ensure the safety and proper functioning of the HRT, a careful internal inspection is necessary. This inspection allows for the identification of any potential issues or damage that may have occurred due to the exposure to fire. By conducting regular internal inspections, any problems

Answer 51

Slip Slip refers to the leaking that occurs inside a centrifugal pump from the discharge to the suction. It is a common issue in centrifugal pumps where a small amount of fluid leaks back from the high-pressure side to the low-pressure side. This can happen due to various reasons such as worn-out seals, damaged impeller, or excessive pressure. Slip can affect the efficiency and performance of the pump, and it needs to be addressed to prevent any further damage or loss of fluid.

Answer 52

Light blue The color of the cylinder containing R-134a is light blue before 2020.

Answer 53

17.1; 7,000 One grain is equal to 17.1 parts per million. Therefore, 7,000 grains equals one pound.

Answer 54

Alarm whistle The correct answer is "alarm whistle." An alarm whistle mounted on the Water Column will sound an alarm if the water level is too high or too low. This type of whistle is designed to alert individuals nearby when there is an issue with the water level, ensuring prompt action can be taken to address the problem.

Answer 55

Manometer A manometer is a U-tube draft gauge used to measure the differential pressure between two points. It consists of a U-shaped tube partially filled with a liquid, such as mercury or water. The pressure difference between the two points causes the liquid to rise or fall in one side of the tube, indicating the pressure difference. Manometers are commonly used in various applications, such as measuring gas pressure, airflow, and fluid levels.

Answer 56

Pinkish red The cylinder containing R-401A refrigerant is colored pinkish red. The pinkish red color is used to identify R-401A, which is a type of hydrofluorocarbon (HFC) refrigerant. This color-coding system is important in the refrigeration industry as it helps technicians, engineers, and other professionals to quickly and accurately identify the refrigerant being used.

Answer 57

Bottom connection If there is an obstruction in the bottom connection to the water column, it will prevent the water from flowing freely. As a result, when a gauge glass blow down is performed, the water level in the gauge glass will rise slowly instead of quickly decreasing. This is because the obstruction hinders the water from being discharged efficiently, causing a delay in the water level adjustment in the gauge glass.

Answer 58

58 A black liquor boiler requires a high concentration of solids in the liquor in order to sustain combustion. The correct answer is 58% because this is the percentage of solids that is necessary for the boiler to function properly.

Answer 59

Pound, degree, Fahrenheit A British thermal unit (BTU) is a unit of measurement used to quantify the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

Answer 60

Desuperheater A desuperheater is a device used to reduce the temperature of superheated steam to a lower desired temperature. It achieves this by injecting a coolant or a liquid into the superheated steam, which absorbs the excess heat and cools down the steam. This process is commonly used in industrial applications where the temperature of the steam needs to be controlled for various purposes, such as preventing damage to equipment or improving the efficiency of a system.

Answer 61

Condenser The condenser is responsible for rejecting the heat from the refrigeration system. It is a component that helps in the cooling process by transferring heat from the refrigerant to the surrounding environment. This is done by condensing the refrigerant vapor into a liquid state, releasing heat in the process.

Answer 62

Rose Refrigerant cylinders, such as those containing R410A, follow a specific color-coding system to facilitate easy identification and to prevent mishandling. For R410A, a widely used refrigerant in air conditioning systems, the cylinder is colored rose. This standardization of colors helps technicians quickly recognize different types of refrigerants during installation or maintenance procedures. The rose color specifically helps in distinguishing R410A from other refrigerants which may have similar applications but different environmental impacts and handling requirements. Proper identification ensures safe usage, compliance with regulations, and efficient system performance.

Answer 63

Evaporator The evaporator is the component in the refrigeration system that absorbs heat from the space. As the refrigerant passes through the evaporator, it evaporates and absorbs heat from the surrounding air or space, causing the temperature to decrease. This cooled refrigerant is then sent to the compressor to be pressurized and circulated back into the system.

Answer 64

Sodium sulfite Sodium sulfite is used to internally remove oxygen from the boiler.

Answer 65

Carbon, hydrogen, sulfur The chief heat producing elements in fuels are carbon, hydrogen, and sulfur. These elements have high energy content and when they undergo combustion, they release a significant amount of heat energy. Carbon and hydrogen are present in most organic compounds, which are commonly found in fuels such as coal, oil, and natural gas. Sulfur is also present in some fuels, and its combustion contributes to the heat production. Therefore, carbon, hydrogen, and sulfur are the primary elements responsible for the heat generation in fuels.

Answer 66

Blowdown Blowdown is the process of bleeding a portion of the water to remove suspended solids. This is typically done in industrial settings, such as power plants or boilers, to maintain the quality of the water and prevent buildup of impurities. By removing the suspended solids through blowdown, the water can be kept clean and the equipment can operate more efficiently.

Answer 67

40 The pressure of water decreases with increasing height due to the gravitational force acting on it. This decrease in pressure is approximately 0.433 psi per foot of height. Therefore, for a building that is 185 feet tall, the decrease in pressure would be 185 multiplied by 0.433 psi. Calculating this, we get approximately 80 psi. So, the city water pressure on the top floor of the building would be 120 psi minus 80 psi, which equals 40 psi.

Answer 68

Bottom blowdown The correct answer is "bottom blowdown." On HRT boilers, the shell is pitched 1 to 2 inches towards the back of the boiler to produce a more effective bottom blowdown of the boiler. This means that any sediment or impurities that settle at the bottom of the boiler can be easily drained and removed through the bottom blowdown process. This helps to maintain the efficiency and performance of the boiler by preventing the buildup of harmful deposits.

Answer 69

Saturated A solution is said to be saturated when it has reached its maximum capacity to dissolve any more impurities. In other words, it cannot dissolve any additional solute at a given temperature and pressure. A solution is said to be saturated when it has reached its maximum capacity to dissolve any more impurities. In other words, it cannot dissolve any

Answer 70

Saturated Water at its boiling point is considered a saturated liquid because at this temperature, it is in equilibrium with its vapor phase. This means that the liquid and vapor phases coexist and the liquid is saturated with vapor molecules. Any additional heat added to the system will cause the liquid to transition into a vapor phase.

Answer 71

Boiler efficiency The correct answer is "boiler efficiency." Boiler efficiency refers to the ratio of the heat output from the boiler to the heat input into the boiler. It is a measure of how effectively the boiler converts fuel into useful heat energy. A higher boiler efficiency indicates that the boiler is able to extract more heat from the fuel, resulting in lower fuel consumption and reduced energy waste.

Answer 72

Overheating Scale accumulation on the waterside of a firetube boiler can lead to overheating. When scale builds up on the boiler tubes, it acts as an insulator, preventing efficient heat transfer. This can cause the tubes to overheat, leading to potential damage and reduced efficiency of the boiler. Overheating can also result in the tubes becoming weakened and more prone to failure, posing a safety risk. Therefore, it is important to regularly clean and remove scale from the waterside of a firetube boiler to prevent overheating and maintain optimal performance.

Answer 73

34.5 A boiler horsepower is a unit of measurement used to indicate the rate at which a boiler can produce steam. In this context, it refers to the evaporation of steam into dry saturated steam. The answer of 34.5 pounds per hour indicates that a boiler with one horsepower can produce 34.5 pounds of dry saturated steam per hour when the water temperature is at 212°F.

Answer 74

Visible light Rectifying phototubes and lead sulfide phototubes are both types of photodetectors that can sense and detect light. In the context of the question, they are used to prove the presence of a flame in the boiler. Since flames emit visible light, these phototubes are able to detect and sense this visible light, indicating the presence of a flame. Therefore, the correct answer is visible light.

Answer 75

146,000; 18,840 #4 fuel oil has 146,000 BTUs per gallon and 18,840 BTUs per pound.

Answer 76

2,861.325 cu" The volume of water displaced with each stroke of the plunger can be calculated using the formula for the volume of a cylinder, which is V = πr²h. In this case, the diameter of the cylinder is given as 18", so the radius is half of that, which is 9". The length of the cylinder is given as 15". The plunger stroke is given as ¾ of the length of the cylinder, which is 15" x ¾ = 11.25". Using these values, we can calculate the volume as V = π(9²)(11.25) = 2,861.325 cu".

Answer 77

Amines Amines are added to the boiler to prevent steam line and condensate line corrosion. These chemicals are used because they will boil-off with the steam.

Answer 78

Carbon monoxide Carbon monoxide is produced during incomplete combustion, where there is insufficient oxygen available to fully burn the fuel. The presence of carbon monoxide in the flue gas is therefore an indication that the combustion process was not complete. Incomplete combustion can lead to the release of harmful pollutants and can also result in lower energy efficiency.

Answer 79

Guide vanes A turbine pump uses guide vanes to convert velocity to pressure energy. Guide vanes are stationary vanes that direct the flow of fluid into the impeller, which then converts the velocity of the fluid into pressure energy. The guide vanes help to control and direct the flow of fluid, ensuring efficient conversion of velocity to pressure.

Answer 80

Priming Priming is the correct answer because when water is entrained in the steam due to high steam flow rates, it is referred to as priming. Priming occurs when water droplets are carried along with the steam and can cause damage to equipment and decrease system efficiency.

Answer 81

Fixed carbon Anthracite coal is known for its high percentage of fixed carbon. Fixed carbon refers to the carbon content in coal that remains after volatile matter and moisture have been removed. This high carbon content contributes to the coal's heating potential and makes it a valuable fuel source.

Answer 82

Contact In conduction, the transfer of heat occurs due to direct contact between two materials. When two objects are in contact, heat energy is transferred from the hotter object to the colder object through molecular collisions. This process continues until both objects reach thermal equilibrium, with the heat evenly distributed between them. Therefore, contact is the correct answer as it accurately describes the mechanism of heat transfer in conduction.

Answer 83

50 The percentage of excess air required to burn coal is about 50 percent. Excess air is the amount of air supplied to a combustion process that exceeds the theoretical requirement for complete combustion. In the case of burning coal, a certain amount of excess air is necessary to ensure complete combustion and prevent the formation of harmful byproducts such as carbon monoxide. A value of 50 percent indicates that half of the air supplied is in excess of what is needed for complete combustion.

Answer 84

Proximate analysis Proximate analysis is a method used to determine the composition of coal by testing its moisture, volatile matter, fixed carbon, and ash content. This analysis provides important information about the quality and potential uses of the coal. It helps in understanding its heating value, combustion characteristics, and suitability for different applications. Therefore, the correct answer for this question is proximate analysis.

Answer 85

Refractory In a dry back scotch marine boiler, the hot gases from the furnace enter a combustion chamber. This combustion chamber is lined with refractory material. Refractory is a type of heat-resistant material that can withstand high temperatures without melting or deforming. It is used in boilers to protect the surrounding structure from the extreme heat generated by the combustion process. The refractory lining helps to maintain the efficiency and durability of the boiler by preventing heat loss and minimizing damage to the surrounding components.

Answer 86

Overheating The low water fuel cut-off is designed to shut off the fuel supply to the burner when the water level in the boiler drops below a safe level. This prevents overheating of the boiler, which can cause serious damage.

Answer 87

Oil heaters Oil heaters are a potential source of oil contamination of the water side of a boiler. This is because oil heaters are used to heat oil, and if there is any leakage or malfunction in the oil heating system, it can result in oil entering the water side of the boiler. This can lead to contamination of the boiler water, which can negatively impact the efficiency and performance of the boiler. Therefore, it is important to regularly inspect and maintain oil heaters to prevent any oil contamination issues.

Answer 88

Compressor The compressor is considered the heart of the refrigeration system because it plays a crucial role in the cycle. It is responsible for compressing the refrigerant gas, raising its temperature and pressure. This compressed gas then moves to the condenser where it releases heat and transforms into a high-pressure liquid. Without the compressor, the refrigeration cycle would not be able to function properly as it is responsible for circulating the refrigerant and maintaining the necessary pressure levels.

Answer 89

33,475 One boiler horsepower is equivalent to 33,475 BTU's per hour output.

Answer 90

Convection Convection is the transfer of heat from a liquid flowing over the surface of a body. This process occurs when the heated liquid comes into contact with the surface, absorbs the heat, and then carries it away as it flows. The movement of the liquid helps to distribute the heat evenly and efficiently.

Answer 91

H A low pressure steam boiler must have an ASME H stamp. This indicates that the boiler is designed and constructed in accordance with the ASME Boiler and Pressure Vessel Code Section IV, which specifically covers low pressure steam heating boilers. The H stamp ensures that the boiler meets the necessary safety standards and regulations for its intended use.

Answer 92

Liquid The evaporator receives medium temperature liquid refrigerant because the purpose of the evaporator is to absorb heat from the surrounding air or water, causing the refrigerant to evaporate and turn into a gas. This heat absorption process is more efficient when the refrigerant is in its liquid state.

Answer 93

Turn down ration The turn down ratio refers to the ratio between the maximum and minimum fuel input rates. This ratio is used to measure the flexibility of a fuel system, as it determines the range of fuel flow that can be achieved. A higher turn down ratio indicates a greater range of fuel flow, allowing for more precise control of the combustion process. Therefore, the turn down ratio is the correct term for the given description.

Answer 94

S A high pressure steam boiler must have an ASME "S" stamp. The ASME "S" stamp indicates that the boiler has been designed, constructed, and inspected in accordance with the ASME Boiler and Pressure Vessel Code Section I, which specifically covers power boilers. This stamp ensures that the boiler meets the necessary safety and quality standards for high pressure steam applications.

Answer 95

Forced convection When a pump is used to circulate water through a heating system, it creates forced convection. Forced convection refers to the movement of fluid (in this case, water) due to an external force (the pump). The pump forces the water to circulate through the heating system, allowing it to transfer heat and warm the space.

Answer 96

Sulfites Permanently hard water is water that contains large quantities of calcium and magnesium sulfites. Sulfites are compounds that can contribute to water hardness and can form insoluble precipitates with calcium and magnesium ions. These precipitates can cause scale buildup in pipes and appliances, reducing their efficiency and lifespan.

Answer 97

Reduced, velocity, heat, transfer In order to maintain constant heat transfer, it is necessary to reduce the velocity of the fluid. This is because reducing the velocity allows for more time for heat exchange to occur between the fluid and the tubes. By reducing the velocity, the fluid can spend more time in contact with the tubes, increasing the efficiency of heat transfer. Therefore, reducing the velocity is necessary to maintain constant heat transfer.

Answer 98

Steam valve Water hammer is caused by quickly opening a steam valve. When a steam valve is rapidly opened, it causes a sudden change in pressure and temperature in the connected piping. This sudden change can lead to vibration, noise, or even pipe rupture.

Answer 99

Tube ends Fire tube boilers are likely to leak due to cracking, burning, and corrosion of the tube ends. The tube ends are the parts of the boiler where the tubes connect to the boiler shell. Over time, the intense heat and pressure in the boiler can cause the tube ends to become weakened and damaged. This can lead to cracks, burning, and corrosion, which can result in leaks in the boiler. Regular maintenance and inspection of the tube ends are necessary to prevent these issues and ensure the safe and efficient operation of the boiler.

Answer 100

#1 fuel oil Light domestic fuel oil is commonly referred to as #1 fuel oil. This type of fuel oil is lighter in viscosity and has a lower sulfur content compared to other fuel oils. It is commonly used for residential heating purposes and is also known as "kerosene" or "home heating oil".

Answer 101

Resistance Temperature Sensor A temperature sensor that measures the resistance of a platinum wire at different temperatures is called a Resistance Temperature Sensor. This type of sensor relies on the principle that the resistance of a metal, such as platinum, changes with temperature. By measuring the resistance of the wire, the sensor can accurately determine the temperature.

Answer 102

Box header, sinous header The early watertube boilers had straight tubes that were suspended over a furnace. These tubes were rolled into two types of headers: box headers and sinuous headers.

Answer 103

Non-destructive testing Non-destructive testing refers to a method of evaluating the quality and integrity of a material without causing any physical or chemical changes to it. This technique allows for the examination of the material's soundness without causing any damage or alteration. It is commonly used to detect defects, flaws, or abnormalities in various materials, such as metals, composites, and concrete, without compromising their structural integrity. Visual inspection, indirect sampling, and accumulation testing do not accurately describe the process of testing the material without affecting it physically or chemically.

Answer 104

Flash point The flash point is the temperature at which fuel oil will give off vapor that will ignite when exposed to an open flame.

Answer 105

Hydrochloric Hydrochloric acid is commonly used to dissolve scale deposits during an acid cleaning process. It is a strong acid that can effectively break down and remove mineral deposits such as calcium carbonate and limescale. Hydrochloric acid is preferred for this purpose due to its high reactivity and ability to dissolve various types of scales. Additionally, it is readily available and cost-effective, making it a popular choice for acid cleaning applications.

Answer 106

19 The correct answer is 19. Prior to entering a confined space, it is important to ensure that there is a sufficient amount of oxygen present. The minimum amount of oxygen required for safe entry into a confined space is typically around 19 percent. Oxygen levels below this can be dangerous and may lead to asphyxiation or other health hazards. Therefore, it is crucial to monitor and confirm the oxygen levels before entering a confined space to ensure the safety of individuals.