BOILERS EXAM 2024 | ALL QUESTIONS AND CORRECT ANSWERS | ALREADY GRADED A+ | LATEST VERSION, Exams of Boilers and Welding

Download BOILERS EXAM 2024 | ALL QUESTIONS AND CORRECT ANSWERS | ALREADY GRADED A+ | LATEST VERSION and more Exams Boilers and Welding in PDF only on Docsity! BOILERS EXAM 2024 | ALL QUESTIONS AND CORRECT ANSWERS | ALREADY GRADED A+ | LATEST VERSION | JUST RELEASED The ASME code will allow an automatic nonreturn valve to be used in place of one of the main steam stop valves. If a nonreturn valve is used, it must be ___. ------CORRECT ANSWER---------------located between the main steam stop valve and boiler shell When cutting a boiler equipped with hand-operated main steam stop valves in on-line, the steam pressure on the incoming boiler ___. ------CORRECT ANSWER---------------should be slightly lower than line pressure A ___ valve should be used as the main steam stop valve. ------CORRECT ANSWER---------------gate A steam separator is used to improve the quality of steam in order to ___. - -----CORRECT ANSWER---------------prevent damage from water hammer Hydrostatic pressure is caused by ___. ------CORRECT ANSWER------------ ---the weight of a column of water A(n) ___ is located at the lowest part of the water side of a firetube boiler or the mud drum of a watertube boiler so that sludge and sediment can be removed from the bottom of the boiler. ------CORRECT ANSWER------------- --bottom blowdown valve A steam pressure gauge must be protected by a(n) ___ to prevent steam from damaging the gauge. ------CORRECT ANSWER---------------steam siphon Saturated steam is steam that is ___. ------CORRECT ANSWER--------------- in equilibrium with water at the same temperature and pressure When steam is superheated, the temperature ___. ------CORRECT ANSWER---------------increases with no change in pressure Superheater tubes are protected from warping or burning out by the ___. --- ---CORRECT ANSWER---------------continuous flow of steam Steam impinging on boiler tubes would ___. ------CORRECT ANSWER------ ---------cause erosion of the lines and fittings Steam quality is the ratio of dry steam to the total amount of ___. ------ CORRECT ANSWER---------------water evaporated A(n) ___ may be a simple bend or a set of elbows that allow the pipe to move slightly. ------CORRECT ANSWER---------------expansion bend The flow of steam through a superheater should never be less than ___% of boiler capacity. ------CORRECT ANSWER---------------25 A(n) ___ is used in larger steam boiler plants where there are many sources from which condensate returns to the boiler room. ------CORRECT ANSWER---------------condensate surge tank Because of the large volume of water, the boiler type most likely to cause a boiler explosion is a ___ boiler. ------CORRECT ANSWER--------------- firetube The part of a boiler with the heat and gases of combustion on one side and water on the other side is known as the ___ surface. ------CORRECT ANSWER---------------heating ___ is the pressure at which the density of water and steam are the same. - -----CORRECT ANSWER---------------Critical pressure An electric boiler produces heat using electrodes or ___. ------CORRECT ANSWER---------------resistance coils Boiler horsepower (BHP) is the amount of energy equal to the evaporation of ___ lb/hr of water from and at a feedwater temperature of 212°F. ------ CORRECT ANSWER---------------34.5 A high pressure steam boiler operates at a steam pressure of more than ___ psi. ------CORRECT ANSWER---------------15 A ___ results in a higher boiling point for water in a boiler. ------CORRECT ANSWER---------------higher steam pressure A(n) ___ is a boiler that uses heat recovered from a hot gas stream, such as hot exhaust gases from a kiln or from a gas turbine. ------CORRECT ANSWER---------------heat recovery steam generator (HRSG) A ___ is the lowest part of the water side of a watertube boiler. ------ CORRECT ANSWER---------------mud drum By increasing the number of passes and the number of fire tubes, water can absorb more heat and ___ increases. ------CORRECT ANSWER--------- ------thermal efficiency The steam drum of watertube boilers is dished (concave) to eliminate the need for ___. ------CORRECT ANSWER---------------stays ___ stress occurs when two forces of equal intensity act from opposite directions and push toward the center of an object. ------CORRECT ANSWER---------------Compressive ___ are used to direct the gases of combustion so that they come in close contact with the boiler heating surface. ------CORRECT ANSWER------------- --Baffles A ___ is a set of tubes that is placed in the furnace area of watertube boilers and used to increase the heating surface of boilers and the service life of refractory. ------CORRECT ANSWER---------------waterwall A ___ boiler comes completely assembled, with its own pressure vessel, burner, draft fans, and fuel train. ------CORRECT ANSWER--------------- package Boiler plates and stays are subjected to ___ stress. ------CORRECT ANSWER---------------tensile ___ are used to prevent bulging in boilers. ------CORRECT ANSWER-------- -------Through stays A ___ converts the energy from the expansion of high-pressure steam into the mechanical energy of rotation. ------CORRECT ANSWER--------------- turbine A ___ is a device that converts mechanical energy into electrical energy. --- ---CORRECT ANSWER---------------generator Cogeneration is the process of ___ and then using the waste heat for heating buildings, providing process heat, or further electrical generation. -- ----CORRECT ANSWER---------------generating electricity Feedwater can be pumped through a ___ where it is heated to a relatively high temperature by the gases of combustion. ------CORRECT ANSWER--- ------------closed feedwater heater In the deaerator tank, a ___ to add makeup water to the deaerator tank to compensate for the condensate lost. ------CORRECT ANSWER--------------- float opens a feed valve A shutoff valve is used when ___. ------CORRECT ANSWER--------------- making repairs On larger watertube boilers, a(n) ___ can heat the feedwater by using gases of combustion before the feedwater enters the boiler. ------ CORRECT ANSWER---------------economizer Once fuel oil reaches the burner, it is the function of the burner to ___ the oil so it can mix with air and burn. ------CORRECT ANSWER--------------- atomize In a low-pressure gas system, the zero gas governor reduces the pressure of the gas to ___ psi. ------CORRECT ANSWER---------------0 In a low-pressure gas system, the air and gas mixture in the furnace is ignited by the ___. ------CORRECT ANSWER---------------pilot Modern coal plants use ___ coal that is blown into the combustion chamber where it burns in suspension. ------CORRECT ANSWER--------------- pulverized ___ valves are typically slow-opening, fast-closing, hydraulic-electric valves and should have an internal proof-of-closure switch. ------CORRECT ANSWER---------------Safety shutoff A(n) ___ is used to clean fuel oil before it goes to a burner. ------CORRECT ANSWER---------------strainer Stop valves isolate a tank when ___. ------CORRECT ANSWER--------------- it is not in use Most steam plants that use No. ___ fuel oil have two tanks. ------CORRECT ANSWER---------------6 In a basic pulverized coal system, the coal ___ stores the coal before it flows onto the coal conveyor. ------CORRECT ANSWER---------------bunker ___ draft results from temperature differences between air and gases of combustion and is produced with a stack only. ------CORRECT ANSWER--- ------------Natural The amount of draft in a(n) ___ draft system can be increased by a taller stack. ------CORRECT ANSWER---------------natural ___ draft systems are often used in large steam plants such as those in central heating plants, large industrial boilers, or utility boilers. ------ CORRECT ANSWER---------------Combination In combination draft systems, ambient air is drawn through the ___ into the forced draft fan and is discharged into the boiler where combustion occurs. ------CORRECT ANSWER---------------preheater CHAPTER 3 ------CORRECT ANSWER--------------- The setting or adjusting of a safety valve should only be done by a ___. ---- --CORRECT ANSWER---------------qualified person who is familiar with the construction and operation of the safety valve The ___ is the operating pressure of a boiler as determined by the design and construction of the boiler in conformance with the ASME Code. ------ CORRECT ANSWER---------------maximum allowable working pressure The safety valve on a boiler must be capable of discharging all the steam the boiler can generate without the pressure increasing more than ___ above the MAWP. ------CORRECT ANSWER---------------6% A(n) ___ test is a safety valve test performed to determine if a safety valve opens at the correct pressure. ------CORRECT ANSWER---------------pop CHAPTER 5 ------CORRECT ANSWER--------------- The main purpose of a water column is to ___. ------CORRECT ANSWER-- -------------reduce turbulence in the gauge glass to get a more accurate reading of the water level in the boiler A low-water fuel cutoff ___ in the event of a low-water condition. ------ CORRECT ANSWER---------------secures the burner The water column and gauge glass should be blown down at least ___ or whenever the water level is in doubt. ------CORRECT ANSWER--------------- once every shift An auxiliary low-water fuel cutoff is installed ___. ------CORRECT ANSWER---------------slightly below the primary low-water fuel cutoff ___ is a process in which the water level in a boiler momentarily rises with an increase in steam demand. ------CORRECT ANSWER---------------Swell A two-element feedwater regulator controls the feedwater by measuring the water level in the boiler and the ___. ------CORRECT ANSWER--------------- steam flow out of the boiler A ___-type low-water fuel cutoff consists of a cylindrical object that is immersed in the water and connected to a spring or torsion device that twists in response to the weight of the cylinder. ------CORRECT ANSWER-- -------------displacer Cast iron can be used for pressures up to ___ psi. ------CORRECT ANSWER---------------250 A one-element feedwater regulator is a feedwater regulator that regulates the amount of feedwater by measuring the ___. ------CORRECT ANSWER- --------------water level in the boiler ___ are effective when there are sudden fluctuations in the steam load and in boilers equipped with economizers where there is a considerable drop in feedwater pressure. ------CORRECT ANSWER---------------Three-element feedwater regulators A(n) ___ heats feedwater by passing it through a heat exchanger placed in the path of the gases of combustion. ------CORRECT ANSWER--------------- economizer As feedwater is heated, scale-forming salts start to settle out at about ___°F. ------CORRECT ANSWER---------------150 A(n) ___ feedwater heater is a feedwater heater in which steam and feedwater mix with each other. ------CORRECT ANSWER---------------open With a(n) ___, heat that would normally be lost up the stack is reclaimed to preheat the feedwater. ------CORRECT ANSWER---------------economizer A closed feedwater heater is normally equipped with a ___ to protect the shell from excessive pressure. ------CORRECT ANSWER---------------safety valve A high water level in a feedwater heater can allow water to enter the steam or condensate lines and cause ___. ------CORRECT ANSWER--------------- water hammer Soot retards heat transfer because it ___. ------CORRECT ANSWER--------- ------insulates the surface of the economizer The theory of operation of a centrifugal pump is that the centrifugal force of a rotating element ___. ------CORRECT ANSWER---------------is converted into pressure The feedwater stop valve on a feedwater line is located closest to the shell of the boiler so that the ___. ------CORRECT ANSWER---------------check valve can be repaired without taking the boiler off-line A variable-speed drive is a motor controller used to vary the ___ supplied to an AC motor in order to control its rotational speed. ------CORRECT ANSWER---------------electrical frequency and causing them to settle out of solution. ------CORRECT ANSWER--------- ------Coagulation An ion-exchange softener uses an ion-exchange ___ to exchange a sodium ion for an ion that causes hardness. ------CORRECT ANSWER------ ---------resin A lime-soda softener uses lime and soda ash to reduce dissolved ___, magnesium, and silica. ------CORRECT ANSWER---------------calcium A ___ is an internal element in some types of deaerators that condenses steam and uses the heat produced to warm the feedwater. ------CORRECT ANSWER---------------vent condenser A hot ___ softener is used above 212°F and is also known as a hot process water softener. ------CORRECT ANSWER---------------lime-soda A(n) ___ is a positively charged ion. ------CORRECT ANSWER--------------- cation Demineralization of makeup water is necessary for boilers operating above ___ psi. ------CORRECT ANSWER---------------1000 A(n) ___ is an ion-exchange conditioner that removes impurities from condensate. ------CORRECT ANSWER---------------condensate polisher A boiler operator is generally responsible for verifying that the water leaving a deaerator is free of ___. ------CORRECT ANSWER---------------oxygen ___ are generally added to boiler water to protect the condensate lines from carbonic acid. ------CORRECT ANSWER---------------Amines A ___ blowdown system includes a conductivity sensor inserted into the boiler water, a controller, and a modulating blowdown valve. ------ CORRECT ANSWER---------------concentration-controlled Sodium sulfite is added to feedwater to remove remaining ___ to prevent pitting of the boiler metal. ------CORRECT ANSWER---------------oxygen A ___ is a vented tank that cools blowdown water and steam to protect sewer lines. ------CORRECT ANSWER---------------blowdown tank A boiler should be blown down at least once every ___, regardless of the analysis results. ------CORRECT ANSWER---------------24 hr ___ blowdown is the process of removing water from a boiler near the NOWL to control the quantity of impurities in the remaining water or to remove a film of impurities on the surface of the water. ------CORRECT ANSWER---------------Surface ___ steam is the steam created when water at a high temperature experiences a sudden drop in pressure. ------CORRECT ANSWER----------- ----Flash A(n) ___ tank is a tank used with a continuous blowdown system to recover the flash steam from the water being removed during blowdown. ------ CORRECT ANSWER---------------flash CHAPTER 7 ------CORRECT ANSWER--------------- ___ specify leak detection and monitoring requirements for fuel oil tanks to ensure there is no ground or water contamination. ------CORRECT ANSWER---------------EPA regulations Soot blowers are mainly found on ___. ------CORRECT ANSWER------------- --watertube boilers With an air atomizing fuel oil burner, the mixture of air and fuel oil passes through a ___ that causes it to spin into the combustion chamber. ------ CORRECT ANSWER---------------register A ___ is installed after a fuel oil heater to protect against excessive fuel oil pressure. ------CORRECT ANSWER---------------safety relief valve A fluidized-bed boiler can burn coal with ___ content without requiring expensive flue-gas treatment. ------CORRECT ANSWER---------------high sulfur A(n) ___ feeds coal into a boiler in suspension and on a grate. ------ CORRECT ANSWER---------------spreader stoker ___ is noncombustible components of coal that melt and fuse together during combustion. ------CORRECT ANSWER---------------Clinker ___ is relatively small ash particles that are light enough to be suspended in a combustible gas stream and carried through a boiler. ------CORRECT ANSWER---------------Fly ash Coal is burned in suspension and requires a furnace temperature of approximately ___°F to achieve complete combustion. ------CORRECT ANSWER---------------3000 Spreader stokers operate with ___. ------CORRECT ANSWER---------------a very thin fuel bed CHAPTER 8 ------CORRECT ANSWER--------------- The viscosity of fuel oil is normally reported as the ___ viscosity. ------ CORRECT ANSWER---------------Saybolt A ___ is a unit used to measure the heat content of natural gas and is equal to 100,000 Btu. ------CORRECT ANSWER---------------therm ___ coal, commonly known as hard coal, contains a high percentage of fixed carbon and a low percentage of volatile matter. ------CORRECT ANSWER---------------Anthracite Natural gas is a combustible gas that consists mainly of ___ with small quantities of ethylene, hydrogen, and other gases. ------CORRECT ANSWER---------------methane No. ___ fuel normally needs to be preheated before use. ------CORRECT ANSWER---------------6 A British thermal unit (Btu) is a measurement of the quantity of heat required to raise the temperature of ___ of water by 1°F. ------CORRECT ANSWER---------------1 lb The fuel oils most commonly used in high pressure boilers include ___. ----- -CORRECT ANSWER---------------No. 2 and No. 6 ___ point is the lowest temperature at which a liquid will flow from one container to another. ------CORRECT ANSWER---------------Pour Coal rank refers to the ___ of coal. ------CORRECT ANSWER--------------- hardness ___ gas is gas produced by the biological breakdown of organic matter in the absence of oxygen. ------CORRECT ANSWER---------------Digester ___ combustion occurs when all the fuel is burned using a minimum amount of excess air. ------CORRECT ANSWER---------------Complete In combustion, fuel combines with the ___ in the air to form carbon dioxide, water, and traces of other compounds. ------CORRECT ANSWER------------- --oxygen The letter "M" in the acronym MATT stands for ___. ------CORRECT ANSWER---------------mixture Reducing excess air while still completely burning a fuel ___. ------ CORRECT ANSWER---------------decreases the heat lost to the atmosphere ___ air is air supplied to the boiler that is more than the theoretical amount of air needed for combustion. ------CORRECT ANSWER---------------Excess Oxygen trim is a control strategy used to adjust the ___ of a burner according to the results from a flue gas oxygen analyzer. ------CORRECT ANSWER---------------air-fuel ratio A variable-speed drive (VSD) is a motor controller used to vary the ___ of the electrical signal supplied to an AC motor in order to control its rotational speed. ------CORRECT ANSWER---------------frequency ___ control is used to stop and start a burner without any modulation of the flame. ------CORRECT ANSWER---------------ON/OFF A(n) ___ signal consists of binary (ON/OFF) signals in the form of low- voltage DC pulses sent over a network. ------CORRECT ANSWER------------ ---digital Cross-limited control increases safety by adding a linking system that ___ during load changes. ------CORRECT ANSWER---------------prevents the airflow from going too low for the amount of fuel flow A modulating control system is used to adjust the firing rate to a degree that is proportional to the ___. ------CORRECT ANSWER---------------steam load CHAPTER 10 ------CORRECT ANSWER--------------- Natural draft is controlled by ___. ------CORRECT ANSWER--------------- dampers ___ draft is produced by a blower supplying air to a furnace. ------ CORRECT ANSWER---------------Forced When using forced draft, the pressure inside the furnace is ___. ------ CORRECT ANSWER---------------more than atmospheric pressure Draft is the ___ through a boiler. ------CORRECT ANSWER---------------flow of air or gases of combustion A ___ is a chamber surrounding a burner assembly or coal stoker that allows pressurized air to enter the burner. ------CORRECT ANSWER--------- ------wind box The unit used to measure draft is ___. ------CORRECT ANSWER-------------- -in. WC Induced draft fans remove gases of combustion and prevent ___ from developing. ------CORRECT ANSWER---------------back pressure ___ are located at the outlet side of a boiler in the breeching. ------ CORRECT ANSWER---------------Outlet dampers Draft must be proportional to ___ for proper operation and efficient fuel consumption. ------CORRECT ANSWER---------------fuel flow An air heater uses heat from the gases of combustion to heat the ___. ------ CORRECT ANSWER---------------combustion air before it mixes with the fuel A VSD adjusts blower speed to maintain the correct amount of air ___ without wasting energy because of dampers that restrict flow. ------ CORRECT ANSWER---------------for the amount of fuel used The purpose of using an air heater is to improve efficiency by ___. ------ CORRECT ANSWER---------------preheating combustion air A ___ draft system typically consists of a forced draft fan, an air heater, a windbox under the chain grate, an economizer, and an induced draft fan. --- ---CORRECT ANSWER---------------chain grate stoker Cold air entering a furnace can cause ___ in the brickwork of a furnace. ---- --CORRECT ANSWER---------------spalling In a pulverized coal draft system, the air from the forced draft fan that flows to the air-tempering damper blends with ambient air to maintain an air temperature of about ___°F. ------CORRECT ANSWER---------------200