boiler exam study guide 2 1.1: When economizers are used to heat boiler feedwater, every 10°F rise in feedwater temperature is accompanied by a ___% savings in fuel. 2.1: According to the ASME Code, the minimum size pipe connecting the water column to the boiler is ___". 3.1 ½: The pressure applied on the boiler during a hydrostatic test is ___ times the MAWP. 4.1 ½: The range of a boiler pressure gauge must not be less than ___ times the safety valve setting. 5.1 ½ times the MAWP: When making a hydrostatic test on a boiler, the pressure is ___. 6.1 ½ to 2 times the safety valve setting: According to the ASME code, the suggested range of a boiler pressure gauge is ___. 7.2 ½: According to the ASME Code, the maximum size of the boiler bottom blowdown line is ___". 8.6: No. ___ fuel oil has the highest Btu content per gallon. 9.6: Boiler safety valve capacity must be such that the steam pressure can never go higher than ___% above the MAWP. 10.6% above the MAWP: With all of the safety valves popping, the b oiler pressure should not go higher than ___. 11.7: Neutral on the pH scale is ___. 12.10 to 11.5: The pH of the boiler water should be ___. 13.15 psi to 25 psi: When warming up a boiler during cold plant startup, the boiler vent should remain open until the steam pressure reaches approximately ___. 14.34.5: At a water temperature of 212°F, 1 BHP is equivalent to the evaporation of ___ lb of water/hour. 15.34.5: Boiler horsepower is the evaporation of ___ lb of water/hr from and at a feedwater temperature of 212°F. 16.100: If three boilers are connected to a common header and each boiler is at 100 psi, the master gauge on the header would read ___ psi. 17.100,000; therm: The Btu content of natural gas is ___ Btu per ___. 18.174.7: The absolute pressure of a steam boiler carrying 160 psig would be ___ psia. 19.500: According to the ASME Code, a b oiler that has more than ___ sq ft of heating surface must have two or more safety valves. 20.a blowdown tank: Sludge and sediment from the mud drum of a boiler are discharged into ___. 21.a broken baffle: A sudden increase in chimney temperature without a corresponding increase in steam demand indicates ___. 22.a dirty heating surface: A gradual increase in chimney temperature indicates ___. 23.a high: Viscosity is the internal resistance of a fluid to flow. No. 6 fuel oil has ___ viscosity. 24.a high furnace temperature: For the efficient combustion of pulverized coal, it is necessary to maintain ___. 25.a lower pressure than: The superheater header safety valve is set to pop at ___ the steam and water drum safety valves. 26.a minimal amount of excess air: Complete combustion is defined as burning all fuel using ___. 27.a mixture of water and steam: The middle try cock should b e mounted at the NOWL and, when operated, should blow ___.
28.a rise in chimney temperature: A br oken baffle in a watertube boiler causes ___. 29.above the feedwater pump on the suction side: An open feedwater heater is located ___. 30.accumulation: A(n) ___ test is used to test the relieving capacity of a safety valve. 31.acts as a flame f ailure control: An infrared scanner ___. 32.alkaline: Boiler water with a pH of 11 is ___. 33.allow the setting to cool: Before draining a boiler, the operator should ___. 34.an air- or water-driven turbine: Scale buildup in the tubes of watertube boiler can be removed by ___. 35.an internal furnace: A scotch marine boiler has ___. 36.Anthracite: ___ coal has the highest amount of fixed carbon. 37.as a secondary means of determining the water level: The try cocks on a water column are used ___. 38.at its lowest load: The best time to blow down a boiler is when it is ___. 39.at least once a shift: In most plants, the suggested operating procedure is to blow down the water column and gauge glass ___. 40.at the NOWL: The feedwater regulator element is located ___. 41.at the NOWL: The surface blowdown on a steam boiler is located ___. 42.atmospheric: In a balanced draft system, the pressure in the furnace is approximately ___. 43.atmospheric pressure: A barometer measures ___. 44.atomize the fuel oil completely: The function of the fuel oil burner is to ___. 45.below atmospheric: In a plant that uses forced draft, the pressure at the base of the chimney is ___ pressure. 46.between the feedwater pump and the boiler: A closed feedwater heater is located ___. 47.blow down the boiler: If water comes out of the top try cock, the boiler operator must ___. 48.boiler: An automatic nonreturn valve is used with a(n) ___. 49.boiler main steam line between the boiler and the main stop valve: An automatic nonreturn valve is found on the ___. 50.boiler setting is cool enough to enter the firebox: Boilers taken off-line for cleaning and inspection may be dumped (emptied) when the ___. 51.boiler; check valve: The boiler feedwater stop valve is between the ___ and ___. 52.boiler; chimney: The induced draft fan is located between the ___ and ___. 53.burn continually: The fire point of fuel oil is the minimum temperature at which the fuel oil will ___. 54.by hand or pressure: Safety valves on high pressure boilers can be tested ___. 55.chain grate: An ignition arch is used with a(n) ___ stoker 56.change scale-forming salts to a nonadhering sludge: Feedwater is treated chemically b efore it enters the boiler to ___. 57.closed: To start a turbine pump, the discharge valve should be ___. 58.closest to the boiler and followed b y the screw-type valve: On boilers that have both quickclosing and screw-type blowdown valves, the quick-closing valve must be located ___. 59.combustion efficiency: The Orsat analyzer is used to determine the ___. 60.complete: Carbon dioxide in the flue gas is a sign of ___ combustion. 61.condensation in the line: Water hammer in steam lines is caused by ___. 62.continuous blowdown: A safe maximum water concentration of contaminates in steam generators serving low makeup plants is maintained by ___. 63.corrosion: A deaerating feedwater heater removes noncondensable gases such as air, free oxygen, and CO2 from the feedwater that can cause ___. 64.dangerous to handle: Fuel oil with a low flash point is ___.
65.deadweight tester: Pressure gauges are calibrated with a(n) ___. 66.decreased: As fuel oil is heated, its viscosity is ___. 67.density of the smoke leaving the boiler: A Ringelmann chart in a steam generating plant is helpful in determining the ___. 68.determine smoke density: A Ringelmann test is used to ___. 69.difference in pressure between two points: A manometer measures ___. 70.dirty strainers: A high suction reading on the fuel oil pressure gauge indicates ___. 71.do not mix: In a closed feedwater heater, the steam and water ___. 72.Draft: ___ is the difference in pressure between two points of measurement that causes air or gases of combustion to flow. 73.dry pipe: To aid in the delivery of moisture-free steam, the steam leaves the steam and water drum through the ___. 74.establishes a steam flow through: The superheater drain ___ the superheater during startup and shutdown. 75.every 24 hours: According to the ASME Code, when no boiler water analysis is made the boiler should be blown down at least once ___. 76.excessive heat, corrosion, or freezing: The blowdown line must be protected from ___. 77.expanded and flared: The tubes in a straight-tube watertube boiler are ___ into drums, headers, or sheets to remain stationary. 78.F: T/F Absolute pressure is pressure below the atmospheric pressure. 79.F: T/F The Bourdon tube of a steam pressure gauge does not have to be protected. 80.F: T/F A steam pressure gauge is calibrated in pounds per square foot. 81.F: T/F Weighted lever-type safety valves can be used on steam boilers that operate at pressures not exceeding 50 psi. 82.F: T/F Excess air for combustion is indicated by testing for CO2 in the gases of combustion. 83.F: T/F The dry method of boiler lay-up requires the boiler to be opened and air to be circulated to keep the boiler drums and tubes dry. 84.F: T/F Chemical treatment of the boiler water is not necessary when laying a boiler up wet if the water has been deaerated. 85.F: T/F No. 6 fuel oil burns with a clean flame fl ame when it is not heated. 86.F: T/F A desuperheater is only used in low pressure steam plants. 87.F: T/F The forced and induced draft fans on a boiler are the same size and operate at the same speed. 88.F: T/F A pyrometer measures the amount of moisture in steam leaving a boiler. 89.F: T/F The size of a boiler tube is determined by the inside diameter of the tube. 90.F: T/F Superheating steam is impossible at l ow steam pressures. 91.F: T/F An adequate supply of air is the only thing needed for good combustion. 92.F: T/F All boilers are equipped with a water column. 93.F: T/F A flow meter integrator totalizes the temperature and pressure of steam. 94.F: T/F Boiler drum safety valves must open before the superheater safety valve to ensure a backflow. 95.F: T/F To control the flow of steam, the gate valve is opened half way. 96.F: T/F A globe valve offers less resistance to flow than a gate valve does. 97.F: T/F A therm of natural gas has 10,000 Btu. 98.F: T/F In a natural draft system, the lower draft reading is obtained at the furnace. 99.F: T/F A calorimeter measures excess air being used for combustion. 100.F: T/F The high and low water level alarm floats f loats are components of the boiler feedwater system.
101.F: T/F Boiler tube dimensions are based on the inside diameter of the tube. 102.F: T/F The bottom blowdown valves can be used to lower the b boiler oiler steam pressure. 103.F: T/F A high pressure cutoff control can take the place of a safety valve. 104.F: T/F Steam traps are only used on high-temperature hot water systems. 105.F: T/F It is unnecessary to blow down a boiler if proper feedwater treatment is used. 106.F: T/F Boiler corrosion cannot be prevented as long as water is in contact with metal. 107.F: T/F Boiler explosions would not occur if all boilers had an MAWP of 15 psi. 108.F: T/F Soot accumulation on the tubes of a watertube boiler does not affect the efficiency of the boiler. 109.F: T/F In both firetube and watertube boilers, the fire is inside the tubes. 110.F: T/F Scale protects the boiler heating surfaces. 111.F: T/F A safety valve discharge line cannot be discharged outside of the boiler room. 112.F: T/F Open and closed feedwater heaters are never used at the same time. 113.F: T/F A hydrostatic test will determine whether a steam boiler has sufficient relieving capacity. 114.F: T/F All firetube boilers are horizontal boilers. 115.F: T/F The stop valve in a boiler feedwater line should have the pump discharge pressure on the top of the valve disc when the valve is closed. 116.F: T/F The interior of the Bourdon tube in a steam pressure gauge is always filled with live steam when it is operating. 117.F: T/F Softened water is used in a boiler to prevent pitting of the boiler metal. 118.F: T/F The boiling point of water is not affected by boiler pressure. 119.F: T/F Blowing down the water column and gauge glass too frequently can cause a false water level. 120.F: T/F In the closed feedwater heater, steam and water come into direct contact with each other. 121.F: T/F Pressure on water does not change the boiling point of the water. 122.F: T/F Boiler blowdown tanks do not require vents because the water is discharged to the sewer. 123.F: T/F A boiler feedwater pump cannot become steambound. 124.fan failure: The air-proving switch attached to the housing of a fully automatic rotary cup burner opens when there is ___. 125.feedwater: An economizer heats ___. 126.feedwater: An economizer is used to preheat ___. 127.feedwater line: A stop-and-check valve is installed in the ___. 128.feedwater pressure is higher than the boiler pressure: In a closed feedwater heater, the ___. 129.firetube: A scotch marine boiler is a ___ boiler. 130.firetube: Staybolts are most commonly used in ___ b oilers. 131.firetube boilers: Staybolts are most commonly found on ___. 132.five: A slow-opening valve requires ___ complete turns to be fully opened or closed. 133.flash when exposed to an open flame: The flash point of fuel f uel oil is the minimum temperature at which the fuel oil will ___. 134.forced draft: The underfeed stoker in steam pl ants uses ___. 135.Four: ___ percent of the steam generated in a boiler is used for the steam atomizing burner. 136.full: If the steam valve to the gauge glass is closed or the top line is clogged, the gauge glass will be ___. 137.gases of combustion as they leave the boiler: An economizer is used to heat the feedwater before it enters the boiler by using ___.
138.Globe: ___ valves should be used for throttling service. 139.hairline cracks in the refractory: Spalling in a boiler refers to ___. 140.heat from the gases of combustion can be reclaimed: Economizers are used in large plants so that ___. 141.heat the fuel oil as it comes from the fuel oil tank: When using No. 6 fuel oil, the boiler operator must ___. 142.high fixed carbon: Anthracite coal has a ___ content. 143.high volatile: Bituminous coal has a ___ content. 144.horizontal return tubular: In boiler room work, HRT means ___. 145.hydraulic turbine cutters: Scale on a watertube boiler can be removed by ___. 146.impurities on the boiler water surface: Foaming may be caused by ___. 147.incomplete: Carbon monoxide in the flue gas is a sign of ___ combustion. 148.incomplete combustion: Smoke is the result of ___. 149.infrared light: A lead sulfide cell, which is used for flame detection, is sensitive to ___. 150.infrared rays: A l ead sulfide cell is sensitive to ___. 151.inside tube surface: In a firetube boiler, soot settles on the ___. 152.internal resistance to flow: The viscosity of fuel oil is the measurement of the ___ in the fuel oil. 153.leaks through the boiler side wall: Boiler CO2 readings of 12.5% over the fire, 11.5% in the second pass, and 8% at the damper indicate ___. 154.Lime; soda ash: ___ and ___ are used to soften feedwater. 155.lowest; flow: The pour point of fuel oil is the ___ temperature at which fuel oil will ___. 156.maintains a constant water level: An automatic feedwater regulator ___. 157.manometer: Draft is measured with a ___. 158.manufacturer or an authorized representative of the manufacturer: According to the ASME Code, any repairs done on a boiler safety valve must be done by the ___. 159.mixture; atomization; temperature; time: To obtain complete combustion of a fuel, ___, ___, ___, and ___ are required. 160.monthly: An evaporation test should be performed ___ to check the low water fuel cutoff control. 161.mud drum: The bottom blowdown line of a high pressure watertube boiler is connected to the ___. 162.No. 6: Steam atomizing burners can be used to burn ___ fuel oil at lower temperatures. 163.none of the above: A ¾" blowdown line may be used if the boiler has ___ sq ft f t of heating surface. (a) more than 100, (b) less than 199, (c) more than 500, or (d) none of the above 164.oily waste rags: Fires caused by spontaneous combustion would probably start in the ___. 165.on a watertube boiler: Soot blowers are most commonly found ___. 166.open feedwater heater: Condensate is returned to the boiler with the makeup water in the ___. 167.open the air cock: To prevent a vacuum from forming on a boiler that is coming off-line, ___. 168.operating pressure control: The operating range of a steam boiler is controlled by a(n) ___. 169.os&y or lever: The valves located between the boiler and the water column are ___ valves and must be locked and sealed open. 170.outside diameter: Boiler tubes are sized using the ___. 171.outside of the boiler shell: The furnace of an HRT boiler is ___. 172.Overfire air: ___ is necessary to burn the volatile matter in coal more efficiently. 173.overheating of the boiler metal: Scale deposit in an HRT boiler can cause ___.
174.pea; buckwheat; rice; barley: Beginning with the largest size, ___, ___, ___¸and ___ are the grades of anthracite coal. 175.person familiar with the construction, operation, and maintenance of a safety valve: According to the ASME Code, the setting or adjusting of a boiler safety valve must be done by the ___. 176.photocell: A ___ sensor in a flame scanner senses visible light from the burner. 177.pitting: Oxygen in the boiler causes ___. 178.positive draft pressure: The air switch, which is located on the forced draft fan housing of a rotary cup burner, ensures ___. 179.positive-displacement: 179.positive-displacemen t: A steam-driven reciprocating pump is a ___ pump. 180.pounds, square inch: A steam pressure gauge is calibrated in ___ per ___. 181.pressure: A vaporstat control is sensitive to ___. 182.pressure: A pressure control is sensitive to ___. 183.pressure or vacuum: A compound pressure gauge indicates ___. 184.prevent formation of scale: Boiler feedwater is chemically treated to ___. 185.prevents backflow from the boiler into the feedwater line: The check valve on the boiler feedwater line ___. 186.prevents corrosion at low rating: The bypass damper on an air heater ___. 187.pulling the test lever by hand and then releasing it to allow it to "snap" closed: Manual testing of the safety valve is accomplished by ___. 188.purging after ignition failure: A furnace explosion can be prevented by ___. 189.pyrometer: A(n) ___ is used to measure furnace temperature. 190.quick-opening; last: High pressure boilers equipped with quick-opening and screw-type valves are blown down by opening the ___ valve first and closing it ___. 191.radiation: Most of the heat is transferred from the fire to the boiler heating surface surrounding the fire by ___. 192.recommended feedwater treatment: To ensure good heat transfer in a firetube boiler, the outside of the tubes are kept clean b y ___. 193.recovers low pressure steam: A flash tank ___. 194.reduces the turbulence of water in the gauge glass: The water column on a high pressure steam boiler ___. 195.remove sludge and sediment: A steam boiler is blown down to ___. 196.removes moisture form the steam: A dry pipe ___. 197.removes moisture from steam: A dry pipe on a boiler ___. 198.removes sludge and sediment from the mud dr um: The bottom blowdown on a boiler ___. 199.Ringelmann: The ___ test is used to test the density of smoke l eaving a boiler. 200.rolled and beaded: Tubes in a firetube boiler are ___. 201.rotating cup and primary air: The atomization of fuel oil in a rotary cup burner is caused by the ___. 202.run of mine; lump; nut; slack: Beginning with the largest size, ___, ___, ___, and ___ are the grades of bituminous coal. 203.scale buildup inside the tubes: Overheating of tubes on a watertube boiler can be caused by ___. 204.scale; inside: Overheating of tubes in a watertube boiler is caused by ___ on the ___ of the tubes. 205.secure all of the feedwater going to the boiler: To test a low water fuel cutoff using an evaporation test, the boiler operator must ___.
206.secure the feedwater and fires to the boiler, allow the boiler to cool slowly, and notify the chief engineer: If steam comes out of the bottom try cock, the boiler operator must ___. 207.secure the fires: When the boiler l ow water alarm is ringing, the operator should ___. 208.set at 1 ½ times the MAWP: When making a hydrostatic test on a boiler, the safety valves must be ___. 209.silica gel: Boilers that are laid up dry have trays of ___ put in the steam and water drums to absorb moisture. 210.siphon: The Bourdon tube in a steam pressure gauge is protected by a ___. 211.slightly lower than line pressure: To cut a boiler in on a line equipped with hand-operated main steam stop valves, the steam pressure p ressure on the incoming boiler should be ___. 212.soot blower: Soot on the outside of boiler tubes is removed by a ___. 213.soot blowers: To ensure good heat transfer in a watertube boiler, the outside of the tubes are kept clean by ___. 214.spring-loaded: A pop-type safety valve is a ___ type. 215.steam and water flow out of the middle try cock: When checking the water level in a steam boiler with try cocks at the NOWL, ___. 216.Steam entering the huddling chamber exposing a larger area for the steam pressure to act on: ___ makes a pop-type safety valve pop open. 217.steam flow, feedwater flow, and water level: In a three-element feedwater regulating system, ___ are measured. 218.steam leaving the boiler: The boiler superheater r aises the temperature of the ___. 219.steam piston is larger than the water piston: In a reciprocating feedwater pump, the ___. 220.steam temperature: A siphon installed between the boiler and the pressure gauge protects the Bourdon tube from___. 221.Sulfur: ___ dioxide is a major cause of air pollution and is caused by burning fuel oil. 222.superheated: Saturated steam at 200 psi that passes through a reducing valve and is reduced to 20 psi becomes low pressure steam that is ___. 223.superheated steam: A boiler steam pressure of 100 psi with a temperature of 500°F indicates ___. 224.surface tension: Water polluted with foreign matter causes an increase in ___. 225.T: T/F The low water fuel cutoff control shuts off the fuel to a burner when a low water condition occurs. 226.T: T/F The largest heat loss in a boiler is caused by heat being carried with the gases of combustion to the atmosphere. 227.T: T/F The safety valve on the superheater header should be set to blow before the safety valves on the steam and water drum. 228.T: T/F Both stop and check valves must be installed on the boiler f eedwater line. 229.T: T/F Waterwalls permit greater heat absorption per cubic foot of furnace volume than refractory walls. 230.T: T/F If a plant has only one boiler, an automatic nonreturn valve is not necessary. 231.T: T/F The automatic nonreturn valve is on the main steam line. 232.T: T/F If the top line to a boiler gauge glass were closed, the water in the glass would rise to the top. 233.T: T/F According to the ASME Code, weighted lever safety valves cannot b e used on boilers. 234.T: T/F A low water fuel cutoff control should be tested by blowing down the float chamber at least once a shift. 235.T: T/F Priming can be a direct result of maintaining too high a water l evel in the boiler.
236.T: T/F To prevent water hammer, water should be drained out of all high pressure steam lines 237.T: T/F A change in water pressure will change the boiling point of water. 238.T: T/F Try cocks on a water column can be used to determine the water level if the gauge glass is broken. 239.T: T/F When air preheaters or economizers are used in a boiler, b oiler, induced draft is usually employed. 240.T: T/F The fire point of fuel oil is the minimum temperature at which fuel oil burns continuously. 241.T: T/F The flash point of fuel oil is lower than the fire point. 242.T: T/F Corrosion of the seat and disc of a safety valve can cause the valve to stick in a closed position. 243.T: T/F Steam boilers that are out of service can be laid up wet or dry. 244.T: T/F In a pop-type safety valve, the huddling chamber is constructed to assist in opening the valve. 245.T: T/F Poor grades of No. 6 fuel oil can be used quite well with a steam atomizing burner. 246.T: T/F The most common causes of boiler accidents or explosions are low water and insufficient purging of the combustion space. 247.T: T/F The dry pipe separator is in the steam and water drum. 248.T: T/F A dry pipe separator increases the quality of steam leaving a steam boiler. 249.T: T/F An increase in chimney temperature indicates soot on the heating surfaces of a boiler. 250.T: T/F The purpose of safety valves is to protect the boiler from exceeding its MAWP. 251.T: T/F The discharge outlet size of a safety valve must not be restricted or reduced. 252.T: T/F A closed b oiler room that does not permit the pr oper flow of outside air to the furnace will have combustion problems. 253.T: T/F All steam boilers must have one or more safety valves. 254.T: T/F Three methods of heat transfer are radiation, convection, and conduction. 255.T: T/F Preheaters heat air for combustion. 256.T: T/F An airtight boiler room will prohibit complete combustion. 257.T: T/F Dry saturated steam is in a gaseous state. 258.T: T/F Safety valves on superheaters should be set to open before main safety valves on boilers. 259.T: T/F An economizer is a fuel-saving device that reclaims heat from the gases of combustion. 260.T: T/F An economizer is a heat exchanger that absorbs heat from the gases of combustion leaving the boiler. 261.T: T/F Steam traps are used wherever condensate collects. 262.T: T/F A steam trap is a device that removes air and condensate without loss of steam. 263.T: T/F A false water level l evel reading can occur if the water column or gauge glass blowdown valves are not fully closed. 264.T: T/F Foaming can lead to carryover. 265.T: T/F Safety valves are located on the uppermost part of the steam and water drum and the outlet of the superheater header. 266.T: T/F If a safety valve leaks after testing, the valve should be fully opened using the test lever. If the valve continues to leak, the boiler should be removed from the line as soon as possible and the safety valve should be repaired or replaced. 267.T: T/F Try cocks are not effective above a steam pressure of 250 psi. 268.T: T/F The main function of a steam trap is to remove air and condensate without the loss of steam.
269.T: T/F Burning fuel is a chemical reaction that releases heat. 270.T: T/F One of the purposes of a bottom blowdown line is to remove impurities from the boiler. 271.T: T/F The water column reduces the turbulence of the water to give a more accurate reading in the gauge glass. 272.T: T/F An open feedwater heater vents gases to the atmosphere. 273.T: T/F Purging a furnace before f iring can prevent a furnace explosion. 274.T: T/F The main function of a continuous blowdown system is to lower the total concentration of solids in the boiler. 275.T: T/F In an open feedwater heater, the water and steam come into direct contact; in a closed feedwater heater, the water and steam are separated. 276.T: T/F The atmospheric pressure at sea level will support a column of mercury approximately 30" high. 277.T: T/F When conducting a hydrostatic test, all safety valves are either gagged or removed and blank flanged, and the pressure is increased to 1 ½ times the MAWP. 278.T: T/F When boilers are set in battery, the main steam stop valves, bottom blowdown valves, and feedwater valves should be locked l ocked closed before anyone enters the boiler drums. 279.temperature: Pyrometers measure ___. 280.temperature: A pyrometer measures ___. 281.testing the boiler water: The frequency of blowing down the boiler can best be determined by ___. 282.the amount of moisture in the steam: The throttling calorimeter determines determines ___. 283.the boiler has under 100 sq ft of heating surface: The size of bottom blowdown lines can be reduced when ___. 284.the boiler should be at least 75% of popping pressure b efore testing: When testing the safety valve by hand, ___. 285.the boiler's main steam stop valves, f eedwater lines, and bottom blowdown lines be closed, locked, and tagged out: Proper safety procedure requires that ___ before anyone is allowed to enter the steam and water drum. 286.the formation of slag: A difficulty found when burning pulverized coal is ___. 287.the proportional chemical pump: Chemicals are added to the boiler water by ___. 288.the rotary cup and primary air: In a rotary cup burner, atomization is achieved by ___. 289.the same: The purge cycle of a combination gas/fuel oil boiler is ___ when burning fuel oil as when burning gas. 290.the steam piston must be 2 to 2 ½ times larger in area that the water piston: A duplex reciprocating feedwater pump operates on the principle that ___. 291.the superheater safety valve opens first: The safety valves on the boiler drum and superheater safety valves of a steam boiler are set so that ___. 292.the top line is closed or clogged: A slowly rising water level in the gauge glass indicates that ___. 293.thoroughly clean the fire and water sides: Before laying up a boiler, the boiler operator must ___. 294.tin: A boiler fusible plug is brass or bronze with a core of ___. 295.try cock: The ___ is a secondary means of determining boiler water level. 296.two: According to the ASME Code, if a boiler has a MAWP that exceeds 100 psi, the boiler must have ___ blowdown valve(s). 297.using try cocks: While replacing a broken gauge glass with the boiler under pressure, the water level is checked by ___.
298.weight of moisture, fixed carbon, volatile matter, and ash: A proximate analysis of coal is used to determine the ___. 299.when the firebox is cool but the boiler still has pressure: Boiler waterwalls should be blown down ___. 300.wire brush and vacuum cleaner: Soot on the inside of boiler tubes is removed by a ___.
