Heat Engines, Prime Movers & Steam Turbines PDF

Chapter 69 Heat Engines, Prime Movers & The Simple Steam Engine Answer B A prime mover is a) an electric motor b) a steam turbine c) a centrifugal pump d) an air compressor e) a boiler Answer C Large power production plants tend to be of the thermal type because they can burn solid fuels and: a) they are the least expensive to build b) the noise level is much less than internal combustion engines c) the heat cycle they use is the most efficient d) solid fuels are the most plentiful and cheapest e) require the least amount of manpower Answer C Whenever feasibly possible, when checking bearings on running pieces of equipment it is wise to a) check the oil quality leaving each b) check the oil quantity leaving each c) get accustomed to normal running temperature and vibration by feel d) smell the normal odors of the running bearing e) observe the temperature on a thermometer Answer A One of the first ways to detect a fault in a reciprocating engine is a) by sound b) temperature indication c) performance efficiency d) by oil consumption e) by smell Chapter 70 Steam Turbines I Answer D A steam turbine's exhaust can often supply a process with steam because a) processes always require a lower steam pressure b) processes never require the high steam temperatures turbines do c) turbine exhaust steam is always dry and saturated d) it is free of oil e) the steam will be at a temperature above the initial temperature Answer C The exhaust steam from a steam turbine is more acceptable for process than the exhaust from a steam engine because a) it is much hotter b) it is easily controlled c) it is free of oil d) it is free of moisture e) it contains more condensate Answer D Turbines often have segmental carbon ring sealing glands which are held in place by a) labyrinths b) shrouding c) drive screws d) garter springs e) thrust runners Answer D A steam turbine should trip or shut down when normal operating speed is exceeded by a) 250 RPM b) 3 to 5% c) 50 RPM d) 10 to 15% e) 25 RPM Answer B Condensing turbines a) are always impulse turbines b) will have a vacuum in the last row of rotating blades c) will use the condensate for heating d) are very small units e) cannot have counterflow stages Answer B Which turbine uses a condenser? a) back pressure turbine b) a turbine exhausting to a vacuum c) a bleeder turbine exhausting at atmospheric pressure d) a non-condensing extraction turbine e) a turbine exhausting to atmosphere Answer E The shrouding installed on the blading of a steam turbine serves to: a) cool the blade tips b) expand the steam c) stop the steam flow d) heat the steam e) confine the steam to the blades Answer A The turbine overspeed trip: 1. prevents the turbine from vibrating 2. prevents the turbine exceeding the maximum rated speed 3. is operated by a spring loaded pin in the rotating blades 4. will close the steam stop valve 5. should be tested before the turbine is placed in service a) 2, 4, 5 b) 2, 3, 4, 5 c) 1, 2, 4 d) 3, 4, 5 e) 4, 5 Answer B The overspeed trip of a steam turbine a) operates on turbine vibrations due to high speed b) is installed on all turbines c) can be adjusted according to the load demand d) is regulated by exhaust pressure e) sheds the load in the event of high pressure Answer B Turbine overspeed trip a) prevents the turbine from vibrating b) will close the steam stop valve to the turbine c) is operated by a spring loaded pin in the rotating blades d) supplies the operator with rpm indications e) reduces the turbine speed by increasing the back pressure Answer D Turbine lubricating oil a) is not required for small impulse turbines b) must be changed every four months c) lubricates the blades d) can be used to operate the turbine governor e) should be preheated before use Answer C The purpose of turbine glands is to prevent a) water from entering the turbine b) steam from entering the turbine c) steam escaping from the turbine d) steam from entering the lubrication system e) oil from entering the turbine Answer E Shaft sealing in high output turbines is done with a) water seals b) mechanical seals c) wear rings d) packing glands e) labyrinth seals Answer B When the steam pressure drop occurs in only the stationary members or components of a turbine, the turbine is known as a) a single stage unit b) an impulse unit c) a reaction unit d) a Parsons unit e) a cross compound reaction unit Answer E A large reaction turbine will have a) no thrust bearings b) steam pressure dropping in only the moving sections c) blades which are basically symmetrical in cross-section d) never more than 5 stages e) steam pressure dropping through moving and stationary sections Answer D Turbine speed can be "fine tuned" with a device which will be limited to about 10% over the rated speed. This device is the a) governor valve b) overspeed governor c) sentinel valve d) hand speed control e) overspeed trip Answer C Turbine thrust bearings are fixed to the casing and prevent axial movement of the spindle by contacting a component on the shaft known as a a) shaft sleeve b) labyrinth c) collar d) shroud e) diaphragm Answer D Shaft sealing carbon glands are a) lubricated by the main oil pump b) limited to a temperature of 250 degrees C c) replaced monthly due to erosion d) self-lubricating e) metal sprayed components Answer C The great majority of steam turbine governing systems utilize the a) hydraulic system principle b) pneumatic system principle c) mechanical centrifugal principle d) lever principle e) bimetal expansion principle Answer B Reaction turbines a) have bucket shaped blades b) have a pressure drop through the moving and stationary blades c) are used for high pressures only d) have a pressure drop in the moving blades only e) have little axial thrust Answer B Reaction turbines a) have all of the steam pressure drop take place in the stationary nozzle b) have a velocity increase in the fixed blading c) are used for higher speed only d) have a velocity decrease through the fixed blading e) require little blade sealing Answer B In an impulse turbine a) the steam flow is reduced through the nozzles b) the steam pressure is reduced in the nozzles c) the steam pressure will drop across the blades d) the steam velocity is increased through the blades e) the exhaust steam is directed back to the boiler Answer E The steam turbine that has a pressure drop across every set of blades is the __________ turbine. a) double-stage impulse b) single-stage impulse c) topping d) back pressure e) reaction Answer D When starting a steam turbine it is customary practice to a) analyze the oil for water prior to rolling b) turn on all cooling water systems first c) place the speed control system in service once the unit is rolling d) test the overspeed trip as soon as running speed is attained e) stop the auxiliary oil pump as soon as steam begins to turn the unit Chapter 71 Cooling Towers Answer D The average amount of water volume which evaporates from a cooling tower is a) 2% b) 10% c) 15% d) 5% e) 3.5% Answer A Natural draft cooling towers operate most effectively in large open spaces and a) where wind is relatively constant b) where relative humidity is high c) where a large body of water is nearby d) require a windbreak e) must not be in direct sunlight Answer B Excessive wind velocity in a natural draft cooling tower may cause a) louvers to become broken b) high water drift or losses c) rotation reversal of the fan d) over-cooling of the water e) under-cooling of the water Answer C Compared to a crossflow tower, a counterflow tower a) is not as tall b) has much less capacity c) requires less floor space d) requires more fan power e) has a higher pressure drop Answer E Water contained in the airstream at the discharge of a cooling tower is removed a) with centrifugal separators b) by a series of chevron dryers c) by refrigeration means d) by a series of baffles e) with drift eliminators Answer C A cooling tower which requires neither fan nor fill is the a) natural draft unit b) counterflow induced unit c) venturi unit d) crossflow unit e) forced draft unit Answer E A valve which prevents water flow over the fill of a tower during cold weather should not be closed until the temperature reaches a) - 0.5 degrees C b) + 0.5 degrees C c) + 5 degrees C d) + 20 degrees C e) + 27 degrees C Answer B To prevent cooling tower basin water from freezing during cold weather many units are equipped with a) ethylene glycol antifreeze systems b) electric basin heaters c) propane burners d) ice defrosters e) warming tapes Answer D You are replacing the cooling tower fan motor bearings because a) the motor was running single phase b) windings in the motor were faulty c) a noise which sounded like a bad bearing was heard d) the rotor was rubbing the stator e) the gear reducer pinion shaft was misaligned Answer D Scaling is not as severe in towers when compared to boilers because a) tower water does not evaporate b) there are not as many dissolved solids in tower water c) pressure is not as high d) temperatures are not as high e) water is constantly being aerated Chapter 72 Gas Turbines I Answer C A gas turbine compressor is usually a) centrifugal type b) downstream of the turbine c) dynamic axial design d) downstream of the combustor e) driven by a motor Answer A The compressor on the gas turbine a) can be driven by the load turbine b) is always of the axial type c) is always a multi-stage compressor d) is always independently driven e) is always a reciprocating type Answer C The combustion chamber of a gas turbine a) increases the pressure of the compressed air b) is heated between the load turbine and the compression turbine c) burns fuel with excess air d) is water cooled e) rotates at shaft speed Answer D Many typical steam plant auxiliaries are eliminated with a gas turbine due to its a) small size b) high speed c) high power to weight ratio d) simplicity e) low oil consumption Answer B Gas turbines are very popular where a) noise does not present a problem b) water is scarce c) industrial sites are small and in congested areas d) thermal pollution is of major concern e) natural gas is plentiful Answer B Gas turbines are ideal when considering a) long warm-up periods b) emergency power generation c) automotive power d) cooling water pump operation e) good thermal efficiency Answer A A two shaft gas turbine a) has the load turbine downstream from the compressor turbine b) has the first turbine drive the prop on a turbo-prop engine c) is always an open cycle type d) is always a closed cycle type e) does not require a starting motor Answer C A gas turbine is not self-starting. It must be rotated at __________ of its maximum speed before fuel is turned on. a) 10% to 30% b) 15% to 30% c) 20% to 30% d) 25% to 30% e) 25% to 50% Answer C Early gas turbines were handicapped by a) metal not being able to withstand high speed centrifugal forces b) the inability to get enough air into the combustion chamber c) metals not standing the high temperatures involved d) their high operating speeds e) their inadequate power capability Answer D The temperature to which the air can be raised at the turbine inlet is a) an indication of a unit's power b) directly related to the unit's size c) a function of the air compressor input d) an indication of the unit's efficiency e) important for proper compressor performance Answer A The output power of a gas turbine is directly related to the a) mass of gas passing through the turbine per second b) temperature at the turbine inlet c) mass of the unit d) slippage between the turbine and compressor e) turbine exhaust temperature Answer E The low installation cost of a gas turbine is a) due to cheap materials in the blades b) due to short fuel lines c) because no fuel pump is required d) because no electrical wiring is required e) because less auxiliary equipment is needed Answer C Some of the characteristics which make the gas turbine a better choice over other prime movers are: 1. low maintenance 2. minimum cooling water 3. high thermal efficiency 4. rapid start-up and loading a) 1, 2, 3, 4 b) 1, 2, 3 c) 1, 2, 4 d) 1, 3, 4 e) 2, 3, 4 Answer E The air side of a gas turbine regenerator is located a) before the compressor b) after the combustion chamber c) between the turbine and combustion chamber d) between the turbine and atmosphere e) downstream of the compressor Answer D A gas turbine performs most effectively if a) lube oil is of the proper viscosity b) cooling water temperature is kept low c) ambient air temperature is high d) ambient air temperature is low e) loaded immediately after starting Answer B A combined steam and gas turbine arrangement can be termed a) an ideal system b) a cogeneration system c) a once through system d) ideal relative to system efficiency e) a high capacity system Answer B The purpose of a regenerator is a) to clean the exhaust gases b) to improve the efficiency of the turbine c) to increase the temperature in the combustion chamber d) to lower the temperature in the combustion chamber e) to recirculate the exhaust gases back through the compressor Chapter 73 Internal Combustion Engines I Answer B In a compression ignition engine the fuel is ignited by a) an electric spark b) the compressed air temperature c) the atomized fuel d) a cross-combustor e) compressed air pressure Answer C Diesel engine governing is accomplished by a) varying the fuel quality b) carburetion c) varying the fuel quantity d) fuel atomizing air quantity e) fuel atomizing air pressure Answer C The fuel for a diesel engine is a) light fuel oil b) vaporised by a carburettor c) mechanically atomized by high pressure d) atomized before the cylinder e) mixed with air before the cylinder Answer A Four-stroke cycle engine valves are a) operated by cams b) of the pressure differential variety c) a number of ports in the cylinder wall d) often termed reed or channel valves e) always open as the piston travels upwards Answer C An engine which develops one power stroke with every other turn of the crankshaft is the a) two stroke diesel engine b) type which requires pre-mixing lube oil and fuel c) four stroke natural gas engine d) V type engine e) external combustion unit Answer A Four cycle engine lubrication is usually a) forced by pump b) by gravity oilers c) by the scoop method d) by the dip tube method e) by grease fitting Answer C An example of an engine which gives high torque at low speeds would be that of a a) chain saw b) two cycle snowmobile c) four stroke motocross motorcycle d) two cycle lawnmower e) two cycle transit bus Answer D A two cycle engine a) must always have lube oil premixed with the fuel b) can never have a crankcase lubrication system c) can never be operated in an inverted position d) "pops" twice as often as an equivalent cylinder four stroke engine e) gives one power stroke every other crankshaft revolution Answer A Pre-mixing lube oil and fuel or having a special lube oil injection system is typical of the average a) snowmobile engine b) automobile engine c) aircraft engine d) tractor engine e) heavy equipment engine Answer E A major difficulty encountered with a two-stroke cycle engine is a) the high torque at low speeds b) maintenance of many moving parts c) the difficulty in cold weather starting d) the high speeds compared to an equivalent four stroke engine e) exhausting the spent gases from the cylinder Answer E A two cycle gasoline engine a) has more moving parts than a four cycle b) produces twice as much power as a four cycle c) must have two cylinders d) does not require exhaust valves e) is of more simple construction than a four cycle Answer C Cylinder scavenging a) is more efficient in a 2 cycle engine than a 4 cycle type b) is scoring the cylinder by a broken piston ring c) is the removal of exhaust gases from the cylinder d) prevents the air from entering the cylinder e) removes excessive oil from the cylinder walls Answer A The purpose of a spark plug is a) to ignite the fuel air mixture in a gasoline engine b) to produce power for the compression stroke c) to prewarm the engine d) to raise the ignition point of the fuel e) to ignite the air in the cylinder Answer B Compression ignition engines a) need suction end discharge valves b) will compress air only on the compression stroke c) need a carburettor to mix the fuel with the air d) will compress air only on the power stroke e) require a spark timing device Answer E The injection pump of a diesel engine is driven by a) piston action b) the governor c) the wrist pin d) the gudgeon pin e) the camshaft Answer D Ignition in a diesel engine is started by a) a glow plug b) a spark plug c) a starter motor d) compression in the cylinder e) air injection Answer A Using a compressed air starting motor is a popular method of starting a a) large stationary diesel engine b) small two stroke engine c) jet engine d) high performance engine e) natural gas engine Answer D When using compressed air to each cylinder for starting purposes, the pressure is approximately a) 520 kPa b) 255 kPa c) 3,030 kPa d) 2,100 kPa e) 435 kPa Answer C Reduction in sealing qualities between the piston rings and cylinder wall by the lube oil may be the result of a) low cooling water temperature b) high lube oil viscosity c) high cooling water temperature d) high carbon residue of the lube oil e) wrong fuel being used Chapter 74 Types of Pumps Answer E A pump is capable of suction lift due to a) its ability to convert kinetic energy into potential energy b) the speed at which it operates c) its input power d) its size e) atmospheric pressure Answer C Centrifugal pumps do not develop good suction lift because a) atmospheric pressure is usually too low b) the pumped medium relative density is too high c) their internal component clearances are too high d) the speed is too low e) they favour pressure rather than volume Answer A It is generally accurate to say that a) 9.8 kPa pressure results from every metre of water depth or height b) a water height or depth of 10.34 metres results in 1 kPa c) 1 kPa will result from a water head of 9.8 metres d) 10.21 kPa will result from 1 metre of static water head e) atmospheric pressure has no bearing on static water head Answer E Preferably, dynamic pumps should be located a) directly under the liquid source when suction lift is involved b) above the liquid source when suction head is involved c) above the liquid source when suction lift is involved d) at the liquid source level when suction lift is involved e) below the liquid source when suction head is involved Answer E The vertical distance from the liquid surface up to the pump centre-line plus the vertical distance from the pump centre-line up to the surface of the liquid in the discharge tank is a) static discharge head b) static suction head c) suction lift d) total discharge head e) total static head Answer A The difference between static suction head and static discharge head is a) total static head b) static discharge head c) static suction head d) equivalent head e) dynamic head Answer B When a pump discharges into a vessel operating at 300 kPa, the 300 kPa is referred to as a) dynamic head b) equivalent head c) discharge head d) friction head e) total head Answer B The total static head of a pump a) is the capacity of the pump b) is the difference between the static suction head and the static discharge head c) is the discharge pressure in metres d) is all the parts of the pump casing e) is the discharge head of the pump Answer B When a reciprocating pump discharges while its piston or plunger moves in only one direction, it is termed a a) positive displacement unit b) single acting unit c) dynamic unit d) double acting unit e) duplex unit Answer D Centrifugal pumps convert rotating mechanical energy into kinetic energy then a) discharge the kinetic energy b) back to mechanical energy c) absorb the energy d) into potential energy in the form of pressure e) into centrifugal force Answer C A hot water heating system circulator should a) be directly coupled b) have its own vibration-free base c) be very quiet in operation d) develop an extremely high differential pressure e) not run continuously Answer A The capacity of a centrifugal pump a) varies with discharge pressure b) can be altered by speed variation only c) indicates that the unit is a positive displacement type d) should be varied by suction valve manipulation e) is fixed and can only be altered by changing the impeller Answer B Centrifugal pump power requirements are decreased when a) discharge pressure is decreased b) the litres moved per minute is decreased c) the casing pressure drops d) the discharge velocity is high e) the discharge head is at minimum Answer C A rotary pump a) is a variety of dynamic unit b) never has discharge pulsations c) should be equipped with a relief valve d) has the highest capacity of any pump e) never requires cylinder lubrication Answer B When starting-up a rotary pump you must be sure that the a) discharge valve is closed b) discharge valve is open c) pump is filled with air d) pump is at the correct temperature e) pump suction valve is closed Answer C Rotary pumps: 1. are high pressure pumps 2. must be primed 3. use mechanical seals 4. are positive displacement pumps a) 1, 2 b) 2, 3 c) 1, 4 d) 1, 3, 4 e) 1, 2, 3, 4 Answer E A double-acting pump a) has two pistons on the pump end b) will always be driven by the steam pistons c) has two pistons on the driver end d) will have two slide valves e) is a positive displacement pump Answer B A volute type pump a) is a positive displacement pump b) has a progressively expanding spiral casing c) reduces the velocity in the discharge nozzle d) is more costly than diffuser pumps e) is a regenerative type pump Answer D A diffuser pump: 1. has stationary guide vanes surrounding the impeller 2. has a higher efficiency than a volute type 3. has high suction lift 4. does not have to be primed a) 1 b) 3 c) 2, 3 d) 1, 2 e) 4 Answer C Turbine pumps: 1. are high capacity pumps 2. are high pressure pumps 3. has the liquid gain energy in a number of impulses a) 1 b) 1, 2 c) 2, 3 d) 1, 2, 3 e) 1, 3 Answer A A centrifugal pump consists of a) an impeller surrounded by a casing b) a piston moving to and fro in a cylinder c) gears rotating in a housing d) sliding vanes e) pulsating disc Answer E The capacity of a centrifugal pump should only be reduced by a) throttling the suction valve b) closing in the suction valve c) closing in both the suction and discharge valves d) opening the pump casing vent valve e) closing in the discharge valve Answer B Cavitation of a pump refers to, when: a) the pump is filled with air b) the pump is filled with vapour c) the oil ring is damaged d) the suction valve is open e) the pump is steam driven Answer D Rotary pumps: 1. have tight clearances on all moving parts 2. deliver high pressure liquid without pulsations 3. are positive displacement units 4. should not be started with discharge closed a) 1 b) 1, 2 c) 1, 2, 3 d) 1, 3, 4 e) 2, 3 Answer E If a pump is cavitating what can you do to prevent or reduce the cavitation? a) close the casing vent valve b) open the vent valve and close the suction valve c) partially close the suction valve d) close the discharge valve e) raise the suction pressure Answer D A positive displacement stand by-pump will have a) the vent and drain valves open b) the suction valve closed and the discharge valve open c) the suction valve open and the discharge closed d) the suction valve open and the discharge valve open e) the suction valve and the discharge valves closed Answer B Pumps handling cryogenic materials operate a) as staged units b) at extremely low temperatures c) nearly always as dynamic units d) as tandem units e) as high speed units Answer A A circulating pump is usually a) connected with some type of heat exchanger system b) a once through device c) mounted to the piping d) a small capacity unit e) a high head unit Answer C A multi-stage pump would be used a) when the lift is great b) when a greater volume must be pumped c) when the head is great d) when the temperature of the water being pumped is high e) whenever there is sufficient boiler room floor space Answer B Turbine pumps are best suited for a) low capacity low pressure service b) low capacity high pressure service c) high capacity high pressure service d) high capacity low pressure service e) heavy viscous fluids Chapter 75 Pump Operation and Maintenance Answer A Pump wear rings are installed on an impeller by set screws, threading or a) shrinking b) welding c) brazing d) soldering e) forging Answer C Wear rings are usually constructed of a) ceramics or aluminum b) graphite or bronze c) bronze or cast iron d) steel or alloy steel e) wrought iron or pig iron Answer B Wearing rings: 1. are used on impellers 2. are used on the casing 3. give protection to the shaft 4. reduce the maintenance cost of the pump a) 1, 2, 3 b) 1, 2, 4 c) 2, 3, 4 d) 2, 3 e) 3, 4 Answer E A stuffing box: 1. stops air leaking into the casing when the pressure is below atmospheric 2. decreases leakage out of the casing when the pressure is above atmospheric 3. is always supplied with a lantern ring 4. is filled with packing a) 1, 3 b) 1, 4 c) 2, 3 d) 2, 3, 4 e) 1, 2, 4 Answer B Mechanical seals: 1. are used where leakage is objectionable 2. replace stuffing boxes 3. provide a better seal than packing 4. are less costly than stuffing boxes a) 1, 2 b) 1, 2, 3 c) 2, 3 d) 2, 3, 4 e) 2, 4 Answer D Compression type packing: 1. prevents air from entering the pump 2. reduces the maintenance cost on pumps 3. protects the shaft from scoring and corrosion 4. is used with all mechanical seals a) 1 b) 2, 3 c) 2, 3, 4 d) 1, 2 e) 1, 3 Answer C Lantern rings: 1. prevent liquid leakage from the pump 2. are fed by a liquid 3. provide a seal to prevent air from entering the pump 4. are mostly used on high lift pumps a) 1, 2, 3 b) 2, 3 c) 2, 3, 4 d) 3, 4 e) 1, 2 Answer C The seal cage on the shaft of a centrifugal pump a) holds the shaft packing against the shoulder of the stuffing box b) assists in reducing shaft vibration c) distributes sealing water to the packing d) prevents water from leaking out of the pump casing e) reduces suction pressure drop Answer B The main advantage of a pump using a mechanical seal is a) lower first cost b) less maintenance c) less lubrication d) smaller shaft required e) increases discharge pressure Answer D A slight leakage is desired between the pump shaft and packing of the majority of pumps in order to a) prevent the ingress of atmospheric air b) increase the pump capacity and efficiency c) prevent wearing of the wear rings d) lubricate the surfaces e) prevent the pump from vapour locking Answer B If a stuffing box is to prevent the ingress of air, it is equipped with a) a vacuum breaker b) a seal cage c) a bushing d) a thrust collar e) an anti-air siphon Answer E Any leakage occurring through the surfaces of a mechanical seal will a) not be visible to the operator b) result in an audible sound and be readily noticed c) be indicated by pump vibrations d) be axial to the shaft e) be radial to the shaft Answer D The component of a mechanical seal which prevents axial leakage is a) the seal ring b) packing c) the mating ring d) the O-ring e) a diaphragm Answer E What size of packing should you use, to repack a pump gland having the following dimensions: stuffing box bore ------------- 8.6 cm pump shaft diameter ------------- 6.7 cm a).5 cm b) 1.9 cm c).675 cm d) 1.6 cm e).95 cm Answer B New pump packing should be installed a) tight enough to stop leakage b) loose enough to allow leakage for lubrication c) every shut down d) every year e) every time prior to start-up Answer B Flexible couplings will compensate for a) overheating of packing b) axial shaft misalignment c) bearing failure d) shaft eccentricity due to a badly bent shaft e) impeller imbalance Answer A Shaft misalignment during operation of a pump can be caused by bearing wear, thermal expansion, and a) shaft flexing b) throttling of the discharge valve c) overloading the pump d) loss of lubricant e) improper installation Answer D Proper priming and venting of a pump is important, especially if a) the medium being pumped is high temperature b) the medium being pumped contains suspended solids c) the pump has a stuffing box and lantern ring d) a mechanical seal is used e) oil or other low flash point lubricant is being pumped Answer B Priming of a centrifugal pump refers to a) removal of water from pump b) filling the pump casing with liquid and removing the air c) lifting the pump d) closing the vent on the pump casing e) starting the pump driver Answer D Priming a water pump means a) raising the suction line to the level of the water b) removing the foot valve to allow the water to flow through c) closing the discharge valve before starting the motor d) filling the pumps casing and suction line with water e) the water is foaming in the pump Answer B If the packing gland of a centrifugal water pump is leaking too much, you should a) tighten up the gland until all leakage has been stopped b) tighten up the gland but permit a slight amount of leakage c) tighten up the gland as far as is possible d) throttle the suction valve a little e) tighten up the gland until there is 10% leakage Answer E When lubricating equipment, the operator should also check for: 1. unusual machine noises 2. unusual consumption of lubricant 3. excessive heat in bearing housing 4. excessive leakage of lubricant a) 1, 2, 3 b) 1, 2, 4 c) 2, 3, 4 d) 1, 3, 4 e) 1, 2, 3, 4 Answer C Most pump failures, damage, or both occurs a) after about six months of continuous service b) due to vapour-binding c) during initial start-up d) due to wrong rotation e) because of inadequate operator training Answer C When a pump is operating, your inspection should include the following: a) you must check the impeller b) you must be sure the suction valve is closed c) you should check the discharge pressure d) you must be sure the drain valve is open e) you should check the oil pressure Answer E A plugged impeller symptom or result will be a) air leaks in suction line and stuffing boxes b) wrong direction of rotation c) loss of prime d) an overheated stuffing box e) no liquid being delivered Answer A If pump speed is too high a) the driver may be overloaded b) discharge pressure will be below normal c) no liquid will be delivered d) the pump will lose its prime after starting e) there will be air or gas in the liquid Answer D If a pump is running and has no discharge pressure, what will you do? a) close the suction valve a little b) open the lubrication valve c) check the lubricant level d) check to see if the suction valve is open e) close the discharge valve Answer A You discover that your feed water pump is not delivering sufficient water. A possible cause is a) the impeller is plugged b) the suction lift is too low c) the discharge head is not high enough d) there is too much water in the pump e) the foot valve is fully open Air Compression Answer A Compressed air machinery would most likely be used in a) coal mines b) residential garages c) home furnace control systems d) agricultural applications e) tool and die shops Answer D Compressed air tools tend to be a) heavier than equivalent electrical tools b) damaged by overloading c) hot after prolonged operation d) more expensive than electrical tools e) less compact than electrical tools Answer A In a centrifugal compressor the kinetic energy is converted to potential energy in the a) volute, diffuser, or both b) intercooler c) diffuser only d) compressor cavity e) volute only Answer D The compressor which would favour volume over pressure would be the a) rotary lobe b) screw c) axial d) centrifugal e) sliding vane Answer B Positive displacement air compressor types are a) centrifugal compressors b) gear compressors c) axial compressors d) multi-stage centrifugal compressors e) not capable of producing high discharge pressures Answer D Single stage reciprocating air compressors a) must have an air receiver b) could be of the rotary type c) do need an intercooler d) could have two cylinders e) have a smooth discharge delivery Answer E A belt driven lubricator is very popular on a a) reciprocating double acting unit b) screw unit c) rotary lobe unit d) centrifugal unit e) sliding vane unit Answer B Higher gearing is commonly used on a) rotary lobe units b) screw units c) sliding vane units d) reciprocating units e) centrifugal units Answer A Relative to a dry-pipe fire system, an automatic air supply shall be connected so that proper pressure can be maintained in each system, is a statement of the a) National Fire Protection Association Code b) Industrial Accident Prevention Association c) Canadian Standards Association d) Occupational Health and Safety e) Society of Municipal Fire Marshalls Answer D In order to protect the driver, a start-stop air compressor should be equipped with a) an intercooler b) an automatic blowdown system c) safety heads d) pre-start automatic unloading e) manual cylinder bleed petcocks Answer A The valves on a reciprocating compressor are opened by a) a pressure difference b) the cam shaft c) the eccentric d) hydraulic pressure e) a timing gear Answer C Compressor unloaders a) could close the discharge valve b) must be used on centrifugal compressors c) could keep the suction valve open d) activate the stop and start button e) are located on the driver of the compressor Answer B Where pistons move in a cylinder it is necessary for the lubricant to provide a) tension b) sealing c) alignment d) shock reduction e) vapour venting Answer C An air compressor which gives two compression strokes per crankshaft revolution is a) multistaged two cylinder b) multicylinder single acting c) single cylinder double acting d) a compound unit e) single acting Answer A To reduce air temperature between stages, we would use a) an intercooler b) an aftercooler c) a receiver d) a converter e) a chiller Answer B An air receiver used in an air compression, system will perform the following functions: 1. act as a storage vessel 2. eliminates pulsation in discharge lines 3. will separate out water from the air 4. controls the temperature of the air before it enters the system a) 1, 2 b) 1, 2, 3 c) 1, 2, 4 d) 2, 3, 4 e) 3, 4 Answer C An air compressor auxiliary which will decrease the power requirement is the a) receiver b) diffuser c) intercooler d) variable compression ratio head e) aftercooler Answer B Intercoolers should be equipped with a) moisture separators b) safety valves c) baffles d) vents e) automatic blowdowns Answer C Intercoolers a) cool the air in the cylinders b) are used on all compressors c) should have a safety valve d) are required to cool compressor lubricating oil e) cool the air at the inlet valves Answer A Intercoolers a) must have a drain b) are more efficient when cooled with air than with water c) are used on double acting single stage compressors d) help increase the volume of the air e) should use an antifreeze solution Answer D Air receivers a) must have a gage glass b) must have a thermometer c) must have a high pressure alarm d) must have a safety valve e) must have a high water alarm Chapter 77 Lubrication Principles Answer A Relative to lubrication, one place where wear is beneficial is a) new babbit bearing surfaces which wear smooth b) on pump wear rings c) on the oil pump sealing surfaces d) on the cylinder walls of internal combustion engines e) in antifriction bearings Answer D The intermeshing of gear teeth is a place where lubrication a) corrosion reduction is very important b) friction reduction is very important c) sealing is very important d) shock absorption is very important e) temperature control is very important Answer D The lubricant performs a number of functions. Indicate which of the following are the most important: 1. reduce wear 2. temperature control 3. reduce corrosion 4. reduce friction a) 1, 2 b) 2, 3 c) 1, 3 d) 1, 4 e) 3, 4 Answer D A material which is commonly used as a solid lubricant is a) tallow b) molybdate sulphide c) lime d) molybdenum disulphide e) sodium carbonate Answer E Grease is not a suitable lubricant a) if the atmosphere contains a lot of moisture b) when the atmosphere is dusty c) if corrosion protection is desired during downtime d) in the food industry e) if a large amount of cooling is desired Answer C A semi-solid lubricant: a) can only be used for high temperature services b) has a low viscosity c) is less likely to drip or splash from bearings d) has a low pour point e) is best suited for heat removal Answer E Lubricant for an anti-friction bearing is a) mineral oil b) graphite c) calcium or lime base grease d) not required e) barium and lithium base grease Answer D Which type of grease is the cheapest and most commonly used? a) lithium base b) teflon base c) paraffin base d) calcium base e) silicon base Answer A The property of an oil which indicates its ability to support a load is a) viscosity b) viscosity index c) pour point d) floc point e) consistency Answer A If an oil's viscosity changes much with little temperature change then it will have a a) low viscosity index b) high pour point c) high carbon residue d) high viscosity index e) low pour point Answer D Which of the following has the greatest effect on the viscosity of a lubrication oil? a) pressure b) load c) flow d) temperature e) speed Answer D The resistance of a liquid to internal deformation or shear is known as: a) pour point b) viscosity index c) flash point d) viscosity e) friction resistance Answer A Which type of oil produces higher fluid friction? a) a high viscosity oil b) a low viscosity oil c) a low viscosity oil with a high flash point d) synthetic oils e) all mineral oils Answer A Oil additives a) should not affect all other characteristics greatly b) will always affect the pour point greatly c) should be used as little as possible d) are not a component of most lube oils e) never lose their effect during use of the oil Answer B If you desire an oil to flow at a much lower temperature you would most likely add a) a viscosity index improver b) pour point depressants c) a dispersant d) a thickening agent e) low viscosity oil Answer C High capacity steam turbine oils should a) have a low specific heat b) have a very high viscosity c) be fire resistant d) have a low pour point e) mix well with water Answer B Air compressor oil should a) have a very low viscosity b) have low carbon residue c) have a low flash point d) not contain anti-oxidants e) have high shock absorption characteristics Answer A High viscosity oils are normally used for the following applications: a) low speed, high load b) low speed, low pressure c) high speed, high load d) high speed, low temperature e) high temperature, low load Chapter 78 Types of Bearing Lubrication Answer C A lubricant characteristic which will indicate its ability to support a heavy load at low speed is a) viscosity index b) pour point c) viscosity d) density e) relative density Answer E A form of lubrication which requires continual motion of a shaft or surface is a) boundary lubrication b) alemite fitting lubrication c) forced lubrication d) zerk fitting lubrication e) fluid film lubrication Answer A Fluid film lubrication a) is used for heavy loads b) removes all friction in the bearing c) is used on all anti-friction bearings d) is used only during low ambient temperature conditions e) is used for light loads Answer B Fluid film lubrication a) is always used with a high viscosity oil b) is also called flood lubrication c) is always used with a grease lubricant d) is different from flood lubrication e) does not separate the metal surfaces Answer E In a forced lubrication system, a pump supplies oil _________________ for the bearings. a) by gravity b) to an oil sump c) to a drip feeder d) to a wetted wick e) under pressure Answer D Large journal or sleeve bearings have grooves a) in the high pressure area of the bearing babbit b) cut into the bearing housing c) for distributing lubricant evenly just after the pressure area d) in the non-pressure area e) cut in them for cooling purposes Answer B A large journal bearing which is running hotter than normal can be cooled by a) direct application of cool water b) loosening the bearing caps c) decreasing the viscosity of the oil by cooling it d) adding pour point depressant to the oil e) using CO vapour 2 Answer B A thrust bearing which does not utilize the oil wedge principle of lubrication is the a) Michell type b) collar type c) flotation type d) Kingsbury type e) vertical type Answer B One of the main functions of the lubricant in a sealed, grease type antifriction bearing is a) wear reduction b) sealing c) shock absorption d) cooling e) surface separation Answer E A journal bearing a) controls thrust movement b) does not require lubrication c) improves suction pressure d) does not require a housing e) supports a shaft Answer A Thrust bearings: 1. are used on reaction turbines 2. prevent the turbine rotor moving axially 3. are always installed on both ends of the rotor shaft 4. are lubricated with the same oil as the main bearings a) 1, 2, 4 b) 2, 3, 4 c) 1, 2, 3 d) 1, 3, 4 e) 1, 2, 3, 4 Answer C The lubricant for an anti-friction bearing a) will separate the moving parts completely b) must be cooled c) could be a semi-solid lubricant d) prevents axial trust e) should have a high viscosity Answer B A collar thrust bearing: 1. can support more load than a Michell thrust bearing 2. can prevent a rotating shaft from moving in both axial directions 3. has boundary lubrication 4. is an anti-friction type bearing a) 1, 2 b) 2, 3 c) 1, 2, 4 d) 1, 2, 3, 4 e) 3, 4 Answer B A thrust bearing a) prevents radial movement of the shaft b) prevents axial movement of the shaft c) must be installed on both ends of the shaft d) has a volute casing e) should rotate opposite to the shaft Answer A An anti-friction bearing a) could be a thrust bearing b) is a bearing containing white-metal alloy c) is a sleeve bearing d) receives larger amounts of oil e) cannot operate in an oil bath Answer E A collar thrust bearing a) must have a shiny surface b) can support more load than a michell thrust bearing c) is an anti-friction type bearing d) is used with steam turbines only e) has boundary lubrication Answer C A type of anti-friction bearing is the __________ bearing. a) spiral b) elliptical c) ball d) sleeve e) journal Answer C Using pressurized air to blow out a cleaned bearing a) should only be done when ventilation is maximum b) must be done only while the bearing is hot c) will cause the bearing to become "pitted" d) requires high pressure air e) can not cause damage to or affect our skin in any way Answer A When replacing or removing an antifriction ball bearing, the applied force should a) not be transmitted through the bearing balls b) always be against the inner race c) always be against the outer race d) be applied suddenly and fully e) be made only after heating the bearing Answer E Applying installation forces through the balls of a bearing can cause a) bearing misalignment b) false brinelling c) cracking or breaking of the balls d) improper lubrication e) brinelling Answer D A normal antifriction bearing temperature operating range is a) 150 to 160 degrees C b) 120 to 250 degrees C c) 20 to 50 degrees C d) 65 to 70 degrees C e) 80 to 120 degrees C Answer B When grease is used in an antifriction bearing, the bearing housing should not be filled more than __________ full. a) 1/4 b) 1/3 c) 1/2 d) 3/4 e) completely Answer D Causes of anti-friction bearing failures are: 1. improper fitting 2. false brinelling 3. high operating temperature 4. poor quality lubricant a) 1, 3, 4 b) 2, 3, 4 c) 1, 2, 3 d) 1, 2, 3, 4 e) 3, 4 Chapter 95 Oil Burners for Heating Boilers Answer D The reducing of oil into very small particles is termed a) fluidization b) fractionation c) turbulence d) atomization e) distillation Answer B Before atomization can occur, heavy oils are heated to approximately a) 203 degrees C b) 95 degrees C c) 115 degrees C d) 75 degrees C e) 150 degrees C Answer E An air atomizing burner utilizes an air pressure of approximately a) 15 kPa b) 150 kPa c) 75 kPa d) 95 kPa e) 100 kPa Answer D An air atomizing compressor is usually a) a variable displacement type b) a centrifugal type c) an axial type d) a positive displacement type e) a regenerative type Answer A The capacity of a constant capacity mechanical atomizer is a function of a) orifice size b) pump speed c) pump size d) supply pressure e) oil viscosity Answer B A modulating pressure atomizer has its return oil flow regulated by a) a modulating valve to the burner b) a modulating valve in the return line c) a solenoid valve in the return line d) a temperature control valve to the burner e) pump speed Answer A To which of the following oil burners is the oil supplied under high pressure? a) mechanical atomizing burner b) air atomizing burner c) rotary cup burner d) steam atomizing burner e) multi-spud burner Answer C When using mechanical fuel oil atomization a) 70 kPa steam pressure is required at the burner b) 35 to 40 kPa oil pressure is required c) high pump pressure is required d) steam pressure is required to keep the bypass open e) dry saturated steam or superheated steam should be used Answer A Oil burners can be divided into three classes: 1. air and steam atomizing burners 2. mechanical or pressure atomizing burners 3. centrifugal or rotary cup burners 4. atmospherical pressure burners 5. gravitational pressure burners a) 1, 2, and 3 b) 1, 2, and 4 c) 2, 3, and 4 d) 3, 4, and 5 e) 2, 3, and 5 Answer B The compressed air used as atomizing air in the air atomizing oil burner is also called a) secondary air b) primary air c) pre-mixed air d) pre-compressed air e) post-copressed air Answer B The two basic varieties of mechanical atomizing oil burners are: 1. variable capacity burner 2. constant capacity burner 3. modulating burner 4. stationary burner a) 1 and 3 b) 2 and 3 c) 3 and 4 d) 1 and 5 e) 4 and 5 Answer D A multi-burner cluster has secondary and tertiary nozzles ignited by a) an igniter spark b) an intermittent pilot flame c) an interrupted pilot d) the primary burner e) a continuous pilot Answer B When a greater than normal amount of combustible mixture is ignited the result may be a) a boiler explosion b) a puff-back c) a negative furnace pressure d) a too rapid boiler warm-up e) liquid fuel entering the furnace Answer C A fuel filter consists of a) a cartridge b) wool felt c) three main parts d) a Y-strainer e) a canister Answer D Burner light oil supply pressure range is approximately a) 50 to 100 kPa b) 150 to 250 kPa c) 300 to 550 kPa d) 550 to 700 kPa e) 700 to 850 kPa Answer B A relief valve is placed on the discharge of a fuel oil pump a) because the pump is a dynamic type b) so burner design pressure is not exceeded c) so burner capacity is maintained d) to prevent pump rupture e) to prevent over-firing of the boiler Answer B A time delay oil valve a) opens when the pump starts b) opens once ignition is verified c) opens on flame failure d) is located on the return line e) is upstream of the pressure regulating valve Answer C In order to prevent the possibility of a furnace explosion it is important that the furnace is __________ before the igniter is energized and fuel is supplied to the burner nozzle(s). a) pre-heated b) post-heated c) purged d) cooled e) pressurized Answer E Intermediate and high fire burner nozzles have higher capacities than the primary burner nozzle a) to give greater firing variations b) to prevent pressure surges c) to prevent ignition puff-backs d) because of the pump being of the positive displacement type e) to allow better boiler warm-ups Answer A Oil flow rate to a modulating burner is regulated by a) a return line modulating valve b) a PRV on the burner line c) pump speed d) pump capacity e) firing rate Answer C The minimum distance from furnace to oil storage tank is a) 7 m b) 5.2 m c) 2.1 m d) 4.7 m e) 9.8 m Answer E Maximum static pressure in a fuel oil line is approximately a) 10 kPa b) 15 kPa c) 80 kPa d) 35 kPa e) 70 kPa Chapter 96 Gas Burners for Heating Boilers Answer C The main function of a gas burner is a) atomization of the fuel b) a source of ignition c) provision of O -fuel contact 2 d) regulation of the fuel flow e) air flow control Answer B An atmospheric burner has air entering around the burner which is termed a) primary air b) secondary air c) atomizing air d) combustion air e) tertiary air Answer D The amount of pre-mix air to an atmospheric burner should be a) 10 to 12% b) 5 to 8% c) 20 to 30% d) 30 to 40% e) 40 to 50% Answer A A refractory burner disadvantage is a) high initial cost b) too much fuel preheat c) low radiant heat d) low combustion efficiency e) overheating of boiler metal Answer A A very popular packaged boiler gas burner is the a) ring burner b) non-articulated burner c) post mix atmospheric burner d) mechanical atomizing burner e) cluster nozzle burner Answer D An atmospheric burner head which is very popular on heating boilers is the a) refractory type b) star type c) ring type d) rectangular type e) ribbon ring type Answer A When a gas fired burner is burning fuel properly a) it will have a blue flame with short yellow tips b) the furnace will pulsate c) there will be no turbulence d) it will have a long bright yellow flame e) the induced draft fan can be shut off Answer D Gas burners for heating boilers can be divided into two general classes and they are the a) pre and post turbulence burners b) before and after burners c) pre and post purge burners d) pre and after mix burners e) pre and post combustion burners Answer B The Venturi tube in the atmospheric burner mixing head has a a) gradually decreasing cross-sectional area b) gradually increasing cross-sectional area c) sharply decreasing cross-sectional area d) sharply increasing cross-sectional area e) uniformly distributed cross-sectional area Answer E __________ burner heads are most common for use in heating boilers. a) Oval b) Circular c) Semi-circular d) Triangular e) Rectangular Answer B One of the advantages of the refractory (gas) burner is the a) low cost b) gas and air mixture is thoroughly preheated before it enters the furnace c) flue gases are recirculated back to the furnace to increase the furnace temperature d) flue gases are thoroughly post-heated before they leave the furnace e) flame is directed to areas where it is needed the most Answer D The purpose of the deflector vanes in the centre of a ring (gas) burner is to a) atomize the gas particles b) increase the gas velocity c) decrease the air velocity d) promote turbulence of the gas and air mixture e) increase the temperature of the furnace Answer A One of the advantages of using natural gas as a fuel in a boiler is a) that no storage space is required b) the low cost c) the abundance in supply d) the portability e) that no transmission lines are required Answer C An intermittent pilot a) lights the main flame then extinguishes b) must be manually ignited c) lights the main flame and remains on with it d) remains on when the main flame extinguishes e) lights a pilot flame then extinguishes Answer C The pilot burner for gas fired heating equipment can be: 1. manual 2. continuous 3. intermittent 4. interrupted 5. automatic a) 1, 2, and 3 b) 2, 3, and 5 c) 2, 3, and 4 d) 3, 4, and 5 e) 1, 2, and 5 Answer E The __________ pilot is most often used on small boilers. a) interrupted b) intermittent c) automatic d) manual e) continuous Answer D Large capacity burners a) require high flow on ignition b) are very safe relative to puff-back c) require only a small pilot flame d) should have minimum flow on ignition e) are too hazardous and not recommended Answer B A hydramotor valve a) opens and closes quickly b) helps to prevent puff-backs c) uses air as its working medium d) should not be the last fuel valve to open e) closes slowly Answer A A solenoid type fuel valve a) is held closed by fuel pressure b) always opens rapidly c) is held closed by electrical current d) closes slowly e) does not have positive shut-off Answer B If the power is cut off to an automatic gas valve, the valve will be a) closed slowly b) closed immediately c) closed slightly d) closed half-way e) opened widely Answer A The advantage of a motorized (hydramotor) gas valve is that the valve opens __________ thus preventing "furnace puff". a) slowly b) quickly c) immediately d) slightly e) half-way Chapter 97 Basic Fittings for Low-pressure Steam Boilers I Answer C A function of a Bourdon tube gage hairspring is a) return the tube to its zero position b) keep the pointer on zero c) eliminate backlash d) return the pointer to zero e) eliminate pointer linearity Answer A An LP steam pressure gage range shall be between a) 210 and 420 kPa b) 300 and 450 kPa c) 200 and 500 kPa d) 210 and 460 kPa e) 150 and 300 kPa Answer E An inspectors' test connection a) should be located upstream of a siphon b) should be of 12.7 mm NPT size c) is required on all boilers d) shall be located adjacent to the gage e) is not mandatory on LP boilers Answer D When installing a siphon it a) must be perpendicular to the piping b) must be dry c) should be downstream of an inspectors' test connection d) should be first filled with water e) shall be as close to the boiler as possible Answer B An indication of a pressure gage not performing properly is a) the needle fluctuating b) the needle not returning to zero on depressurizing c) a dial which rotates d) a reading which is not the same as some other gage e) the safety valve popping when gage reads normal Answer A When using a dead weight tester, the effect of friction a) is reduced by rotating the platform b) will cause a higher than desired reading c) is negligible d) is eliminated with a lubricant e) is compensated for mathematically Answer D The working medium in the dead weight tester is a) air b) water c) heavy oil d) medium weight oil e) alcohol Answer D An essential fitting between the boiler and the steam pressure gage is a) a check valve b) a gate valve c) a gage glass d) a siphon e) a steam trap Answer E A steam pressure gauge is graduated in a) pascals b) pascals per square metre c) kilograms per square centimetre d) kilograms per hour e) kilopascals Answer C The prime importance of boiler fittings are a) economics b) efficiency c) safety d) convenience e) ease of operations Answer A All boiler fittings not properly or clearly identified should be a) rejected b) used for low pressure services only c) used for low temperature services only d) used for supplying low pressure water to softeners e) accepted for a lower pressure or temperature rating Answer C The purpose of the test connection on a boiler pressure gauge is to a) unplug the siphon tube b) test a sample of steam for purity c) install the boiler inspector's pressure gauge d) inject live steam to the gauge e) vent air from the pressure gauge Answer A As the boiler pressure increases, the bourdon tube of the pressure gauge will a) tend to straighten b) compress more c) become less circular in cross-section d) become smaller in diameter e) tend to twist Answer E The cross-section of a Bourdon tube is generally a) circular b) round c) cylindrical d) spherical e) oval Answer D An essential fitting between the boiler and the steam pressure gauge is a a) check valve b) gate valve c) gauge glass d) siphon e) steam trap Answer C The purpose of the pipe siphon installed between the boiler and the pressure gauge is to prevent a) air from entering the gauge b) water from entering the gauge c) hot steam from entering the gauge d) air from entering the boiler e) hot steam from entering the boiler Answer A According to the ASME code, the scale on the dial of the steam gauge for a low pressure steam heating boiler shall be graduated to not less than a) 210 kPa b) 420 kPa c) 510 kPa d) 640 kPa e) 720 kPa Answer B According to the ASME code, the scale on the dial of the steam gauge for a low pressure steam heating boiler shall be graduated to not more than a) 210 kPa b) 420 kPa c) 510 kPa d) 640 kPa e) 720 kPa Answer B An LP steam boiler safety valve shall not be smaller than a) 110 mm b) 12.7 mm c) 76 mm d) 25.4 mm e) 101.6 mm Answer D In order to ensure a safety valve seats properly, it uses a) seat rings b) a huddling chamber c) a blowdown ring d) guides and bushings e) a test lever Answer A The force of the steam pressure acting on the safety valve disc is a function of a) disc area b) huddling chamber volume c) seat diameter d) percent valve opening e) blowdown ring diameter Answer C The minimum blowdown of an LP safety valve is a) 96% of the set pressure b) 5% of the set pressure c) 14 kPa d) 2 kPa e) 101.3 kPa Answer C Popping pressure of an LP safety valve may be adjusted a) any amount b) no more than the allowed blowdown c) up to 5% d) up to 7.5% e) by anyone Answer D The blowdown on a safety valve is adjusted by turning the a) inspector's seal b) valve disc c) adjusting nut d) adjusting ring e) valve seat Answer C What does the boiler inspector install to prevent tampering with a safety valve setting? a) a restraining order b) a gag c) a seal d) a plug e) a cover plate Answer E The lip on a safety valve a) allows it to close slowly b) is only required if the steam is superheated c) supplies a drain lip for condensate to collect on d) makes the valve stronger e) allows it to "pop" open Answer D A safety valve on a steam heating boiler must not be smaller than a) 25 mm b) 19 mm c) 38 mm d) 13 mm e) 30 mm Answer D According to the ASME code, steam heating boilers shall have one or more safety valves, adjusted and sealed to discharge at a pressure not exceeding __________ kPa. a) 100 b) 101 c) 110 d) 103 e) 105 Answer A According to the ASME code, the valve seat diameter of the safety valve on a steam heating boiler must not be smaller than a) 12.7 mm (1/2 in.) b) 25.4 mm (1 in.) c) 38.1 mm (1 1/2 in.) d) 50.8 mm (2 in.) e) 63.5 mm (2 1/2 in.) Answer E According to the ASME code, the valve seat diameter of the safety valve on a steam heating boiler must not be larger than a) 25.4 mm (1 in.) b) 38.1 mm (1 1/2 in.) c) 50.8 mm (2 in.) d) 63.5 mm (2 1/2 in.) e) 110 mm (4 1/2 in.) Answer E For a steam heating boiler, the safety valve shall be such that, with the fuel burning equipment installed and operated at maximum capacity, the pressure cannot rise more than ___________ kPa above the maximum allowable working pressure when all steam outlets are closed. a) 103 b) 101 c) 100 d) 55 e) 34 Answer D The safety valve shall be installed in __________ position and located in the highest practicable part of the boiler proper. a) the highest b) the lowest c) a mid d) a vertical e) a horizontal Answer C An LP safety valve lever test should be performed a) weekly b) semi-annually c) monthly d) daily e) quarterly Answer C LP boiler safety valves can be repaired a) only when authorized by the inspector b) by anyone qualified to do so c) by a qualified boiler operator after permission from the inspector d) by a licensed boiler operator e) by only the manufacturer Answer B An operator should check that a boiler safety valve will open at its set pressure by a) sending for the inspector to bring his or her test gage b) increasing the boiler pressure until the valve opens and noting the pressure on the pressure gage when the valve opened c) putting a piece of pipe over the lifting lever and lifting the valve off its seat when the seat pressure is reached d) connecting the boiler to an air compressor during shut down and raising the pressure in the boiler until the set pressure is reached e) listening to the alarms of the set pressures Answer B Testing the safety valve by means of the try lever method, is considered good practice when carried out on a a) weekly basis b) monthly basis c) six monthly basis d) yearly basis e) bi-weekly basis Answer C If a safety valve leaks after a try lever test, the operator should a) plug the safety valve outlet b) reduce the boiler pressure c) operate the try lever several times to blow away foreign material d) fit a gag to the safety valve e) reduce boiler pressure and call the team leader Answer D If you found the safety valve on your heating boiler stuck in the closed position while the boiler was in operation, the best thing to do is a) tap it gently with a bronze hammer to free it b) reduce the boiler pressure and continue operating c) report it to the shift team leader d) shut down the boiler and repair or replace the safety valve e) put the boiler on hand control and notify the inspector Chapter 89 Low-water Fuel Cutoffs Answer C A float operated low-water fuel cutoff has its switch separated from boiler pressure by a) a float cage b) a mercury envelope c) a flexible diaphragm d) a siphon e) packing Answer B A mercury switch bulb is under high vacuum and contains inert gas a) so it will not explode b) to prevent corrosion of the contacts c) to decrease electrical resistance d) so contacts will not overheat e) because the switch is normally closed Answer C A float operated level control a) will recognize swell and shrinkage and correct the feedwater flow b) will have the float in the boiler drum c) is only used on small boilers d) is used on firetube boilers only e) must be used when a boiler is manually operated Answer A Overheating of boiler heating surfaces due to low water a) is the main cause of boiler failure b) will cause a furnace explosion c) can be eliminated with a low-water fuel cutoff d) cannot occur if the boiler is a hot water unit e) can be prevented with proper water treatment Answer D A low water fuel cut-off is fitted to a boiler to prevent a) damage to the radial stays in the steam dome b) the fire from shutting off too quickly and damaging the boiler c) shutting off the water when there is no fuel d) damage to the boiler from an overheated condition e) damage to the boiler from over pressure Answer E The purpose of a low water fuel cut-off is to a) shut off the feedpump when the water level gets too high b) shut off the fuel supply when the burner flame goes out c) shut off the fuel supply when the water pressure is too low d) start the stand-by feedwater pump when level is low e) shut off the fuel supply when the water level gets too low Answer A A low water fuel cut-off may be activated by a) lowering the water level in the boiler b) lowering the water level with the try cocks c) lowering the water level in the gage siphon d) lowering the water with the surface blowdown e) lowering the water level in the sight glass Answer E The CSA code states that a boiler not under continuous attendance must be equipped with a low-water fuel cutoff which a) must be a normally open switch b) can also activate an alarm c) may be equipped with isolation valves d) must be a manually reset device e) serves no other purpose Answer A A low-water fuel cutoff which serves no other purpose a) cannot be equipped with isolation valves b) must be a normally closed switch c) must be a manually reset switch d) must be a float activated switch e) cannot be an electrical conducting type Answer C A low-water fuel cutoff switch should close the automatic fuel valve(s) when the water level is a) at the lowest permissible water line b) at the lowest visible water line c) 1 to 2.5 cm above the bottom gage glass nut d) 1 to 2.5 cm below the gage glass nut e) 76 mm above the lowest permissible water line Answer B A hot water boiler low-water fuel cutoff a) should be tested weekly during routine boiler operation b) cannot be tested during routine boiler operation c) cannot be tested d) should be located on the expansion tank e) must have a normally closed switch Answer C The drain of a hot water boiler low-water fuel cutoff should be opened to flush out any debris a) annually b) daily c) weekly d) monthly e) each shift Answer B To test a low water fuel cut-off a) call for an electrician who specializes in boiler controls b) lower the water level until the burner shuts down c) connect an ammeter to the mercury switch d) test the water column with a test gage e) shut off the fuel to the boiler Answer A The float chamber of the low water cut-off is blown out often to prevent a) the chamber collecting sediment b) the electric wiring from deteriorating c) the mercury from oxidizing d) the magnets rusting e) water hammer to the chamber Answer C The most reliable method of checking or testing a low-water fuel cut off is to a) manually trip the cut-off linkage to shut off the burner b) blow the float chamber down to see if the burner will cut out c) lower the water in the boiler to the level where the burner should cut out d) blow the low water cut-off down through the water column until the burner cuts out e) blow down the sight glass to see if the burner goes out Answer C The low water cut-off can be tested by a) raising steam pressure b) shutting off the fire c) shutting off the feedwater d) opening the safety valve e) closing the steam discharge valve Chapter 98 Basic Fittings for Low-pressure Steam Boilers II Answer C LP steam boilers must be equipped with a marker indicating the a) maximum water level line b) low water fuel cut-off line c) lowest permissible water line d) lowest visible water line e) fireline Answer D A gage glass may be surrounded by a number of thin rods a) when the boiler is a high pressure unit b) to protect the operator from injury c) to prevent cold draft damage d) to protect the glass from damage e) if the glass is attached to a water column Answer E Quick-closing gage glass valves a) prevent loss of water automatically should glass rupture b) should be installed on all boilers c) will not permit gage glass blowdown d) are designed to prevent operator injury e) require 90 degrees for full travel Answer B A disadvantage of a gage glass safety-shutoff valve is a) the glass cannot be blown down b) it requires more maintenance c) it cannot withstand high pressure d) loss of water is not prevented e) it makes gage glass replacement more difficult Answer D Should the steam line or water line to a gage glass become plugged with sludge a) gage glass level will drop in both cases b) gage glass level will drop in the first case and rise in the second c) gage glass level will remain where it was d) the gage glass will read high e) gage glass level will rise in the first case and drop in the second Answer B Water column supply line crosses will a) permit piping inspection b) allow for piping cleaning and inspection c) replace safety shut-off valves d) be installed only on boilers not under continuous supervision e) prevent gage glass blowout Answer B Gage glass rupture may be caused by a) maximum allowable boiler pressure b) a cold draft c) a sudden pressure drop d) warming the boiler up too quickly e) improper boiler water treatment Answer D When gage glass nuts are leaking a) the gage glass should be replaced b) they should be tightened immediately c) new packing should be installed d) the glass should be isolated and depressurized before tightening e) they should be replaced Answer A When the water connection between boiler and gage glass becomes plugged, the water level in the glass will show a level after a while, that is a) higher than the level in the boiler b) lower than the level in the boiler c) the same as the level in the boiler d) fully filled e) lower than the bottom of the sight glass Answer A The lowest visible part of the water gauge glass shall be at least __________ mm above the lowest permissible water level recommended by the manufacturer. a) 25 b) 50 c) 75 d) 100 e) 125 Answer D The ASME code states that each steam boiler shall have one or more water gauge glasses attached either directly to the boiler or to a water column by means of valve fittings not less than __________ mm pipe size. a) 75 b) 51 c) 24 d) 13 e) 10 Answer B On a multiple steam boiler heating system, a stop valve must be placed at each boiler outlet to a) permit slower system warm-ups b) allow boiler isolation from the system c) prevent steam from entering another boiler d) allow each boiler to supply only a part of the system e) permit different system pressures Answer A Boiler outlet valves are usually a) gate valves because of their low resistance to flow b) gate valves because of the ability to control flow c) globe valves because of their throttling capability d) globe valves because of their low flow resistance e) installed in tandem Answer B An outside screw and yoke valve a) is always a gate valve b) readily shows its operating position c) is difficult to lubricate d) requires no packing e) has a non-rising stem Answer B The quick closing valves on the water gauge requires only a/an __________ of a turn of the valve spindle to change the valve from the full open to the full closed position and vice versa. a) eighth b) quarter c) one-third d) fifth e) half Answer D The feedwater pipe, before it enters the boiler must be fitted with a __________ valve adjacent to the boiler. a) stop b) gate c) globe d) check e) plug Answer E A boiler feedwater stop valve a) should never be used to control water level b) is used to isolate the deaerator c) should be a globe valve d) should be located close to the feedwater pump e) is used to isolate the feedwater line Answer B A globe valve should be used in the feedwater line a) at all times b) whenever it may be used for control purposes c) if it is of the OS&Y type d) when the system is of multiboiler installation e) because of its low flow resistance Answer B A stop valve is fitted between the boiler and the feed water check valve a) to regulate the feedwater to the water column b) for isolation and to provide a positive shut-off c) if the boiler is a hot water boiler d) if the boiler is gas fired e) to provide feed water regulation to the boiler Answer D Boiler water foaming may be the result of a) low pH b) excessive blowdown c) low TDS d) high TDS e) dissolved gases Answer C Boiler blowdown lines have a specific size range based on a) water impurities b) the amount of blowdown required c) boiler capacity d) operating pressure e) line length Answer B Boiler blowdown piping a) can be reduced in size after the blowdown valves b) must be full size to the point of discharge c) must be at least 51 mm in size d) can have valves of a smaller size than piping e) may discharge to the sewer system Answer C A steam boiler is blown down in order to a) clean the soot and carbon out of the firebox and tubes b) lower the operating water level in the boiler c) discharge sediment and scale forming matter from the boiler d) test the rated relieving capacity of the safety valves fitted to the boiler e) locate the steam level Answer D The purpose of the small vent valve or cock located on top of the shell or on top of the water column on most boilers is a) to allow water to escape from the boiler when the boiler is being filled with air b) to allow air in to the boiler when the boiler is being filled with water c) to allow water to escape before the steam stop valve is opened during the warm-up period d) to allow air to escape from the boiler when the boiler is being filled with water e) to allow water into the boiler when the boiler is being drained or cooled preventing the formation of a vacuum Chapter 99 Basic Fittings for Hot Water Boilers Answer C A pressure or altitude gage for a hot water boiler a) must be equipped with a siphon b) shall have a dial scale at least 3 times the maximum allowable working pressure c) does not require a siphon d) must have a temperature dial e) must be of 51 mm pipe size Answer A When a closed expansion tank is used and the system is cold a) the auto fill valve will maintain a system minimum pressure b) the tank level will be high c) there will be no air in the tank d) the possibility of air in the system will be high e) the tank should be manually filled Answer D An altitude gage on hot water heating boilers is used to indicate a) expansion tank temperature b) boiler temperature c) furnace draft d) height of the highest radiator in system e) the height of the boiler Answer D Siphon is not required between a pressure or an altitude gauge and a hot water boiler since these boilers are a) filled with steam b) partially filled with steam c) partially filled with air d) filled with water e) filled with water and air mixtures Answer B The lever handle of the shut-off cock between a pressure or altitude gauge and a hot water boiler should be __________ to the pipe in which it is located when the cock is open. a) perpendicular b) parallel c) adjacent d) opposite e) tangent Answer A The scale on the dial of a pressure gauge should be graduated to not less than __________ times the maximum allowable working pressure. a) 1.5 b) 2.0 c) 2.5 d) 3.0 e) 3.5 Answer E The dial of a pressure gauge on a hot water boiler indicating SI units can be graduated in a) metres of mercury b) mm of water c) mPa d) psi e) kPa Answer E When the pressure pointer of a closed system reads lower than the altitude pointer the a) system is full of water b) expansion tank level will be high c) boiler is being over-fired d) gage is faulty e) system requires water Answer D The temperature indicator of a hot water boiler should indicate water temperature a) at the boiler inlet b) in the expansion tank c) midway through the system d) at the boiler outlet e) in the boiler Answer B On a pressure temperature indicator, if the pressure pointer falls below the altitude pointer a) the atmospheric pressure is low b) the system is low on water c) the boiler is too full d) the water is too hot e) the water is too cold Answer A Hot water heating boilers must be equipped with a a) thermometer b) fusible plug c) return trap d) blow down tank e) steam pressure gage Answer E With the fusible plug type of temperature relief device, the fusible plug will melt at __________ degrees Celsius and allow hot water to escape. a) 131 b) 121 c) 101.3 d) 100 e) 99 Answer D The expansion and contraction rod type of temperature relief device will open the valve at __________ degrees Celsius and close it at __________ degrees Celsius. a) 99 and 80 b) 100 and 71 c) 101.3 and 75 d) 99 and 71 e) 100 and 80 Answer B A boiler pressure relief valve a) shall be installed on the boiler b) can be installed anywhere in the system but preferably close to the expansion tank c) must be at least 51 mm pipe size d) does not require annual checking or testing e) can be installed with an isolation valve Answer A For hot water boilers operating up to 414 kPa, a pressure relief valve opening pressure variation may be as much as a) 14 kPa b) 5% c) 14% d) 5 kPa e) 10% Answer E A hot water boiler is protected from over pressure by means of a) a safety pop valve b) a high limit pressure control c) an expansion valve d) an air release valve e) a safety relief valve Answer A ASME Section IV, states that each hot water heating boiler shall have at least one officially rated pressure relief valve set to relieve at or __________ the maximum allowable working pressure of the boiler. a) below b) 6% above c) 1.5 times d) twice e) 10% above Answer E Hot water boilers have stop valves in their inlet and outlet piping a) to allow for better warm-ups b) to prevent water from entering another in-service unit c) so that each boiler can have separate water treatment d) to permit annual maintenance e) so that the boiler can be drained without draining the system Answer C Boiler stop valves shall be a) of the OS&Y type b) globe valves c) identified with durable tags d) installed on horizontal piping e) throttled during operation Answer B During warm-up of a cold hot water boiler excessive pressure build-up is prevented by a) a very slow warm-up b) an expansion tank c) a pressure relief valve d) opening the boiler outlet valve e) venting the system Answer D In a closed expansion tank system an air separator a) removes air from the system b) is installed at the boiler inlet c) is installed at the boiler outlet d) directs air into the expansion tank e) is not required Answer C In a hot water heating system, the closed type expansion tank should be a) kept full of water b) open to the atmosphere c) partly filled with water d) isolated from the system e) closed and independently heated Answer B When a closed type expansion tank on a hot water boiler is completely filled with water and the water in the system is raised in tempera- ture so that it expands, the result will be that a) the boiler expands b) the pressure build-up opens the safety relief valve c) the heating system becomes noisy d) the circulating pump will stop e) the expansion tank will expand Answer C An expansion tank is used to a) store steam b) increase water temperature c) allow for the expansion of the water d) provide more efficient water circulation e) allow free expansion of the steam Answer D The head of water in the hot water heating system employing an open type of expansion is referred to the vertical distance from the gauge of the boiler to the level in the __________, which is considered the highest level of the water in the system. a) steam drum b) top row of tubes c) auto-fill valve d) expansion tank e) hot water outlet valve Answer C An automatic fill valve a) will maintain maximum system pressure at all times b) is a mandatory fitting c) is not mandatory d) opens only when expansion tank level is low e) can be used with an open tank system Answer A A closed expansion tank is usually equipped with a) a gage glass b) a pressure relief valve c) an automatic fill valve d) a circulating pump e) a thermometer Chapter 100 Hot Water Steam Heating Boiler Operations Answer B Before starting up a new boiler or one that has been out of service the following must be ensured a) the manufacturer's recommendations are read b) the boiler has a valid inspection certificate c) the fuel is shut off d) the boiler control is in the OFF position e) the boiler is cold Answer D It is very important that boilers should be a) warmed up quickly to prevent condensation b) warmed up quickly to prevent scale build-up c) lit only when cool d) warmed up slowly to prevent thermal shock e) warmed up at a rate of one degree every five minutes Answer A When cutting in an additional boiler into the heating system a) the stop values in the supply and return lines are both closed b) the supply valve is open slightly, the return line closed c) the supply and return lines are open d) the supply valve only is closed e) the supply and return line valves are both open slightly Answer D One of the most important points that should be observed before a new boiler is started and put into continuous operation is to a) check and make sure all valves are opened b) check and make sure all valves are closed c) make sure the vent is in the open position d) make sure the inspection certificate is valid e) make sure the startup is on schedule Answer D When preparing a boiler for startup and the boiler is equipped with a modulating combustion control, it is best to a) set the manual-auto switch to "auto" b) set the manual-auto switch to "auto" and set the flame control switch in the lowest position c) set the manual-auto switch to "auto" and set the flame control switch in the highest position d) set the manual-auto switch to "manual" and set the flame control switch in the lowest position e) set the manual-auto switch to "manual" and set the flame control switch in the highest position Answer B If the low-water fuel cutoff and/or the high limit control are equipped with a trip-out device on a boiler, it is recommended as part of the startup preparation to a) dismantle the device and check for lose wires b) push the reset button to assure that the switches are closed c) check the low-water fuel cutoff and make sure all the mercury switches are working properly d) check that the high limit switches are set high enough e) dismantle the high limit switches and overhaul if necessary Answer D In hot water boiler operation the maximum operating temperature should never exceed a) 77 degrees C b) 87 degrees C c) 100 degrees C d) 121 degrees C e) 131 degrees C Answer C The pressure relief valve on a hot water heating boiler should be set a) 25% lower than operating pressure b) 10% lower than operating pressure c) 25% above operating pressure d) 20% lower than operating pressure e) at the operating pressure Answer C A gradual increase in stack temperature is an indication of a) poor burner operation b) too much excess air c) unclean heating surfaces d) poor damper operation e) all of the above Answer D The discharge pressure of steam heating pressure relief valves should never exceed a) 14.7 kPa b) 121 kPa c) 93 kPa d) 103 kPa e) 153 kPa Answer A How often would you test the low level fuel cut-off on a low pressure steam heating boiler by blowing out the float chamber? a) daily b) monthly c) semi-annually d) annually e) bi-weekly Answer E Should any abnormal condition occur during light-off or the temperature building-up period a) continue to run the boiler but reduce the steam and fuel valve settings b) stop running the boiler immediately and open the vent valve c) stop running the boiler immediately and open the feedwater valve d) continue to run the boiler but reduce the load and close the steam valve e) shut down the boiler immediately and close the stop valves in the fuel lines Answer C There are two conditions that may occur during the warm up period which may seem to be abnormal to the operator but will disappear after the boiler heats up. These conditions are a) uneven expansion and thermal shock b) fluctuation of water and steam pressures c) slight smoking and condensation d) high stack and hot water/steam temperature e) low stack and hot water/steam temperature Answer B During the warm-up period of a heating boiler the main burner goes out. The operator should a) shut down the boiler immediately, purge the boiler, and restart it. b) shut down the boiler, close the fuel valves, and determine the cause of the problem c) try to re-light the burner immediately d) check the altitude gage to ensure there is enough water in the system e) clean the burner, purge the boiler, and restart it Answer E Thermal shock to boilers can be reduced by a) warming up boilers slowly b) keeping the boiler free of scale build-up c) covering the tube sheets with refractory d) not allowing full flow of cold water into a warm hot water boiler e) all of the above Answer B The most important rule in safe operation of a steam heating boiler is a) operate the burner properly b) keep the water level in the boiler at the proper level c) maintain the proper operation of automatic controls d) maintain the correct level in the altitude gage e) ensure air is kept out of the system Answer B To reduce the effects of uneven expansion and thermal shock and to protect a boiler against damage during startup, one of the precautions that should be taken is a) always heat up the boiler quickly b) always warm up the boiler slowly c) make sure the vent is opened d) make sure the steam is closed e) always open the fuel valve slowly Answer D It is recommended that the differential between the safety relief valve set pressure and the operating pressure of a hot water boiler be kept to a minimum of 69 kPa (10 psi) or __________ % of the relief valve setting. a) 10 b) 15 c) 20 d) 25 e) 30 Answer A Smoking conditions during the operation of a boiler can be caused by a) improper air/fuel ratio b) steam demands too great c) low water conditions d) too much combustion air e) not enough fuel Chapter 101 Steam Heating Equipment Answer C Unit heaters differ from convectors in that they use _______ to increase heat transfer. a) metal fins b) natural circulation c) blowers d) copper tubes e) brass tubes Answer A Convectors use ________ to increase heat transfer. a) metal fins b) radiators c) blowers d) copper tubes e) brass tubes Answer C In fin coil type heaters, individual room temperature is controlled by a) switches b) automatic valves c) dampers d) air relays e) supply ducts Answer D Unit ventilators use a) only outside air for heating b) only inside air for heating c) natural draft d) a mixture of inside and outside air e) fin coil heaters Answer D The difference between a convector and a radiator is a) the way they transfer heat b) the way the heating medium goes through c) the method of control d) that one is made of cast iron and the other of steel or copper e) the way the heating and cooling is distributed Answer A Large areas such as warehouses, are usually heated with a) unit heaters b) radiators c) convectors d) open heaters e) space heaters Answer A Air can be removed from steam heating systems by a) air vents b) a steam trap c) an air separator d) an air header e) a dip tube Answer E A radiator valve is used to control the amount of a) air leaving the radiator b) condensate leaving the radiator c) steam leaving the radiator d) air entering the radiator e) steam entering the radiator Answer E A radiator trap is a device that is used to a) allow only air to leave the radiator b) vent steam from the radiator c) depressurize a radiator d) allow only steam to leave the radiator e) allow only water to leave the radiator Answer C The vacuum pump performs the following function: a) supplies water to the condensate receiver b) supplies steam to the boiler c) returns the condensate (water) back to the boiler d) returns the condensate water to the condensate receiver e) none of the above Answer A The level in the condensate receiver is automatically controlled by a a) float switch b) pressure reducing valve c) gate valve d) drain valve e) sight glass Answer C The purpose of a radiator trap is to a) control steam flow into the radiator b) control steam flow leaving the radiator c) drain condensate from the radiator d) remove the air from the radiator e) trap the radiant heat in the system Answer B Air vents are used to a) trap excess air b) expel the air from heating systems c) trap volatile liquids d) expel impurities from boilers e) expel the moisture from heating systems Answer E The purpose of a radiator trap is to a) stop the flow of steam b) assist circulation within the radiator c) control the temperature of a radiator d) enable the radiator to be isolated e) pass condensate and retain steam in the radiator Chapter 102 Steam Heating Systems Answer C The piping and heating units of a steam heating system must be so arranged that a) the condensate can flow freely to the heating units b) the air can be kept at the top of the heating units c) steam can flow freely to all heating units d) all of the above e) none of the above Answer B In a gravity return system the boiler should be placed a) well above the highest radiator b) well below the lowest radiator c) on an elevated platform d) at the same level as the radiators e) in a central location Answer C The Hartford Loop prevents the water in the boiler from a) exceeding the maximum temperature b) exceeding the highest safe level c) dropping below a safe level d) contamination by impurities in the returning condensate e) flowing out through the steam main Answer A All supply and drain lines of a steam heating system must be pitched to a) allow for drainage of condensate b) allow collection of air at the highest points c) prevent corrosion d) allow for temperature expansion e) all of the above Answer C When starting up a steam heating boiler it should be filled to a) the maximum level b) 3/4 of a gage glass c) 1/2 of a gage glass d) 1/4 of a gage glass e) the very bottom of the gage glass Answer D If the water level falls too low during operation of a steam heating boiler the operator should a) tell his or her supervisor b) add more water immediately c) operate the safety valve d) shut the boiler down e) lower the flame and add water to bring it up to a safe level Answer E In the case of radiators and convectors, the main sources of trouble are the a) air vents b) air traps c) push nipples d) connecting rods e) valves and traps Answer D Finned convectors should be kept free of a) air b) steam c) corrosion d) dust e) all of the above Answer B Slow or insufficient heat throughout a building heated by steam can be caused by a) too high a firing rate b) too low a firing rate c) air leaks d) the feedwater being too cold e) oversized piping Answer A Slow or insufficient heat in one or more rooms in a steam heated building can be caused by a a) faulty steam trap b) faulty float switch c) faulty heater d) faulty vacuum switch e) faulty sight glass Chapter 103 Hot Water Heating Systems Answer C The maximum temperature of water in a gravity hot water system is a) 65 degrees C b) 70 degrees C c) 77 degrees C d) 87 degrees C e) 67 degrees C Answer B In a forced circulation system the expansion tank allows the system to operate at a) a vacuum b) a pressure well above atmospheric pressure c) pressures above sea level d) the lower floors e) absolute pressures Answer E A forced hot water circulating system can be classified as the following type: a) loop system b) one pipe system c) two pipe direct return system d) two pipe reverse return system e) all of the above Answer A In a one pipe hot water system the fitting that directs the water to each converter is called the a) diverter b) trap c) vent valve d) separator e) lead Answer C In a radiant heating system the maximum surface temperature is a) 10 degrees C b) 20 degrees C c) 30 degrees C d) 40 degrees C e) 50 degrees C Answer A In radiant heating system changes are a) difficult to make b) easy to make c) as easy to make as in any other heating system d) dependent on availability of materials e) dependent on location Answer E Automatic snow melting systems can use a) hot water and antifreeze mixed b) electric resistance heating c) infrared lamps mounted above sidewalks and ramps d) hot water and ethylene glycol mixed e) all of the above Answer C Snow melting systems are usually filled with a) water only b) methanol and water c) ethylene glycol and water d) steam e) warm air Answer A Advantages of the forced circulation hot water heating systems are a) reduction in pipe size and greater heat storage capacity b) high pressure piping and controls c) high vacuum in the return lines and pumps d) higher make-up and better chemical control e) low water make-up and better temperature control Answer B A hot water boiler of the same output is a) larger than a steam boiler b) smaller than a steam boiler c) the same size as a steam boiler d) taller than a steam boiler e) shorter than a steam boiler Answer B In a hot water system compared to a steam heating system, if there is a leak damage will a) be greater in the steam system b) be greater in the hot water system c) be about the same in either system d) depend on where the boiler is located in the system e) be minimal due to the automatic drain system Answer E Which of the following use a boiler in the system? 1. steam heating 2. electric heating 3. steam to hot water system 4. hot water heating a) 1, 2 b) 2, 3 c) 1, 4 d) 3, 4 e) 1, 3, 4 Chapter 104 - Hot Water Heating System Equipment and Operation Answer B Diverter fittings are used in the supply lines to heating units a) to compensate for a low heating load b) when a higher heating output is required from the heating unit c) when the distance from the boiler to heating unit is short d) when there are no balancing valves installed in the supply line e) when a hydraulic balance must be corrected Answer A An air separator should always be installed in a) a horizontal pipe b) a cross tee c) a vertical pipe d) an expansion tank e) a converter Answer D The air removed by the air separator is vented to the a) air space at the top of the boiler b) nearest convector c) dip tube d) expansion tank e) relief valve Answer E To ensure that each zone circuit has the proper flow of water to provide the required heat a: a) flow control valve is used b) diverter fitting is used c) gate valve is used d) pressure reducing valve is used e) balancing valve is used Answer D The temperature control on a steam to hot water converter, controls a) the pump speed b) the steam temperature c) the water flow d) the s

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