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Which of the following statements concerning fire-tube boilers is correct?（）
A . Combustion gases flow through the tubes
B . Flames impinge on the tubes
C . Combustion occurs in the tubes
D . Water flows through the tube
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The purpose of designing some waste heat boilers with sinuous fire tubes, is to（）
A . increase exhaust gas velocity through the boiler
B . reduce accumulations of carbon deposits on the heat transfer surfaces
C . eliminate exhaust gas pulsations and noise
D . increase the rate of heat transfer to the waterside
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The purpose of a temperature sensing device installed in the stack of a small automatically fired auxiliary steam boiler is to secure the oil burner（）
A . in the event of a flame failure
B . in the event of a stack fire
C . when the water level reach the crown sheet
D . when the feed pump discharge pressure drops to a preset minimum
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Improper maintenance of the fuel oil burners in an automatically fired auxiliary boiler, could result in （）
A . increased fuel consumption
B . increased feed water consumption
C . fuel pump failure
D . combustion control system failure
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When a boiler is operating, the water level in the gauge glass reads （） when the boiler is shut down.
A . lower than
B . higher than
C . as much as
D . the same a
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The valve that prevents water from backing out of the boiler into the feed line is the（）.
A . bottom-blow valve
B . skin valve
C . feed-check valve
D . feed-stop valve
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When there is a flame failure in an automatically fired auxiliary boiler, the （）.
A . air supply is shut off
B . fuel supply is shut off
C . water supply is shut off
D . safety valve lift
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The steam boiler is part of a closed loop steam, whereby, after the energy of the steam is used up and it becomes water again, （） is collected and returned back to the boiler for heating up again to steam.
A . the former
B . the first
C . the latter
D . the last
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Too much air in the furnace of an oil-fired boiler would be indicated by （）.
A . yellowish flame
B . golden yellow flame
C . white flame
D . brilliant white flame
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The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust （）.
A . gas composition
B . gas temperature
C . pressure
D . timing
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A distorted furnace in a fire-tube auxiliary boiler may be the result of （）
A . firing for extended periods in the low fire mode
B . overheating, due to waterside deposits
C . varying the water level above the crown sheet
D . carrying excessive alkalinity in the boiler water
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Which of the following statements concerning the water tube and fire tube boilers is not true?（）
A . natural circulation of the water in the water tube boiler is better than that in the fire tube boiler
B . for the same output the water tube boiler will carry less mass of water compared with the fire tube boiler
C . the water tube boiler will cost shorter time for steam raising
D . the water tube boiler require lower skill in operating and maintaining
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A firebox explosion in an automatically fired auxiliary boiler may be the result of （）
A . excessive purging before lighting off
B . insufficient trail for ignition period
C . a faulty transformer in the ignition circuit
D . insufficient purging before lighting off
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Which one is not the normal operation for boiler shutdown?（）
A . Carry out soot blowing if permissible
B . Change fuel supply to diesel oil
C . Close steam stop valves on boiler when pressure is reduced
D . Drain boiler empty when it has cooled dow
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The fire of sodium is classified as（） fire.
A . Class A
B . Class B
C . Class C
D . Class D
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If a fire occurs in the boiler room as a result of a leaking fuel line, you should FIRST （）.
A . notify the engineer on watch
B . isolate and secure the piping
C . throw sand on the fire
D . extinguish the fire using a combination nozzle with applicator
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The purpose of the safety relief valves installed on an auxiliary boiler is to （）.
A . relieve excess fuel oil pressure during the “off” fire cycle
B . admit water to the dry pipe
C . throttle the forced draft fan output for proper combustion
D . reduce excess steam pressure in the boiler
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The furnace of an oil fired boiler should be （） before the operating burner is lit.
A . filled with water
B . purged
C . cleared of air
D . None of the above is true
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After a normal, or safety shutdown, automatic combustion control systems for an auxiliary boiler are designed to prevent the immediate re-firing of a burner in order for the （）.
A . furnace to be re-purged
B . electric charge to buildup in the igniter
C . fuel pump to restart
D . drum level to stabilize
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The class of fire on which a blanketing effect is essential to extinguish the fire is （）.
A . class A
B . class B
C . class C
D . class D
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The purpose of the programmed purge cycle on an automatically fired auxiliary boiler is to（）
A . cool the furnace to prevent pre-ignition
B . remove explosive vapors from the furnace
C . evaporate accumulated unburned fuel oil
D . provide sufficient air in the furnace to allow ignition of the fuel
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As for an oil-fired boiler if at a normal steaming condition and water goes out of sight in gauge glasses the action you should take is: （） (1) secure oil to fires (2) increase feed pump pressure
A . （1）
B . （1）and（2）
C . （2）
D . neither（1）nor（2）
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The valve that prevents water from backing out of the boiler into the feed line is the______.
A.bottom-blow valve
B.skin valve
C.feed-check valve
D.feed-stop valve
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As for an oil-fired boiler if at a normal steaming condition and water goes out of sight in gauge glasses the action you should take is: (1) secure oil to fires; (2) increase feed pump pressure.
A.(1)
B.(1) and (2)
C.(2)
D.neither (1) nor (2)
