單項(xiàng)選擇題If in doubt as to the true water level when a boiler is being oil-fired, you should ().

A.take no measures
B.extinguish the fire as soon as possible
C.feed water to the boiler
D.open the blow down valve


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1.單項(xiàng)選擇題The boiler feed water check valves are located on the ()

A.feed pump suction line
B.hot well
C.shell of the feed heater
D.feed lines to the boiler

2.單項(xiàng)選擇題The water level in a steaming auxiliary boiler will always ()

A.rise when the steam pressure is increased
B.remain constant as long as the feed pump operates
C.fall when the steam pressure is decreased
D.vary as the steam demand changes

3.單項(xiàng)選擇題The donkey boiler may be given a bottom blow ()

A.to raise water level
B.only while making steam
C.to remove scum
D.when fire are secured

4.單項(xiàng)選擇題When steam is being raised on a boiler, the water level will normally ().

A.drop as the boiler warms up
B.rise as the boiler warms up
C.remain unchanged until the boiler is hot enough
D.rise and fall with the steam demand

5.單項(xiàng)選擇題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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