when the boiler has been secured long enough for most solids to settle
when the boiler has been cooled to ambient temperature
only after raising the water level to within 0~5 inch of the high water cutout only
after bypassing the low pressure
第1题：
The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to______.
A.precipitate(使沉淀) silica （硅石）from solution
B.reduce corrosion in the heating coil
C.prevent clogging and erosion in the coil
D.maintain zero water hardness
第2题：
will be modulated in proportion
will be modulated in proportion and integral
will be modulated in proportion and differential
will not be modulated at all
第3题：
The correct procedure for giving an auxiliary boiler a bottom blow, is to begin .
A.when the boiler has been secured long enough for most solids to settle
B.when the boiler has been cooled to ambient temperature
C.only after raising the water level to within 0.5 inch of the high water cutout only
D.after bypassing the low pressure
第4题：
when the boiler has been secured long enough for most solids to settle
when the boiler has been cooled to ambient temperature
only after raising the water level to within 0~5 inch of the high water cutout only
after bypassing the low pressure
第5题：
operating the boiler at less than normal water level
installing fins on the firesides of water-tubes
increasing the amount of excess air to the burners
treating the boiler water with chemical oxygen scavengers
第6题：
concentrations of calcium sulfate in the boiler water
fuel oil in the feed water
improper treatment of the feed water with calcium sulfate
excessive feed water alkalinity
第7题：
relieve excess fuel oil pressure during the “off” fire cycle
admit water to the dry pipe
throttle the forced draft fan output for proper combustion
reduce excess steam pressure in the boiler
第8题：
If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.
A.high steam pressure in the boiler
B.abnormally high feed-water temperature
C.abnormally high boiler water temperature
D.steam demand exceeding feed pump capacity
第9题：
steam stop valve
dry pipe
feedwater system
generating tubes
第10题：
remove suspended and precipitated solids from the boiler water
completely drain the boiler in an emergency situation
prevent hardened scale deposits in the water drum
remove floating impurities from the oily water surface