单项选择题
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
相关考题
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单项选择题
Bottom blow valves are installed on auxiliary water-tube boilers to ()
A.completely drain the boiler in an emergency
B.prevent sludge from forming in the drum
C.remove floating impurities from the boiler water surface
D.remove settled solids from the water drum -
单项选择题
A burner responsible for producing black smoke in an automatic auxiliary boiler, would be caused by a ()
A.defective solenoid valve
B.dirty fuel nozzle
C.grounded high tension lead
D.faulty ignition cable connector -
单项选择题
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
