单项选择题
The most common cause of scale formation in an auxiliary boiler is （）
A.concentrations of calcium sulfate in the boiler water
B.fuel oil in the feed water
C.improper treatment of the feed water with calcium sulfate
D.excessive feed water alkalinity
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相关考题
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单项选择题
For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）
A.High oxygen concentration
B.Low pH
C.Proper alkalinity
D.All of the above -
单项选择题
If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be（）.
A.525 RPM
B.775 RPM
C.1550 RPM
D.1800 RPM -
单项选择题
An indication of a diesel engine air intake being partially clogged, is （）.
A.low firing pressure and low exhaust temperatures
B.low firing pressure and normal exhaust temperatures
C.high firing pressure and low exhaust temperatures
D.high firing pressure and high exhaust temperatures
