A.oxygen in the water
B.poor boiler design
C.density too high
D.excessive steam demand
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A.yellowish flame
B.golden yellow flame
C.white flame
D.brilliant white flame
A.condensate
B.a small amount of make-up feed
C.A and B
D.None of the above
A.yellowish flame
B.golden yellow flame
C.white flame
D.brilliant white flame
A.low water level
B.low oil pressure
C.excessively high fuel pressure
D.an improper air/fuel ratio
A.Reciprocating pump
B.Screw pump
C.Diffuser pump
D.Water-ring pump
最新試題
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
The general purpose of a heat exchanger is to （）.
The major source of chemical contaminants in hydraulic fluid is （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
Which of the following statements is correct concerning heat transfer?（）
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.