A.acid
B.alkali
C.salt
D.None of the above
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A.proper combustion
B.water in the fuel
C.excess air
D.cold fuel oil
A.The safety valve escape piping should be disconnected from the valve body and a blank inserted
B.The boiler vent valves should be opened
C.All hand-hole/manhole covers should be tightened up as much as possible to preclude any leaks
D.All of the above
A.The boiler oil tank
B.The steam pipe
C.The fire side
D.The safety valves
A.oxygen in the water
B.poor boiler design
C.density too high
D.excessive steam demand
A.yellowish flame
B.golden yellow flame
C.white flame
D.brilliant white flame
最新試題
Low compressor head pressure in a refrigeration system can be caused by（）.
When the steering gear is in operation, you should （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
Which of the following statements is correct concerning heat transfer?（）
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
A pressure drop through the refrigerant liquid line may cause （）.
The major source of chemical contaminants in hydraulic fluid is （）.
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 （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
A salinity indicator is used to determine the （）.