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
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
A.discharge is continuous
B.it has no internal valves
C.upon accidental closing of discharge valve, excessive pressure will not build up
D.all of the above are true
最新试题
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
The general purpose of a heat exchanger is to （）.
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 （）.
A pressure drop through the refrigerant liquid line may cause （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
When the steering gear is in operation, you should （）.