A.protect the pump from fine soluble contaminants
B.prevent solid particles from entering the pump
C.prevent solid particles from entering the filter
D.protect the directional control valves
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A.Feed-water heater internal tube surfaces
B.Internal distillate cooler tubes
C.Flash chamber vertical surfaces
D.Distilling condenser tubes
A.Reduction of friction
B.Insulation of hot surfaces
C.Lubrication of moving parts
D.Elevation of cooler outlet temperatures
A.higher boiling temperature for a given pressure than does a pure refrigerant
B.lower boiling temperature for a given pressure than does a pure refrigerant
C.boiling pressure equal to that of a pure refrigerant at a given pressure
D.boiling point will not be affected by entrained oil
A.Degree of saturation
B.Saturation temperature
C.Superheated temperature
D.Degree of superheat
A.pump must always be primed
B.volute must impart a radial and rotary motion of the water suction side
C.connection must guide the liquid to the lantern rings
D.stuffing box should not be allowed any water leakage
最新試題
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
The general purpose of a heat exchanger is to （）.
When the steering gear is in operation, you should （）.
A salinity indicator is used to determine the （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
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?（）
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.