A.are exposed to a vacuum
B.come in contact with extremely hot surfaces
C.are reduced in temperature to just above the pour point
D.become extremely agitated or aerated
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A.weight
B.internal friction
C.demulsibility
A.Extensive centrifuging
B.Wax content
C.Water content
D.Acid content
A.Viscosity will increase as temperature increases
B.Viscosity is a measure of a fluid s internal resistance to flow
C.Viscosity will decrease as temperature decreases
D.Viscosity is not dependent on temperature
A.the manual trick wheel is engaged for steering
B.the variable stroke pump is off stroke
C.a rudder order is given by the control system
D.an electric power system failure occurs at the steering gear
A.cool the expansion valve
B.prevent refrigerant superheating
C.condense the refrigerant gas
D.prevent motor overheating
A.Closing of the solenoid valve
B.Closing of the expansion valve
C.An increase in the suction pressure
D.Decreasing the suction pressure
A.When the helm is at any angle other than amidships
B.When the six-way valve is opened
C.When the ram relief valves lift
D.When the redder angle is different from the position of the helm
A.suppressant additive
B.dispersant additive
C.extreme pressure additive
D.viscosity improver additive
A.centrifugal pumps
B.jet pumps
C.propeller pumps
D.reciprocating pumps
A.a compressed packing gland
B.lantern tings between the packing rings
C.a liquid seal
D.the stuffing box gland
最新试题
Which of the listed pumps is NOT a positive displacement pump?()
The general purpose of a heat exchanger is to ().
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?()
The control mode in which the final control element is moved from one of two flexed positions to the other is known as ().
The usual symptoms of cavitation in a centrifugal pump is ().
A salinity indicator is used to determine the ().
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by ().
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?()
If the suction pressure at the refrigeration compressor is below normal, the cause can be().
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by ().