A.Extensive centrifuging
B.Wax content
C.Water content
D.Acid content
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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
A.loss of second stage vacuum
B.contamination of the distillate
C.lower feed inlet temperature
D.contamination of the second stage condenser
A.total head
B.discharge head
C.net positive suction head
D.suction head
最新试题
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
The general purpose of a heat exchanger is to （）.
Which of the following statements is correct concerning heat transfer?（）
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
The major source of chemical contaminants in hydraulic fluid is （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）