A.draw the liquid in；force the liquid out
B.force the liquid out；draw the liquid in
C.suction；draw
D.deliver；outlet
您可能感興趣的試卷
你可能感興趣的試題
A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is tree
Which of the following pumps are self-priming, and can deal with liquid from a level below the pump? （）
(1) reciprocating
(2) rotary
(3) centrifugal
A.(1)only
B.(1)and (2)
C.(1),(2)and(3)
D.(2)and(3)
A.throttling the pressure line
B.changing the speed of the driving rotor
C.either A or B
D.None of the above is tree
A.throttling the pressure line
B.changing the speed of the piston
C.either A or B
D.None of the above is tree
A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is tree
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 （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
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 （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
When the steering gear is in operation, you should （）.