A.deformed
B.rusted
C.cracked
D.scaled
您可能感興趣的試卷
你可能感興趣的試題
A.in series
B.in parallel
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)vane
(3)gear
A.（1）only
B.（1）and（2）
C.（2）and（3）
D.（1），（2）and（3）
Which of the following will be the advantage of a centrifugal pump as compared with a reciprocating pump?（）
(1) Its discharge is continuous
(2) It has no internal valves
(3) Upon accidental closing of discharge valve, excessive pressure will not build up
A.（1），（2）
B.（2），（3）
C.（1），（2），（3）
D.（2）only
A.reduce
B.rise
C.raise
D.fall
A.increase discharge pressure
B.increase suction vacuum
C.develop pulsation flow
D.keep a steady rate of flow
最新試題
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
Which of the following statements is correct concerning heat transfer?（）
A salinity indicator is used to determine the （）.
Which of the listed pumps is NOT a positive displacement pump?（）
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
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 （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
A salinity indicator is used to determine the （）.
The usual symptoms of cavitation in a centrifugal pump is （）.