in series
in parallel
either A or B
None of the above is tree
第1题：
Single stage or multistage
High pressure or low pressure
Open or close coupled
Horizontal or vertical
第2题：
Absorb erosion of high velocity discharge stream
Seal pump shaft against entry of air
Isolate the discharge side from the suction side
Dampen the turbulent discharge flow
第3题：
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.
A.excessive pump speed
B.excessive suction head
C.worn wearing rings
D.gross pump misalignment
第4题：
Classification Society Rules
National requirements
The IMO International Convention for the Safety of Life at Sea
All of the above
第5题：
gear
nonpositive displacement
positive displacement
rotary
第6题：
the mechanical seal
packed stuffing boxes
either A or B
neither A nor B
第7题：
two or more impellers housed together in one casing and mounted on a single shaft
a single stepped impeller mounted in a progressively staged casing
a large radial clearance between the impeller and casing to prevent overheating due to
an increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stages
第8题：
Centrifugal pumps have what advantage（s）over reciprocating pumps ________．
A.They are less expensive
B.They are smaller for equivalent pumping ability
C.They pump more cargo in less time
D.All of the above
第9题：
stuffing boxes eliminate the leakage problems usually associated with other gear pumps
it is not necessary to closely maintain design clearances with this pump
they are essentially self-priming and produce a high suction lift
these pumps are designed with extreme tooth angled
第10题：
They are self-priming
Decreasing the speed of rotation will decrease the discharge pressure
Opening the discharge valve wider will increase the discharge pressure
All of the above