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单选题
Gear pumps are （） because they discharge a near constant amount of liquid regardless of pressure.
A
negative displacement type
B
turbine type
C
positive displacement type
D
mixed-flow type
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单选题Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.A
depending onB
in relative toC
regardless ofD
because of
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The high discharge pressure of the rotary pumps permits a larger volume of fluid per unit time than the reciprocating pumpB
Rotary pumps are capable of pumping more fluid than reciprocating pumps of the same weightC
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it is not necessary to closely maintain design clearances with this pumpC
they are essentially self-priming and produce a high suction liftD
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单选题Air chambers are usually fitted to reciprocating pumps in order to （）.A
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keep a steady rate of flow
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单选题What is a characteristic of all centrifugal cargo pumps? （）A
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Decreasing the speed of rotation will decrease the discharge pressureC
Opening the discharge valve wider will increase the discharge pressureD
All of the above
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单选题An advantage of a helical gear pump over a simple gear pump is that the helical gear pump is capable of （）.A
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delivering liquids over greater distancesC
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单选题If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.A
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capacity will decreaseC
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suction pressure will decrease
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单选题Most pump manufacturers recommended that the discharge piping for centrifugal pumps be （）.A
one size larger than the pump discharge nozzleB
the same size as the pump discharge nozzleC
one size smaller than the pump discharge nozzleD
installed with a short radius elbow at the pump
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单选题In （） pumps a closed discharge valve will cause bursting discharge pressure.A
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plungerC
injectorD
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单选题Which of the following pumps will build up a bursting pressure or stall their motors if the discharge valves are closed?（） (1) gear (2) centrifugal (3) screwA
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（2）and（3）
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单选题Which of the listed statements is correct concerning the starting of centrifugal pumps?（）A
They should always be started with the discharge valve closedB
They should always be started with the discharge valve openedC
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单选题The （） discharge a nearly constant amount of liquid regardless of pressure.A
mixed-flow pumpB
axial-flow pumpC
centrifugal pumpD
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单选题Gear pumps are （） type because they discharge a near constant amount of liquid regardless of pressure.A
positive displacementB
non-positive displacementC
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axial-flow
考题
单选题Centrifugal pumps are popular because they are very simple in construction,and produce smooth, constant, （） discharge.A
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positiveD
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单选题Fuel oil transfer systems used onboard diesel propelled vessels are required to have （）.A
two fuel oil transfer pumps provided where one is to be independent of the main engineB
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单选题A spur gear pump should be operated with the discharge valves （）.A
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单选题If the discharge valve is closed before the drive motor is stopped, which of the following types of pumps will most likely be damaged?（）A
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GearC
PropellerD
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单选题The responsibilities of the engineer officer in charge of the watch do not include （）A
to ensure the main propulsion plant are kept under constant surveillanceB
to ensure the auxiliary systems are kept under constant surveillanceC
to inspect the steering gear spaces at suitable intervalsD
to inspect and overhaul the equipments in his charge
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