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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
Centrifugal
B
Gear
C
Propeller
D
Turbine
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单选题In （） pump a closed discharge valve will not cause excessive pressure to build up.A
gearB
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单选题What is a characteristic of all centrifugal cargo pumps? （）A
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单选题In （） pumps a closed discharge valve will cause bursting discharge pressure.A
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单选题Why is it important for fuel oil tanks not to be topped off at the inner bottom level when loading on a cold day?（）A
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单选题Which of the listed statements is correct concerning the starting of centrifugal pumps?（）A
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They should always be started with the discharge valve openedC
A priming pump is always required to flood the impeller suctionD
They should always be started with the sealing line valves closed
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单选题A relief valve for a cargo pump is generally installed（）.A
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单选题A centrifugal pump attempting to develop flow against a closed discharge valve has a/an （）.A
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The solenoid valves directs high pressure gas to the underside of the unloading piston, causing it to rise and allowing the recirculating ports to be openedC
When the solenoid valve becomes energized, the valve ports become closed, allowing discharge pressure to build up above the piston, shifting it and causing it to unloadD
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单选题The major difference between the discharge and suction valves installed in most low pressure, reciprocating air compressors is that（）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
CentrifugalB
GearC
PropellerD
Turbine
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单选题In slow speed two-stroke engines,（）the fresh air entering begins when and stops as（）A
the inlet port is opened by the up coming piston； the port is closed by the down goingB
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the inlet valve is opened
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单选题The valve on the discharge side of a cargo pump on a tank vessel will usually be a（）.A
butterfly valveB
spectacle valveC
check valveD
globe valve
考题
单选题If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.A
a low load on the unitB
a clogged pump suction strainerC
a blockage in the line between the pump and hydraulic motorD
the hydraulic motor turning too fast
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