Centrifugal pumps have what advantage（s）over reciprocating pumps ________．A.They are less expensiveB.They are smaller for equivalent pumping abilityC.They pump more cargo in less timeD.All of the above

题目

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

相似考题

1.What is the function of wearing rings found on some centrifugal pumps ________．A.Absorb erosion of high velocity discharge streamB.Seal pump shaft against entry of airC.Isolate the outlet side from the inlet sideD.Dampen the turbulent discharge flow

2.What is an advantage of a gate valve over a butterfly valve ________．A.Less frequent maintenanceB.Faster operationC.CheaperD.More compact

3.What is an advantage of diesel over steam turbine propulsion ________．A.Less fuel consumption per SHPB.Diesel fuel costs less than bunker C or its equivalentC.Less routine maintenance requiredD.Less weight per SHP

4.What is a requirement for remote manual shutdown stations for internal combustion engine driven cargo pumps on tank barges ________．A.They must be conspicuously markedB.They must be located at least 10 feet from the engineC.There must be at least two such shutdown devicesD.The valve rods shall be fitted with stuffing boxes

参考答案和解析
正确答案：D
更多“Centrifugal pumps have what advantage(s)over reciprocating pumps ________.A.They are less ”相关问题

  • 第1题：

    单选题
    Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are （）.
    A

    operated manually once an hour

    B

    operated until the engine has started

    C

    placed into operation only at maximum load

    D

    adjustable to meet lubrication requirements


    正确答案： B
    解析： 暂无解析

  • 第2题：

    单选题
    Which of the following statements represents the advantage of rotary pumps as compared to reciprocating pumps?（）
    A

    The high discharge pressure of the rotary pumps permits a larger volume of fluid per unit time than the reciprocating pump

    B

    Rotary pumps are capable of pumping more fluid than reciprocating pumps of the same weight

    C

    Rotary pumps occupy only one-half the space of reciprocating pumps

    D

    Rotary pumps eliminate discharge slippage of the pumped liquid, while this does not hold true for a reciprocating pump


    正确答案： B
    解析： 暂无解析

  • 第3题：

    单选题
    The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.
    A

    gear

    B

    nonpositive displacement

    C

    positive displacement

    D

    rotary


    正确答案： A
    解析： 暂无解析

  • 第4题：

    单选题
    What is a characteristic of all centrifugal cargo pumps? （）
    A

    They are self-priming

    B

    Decreasing the speed of rotation will decrease the discharge pressure

    C

    Opening the discharge valve wider will increase the discharge pressure

    D

    All of the above


    正确答案： C
    解析： 暂无解析

  • 第5题：

    单选题
    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


    正确答案： D
    解析： 暂无解析

  • 第6题：

    单选题
    Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.
    A

    reciprocating

    B

    hydraulic

    C

    turbine

    D

    vane


    正确答案： D
    解析： 暂无解析

  • 第7题：

    单选题
    Lube oil pumps taking suction from the sump of most small marine engines are usually （）.
    A

    of the diaphragm type

    B

    of the centrifugal type

    C

    of the positive displacement type

    D

    independently driven by electric motors


    正确答案： D
    解析： 暂无解析

  • 第8题：

    单选题
    When installed for bilge pumping or ballast duty, centrifugal pumps require a （） to remove air from the suction pipe.
    A

    air chamber

    B

    head lank

    C

    primer

    D

    prime mover


    正确答案： D
    解析： 暂无解析

  • 第9题：

    单选题
    Which of the materials listed is used as the dynamic seal material on mechanical seals installed on most centrifugal pumps used in water service?（）
    A

    Copper

    B

    Copper and carbon

    C

    Carbon

    D

    Bronze


    正确答案： A
    解析： 暂无解析

  • 第10题：

    单选题
    Centrifugal pumps, however, can be designed with a number of impellers （） to attain a large amount of liquid.
    A

    in series

    B

    in parallel

    C

    assembled

    D

    together


    正确答案： C
    解析： 暂无解析

  • 第11题：

    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 engine

    B

    two fuel oil transfer pumps, with a combined capacity exceeding the maximum consumption of the main engine

    C

    engine driven transfer pumps and only used in constant speed applications

    D

    the capacity of the engine driven pump exceed the consumption rate of the engine to which it is attached


    正确答案： D
    解析： 暂无解析

  • 第12题：

    单选题
    What is a function of the wearing rings used in most centrifugal pumps?（）
    A

    Absorb erosion of high velocity discharge stream

    B

    Seal pump shaft against entry of air

    C

    Isolate the discharge side from the suction side

    D

    Dampen the turbulent discharge flow


    正确答案： C
    解析： 暂无解析

  • 第13题：

    单选题
    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）


    正确答案： B
    解析： 暂无解析

  • 第14题：

    单选题
    Air chambers are usually fitted to reciprocating pumps in order to （）.
    A

    increase discharge pressure

    B

    increase suction vacuum

    C

    develop pulsation flow

    D

    keep a steady rate of flow


    正确答案： D
    解析： 暂无解析

  • 第15题：

    单选题
    A reciprocating pump belongs to （） according to its working principle.
    A

    injector pumps

    B

    positive displacement pumps

    C

    centrifugal pump

    D

    centripetal pumps


    正确答案： A
    解析： 暂无解析

  • 第16题：

    单选题
    What is an advantage of diesel over steam turbine propulsion? （）
    A

    Less fuel consumption per SHP

    B

    Diesel fuel costs less than bunker C or its equivalent

    C

    Less routine maintenance required

    D

    Less weight per SHP


    正确答案： C
    解析： 暂无解析

  • 第17题：

    单选题
    机舱人员应启动机舱里的消防泵。（）
    A

    Engine room persons should stop their pumps in machinery space.

    B

    Engine room persons should start their pumps in machinery space.

    C

    Engine room persons should start their pumps in officer’s cabin.

    D

    Engine room persons should start their pumps on boat deck.


    正确答案： B
    解析： 暂无解析

  • 第18题：

    单选题
    The injection may be delayed, （）the pumps are in good order, if the fuel lines to the injection valves have not been cleared of air.
    A

    because

    B

    though

    C

    since

    D

    until


    正确答案： A
    解析： 暂无解析

  • 第19题：

    单选题
    Which of the following pumps belongs to centrifugal pump?（）
    A

    Piston pump

    B

    Screw pump

    C

    Diffuser pump

    D

    Water-ring pump


    正确答案： B
    解析： 暂无解析

  • 第20题：

    单选题
    The advantage of a centrifugal pump as compared with a reciprocating pump is that （）.
    A

    discharge is continuous

    B

    it has no internal valves

    C

    upon accidental closing of discharge valve, excessive pressure will not build up

    D

    all of the above are true


    正确答案： A
    解析： 暂无解析

  • 第21题：

    单选题
    Which of the following statements concerning the lubrication of diesel propulsion engines used in vessels over 300 gross tons is most accurate?（）
    A

    Lubrication systems using engine driven lube oil pumps do not require any additional independent arrangement when such arrangements have been proven reliable

    B

    The use of engine driven pre-lube pumps is permitted on vessels with propulsion systems developing less than 500 shaft horsepower

    C

    When forced lubrication is used for propulsion engines, one independently driven stand-by pumps is to be provided in addition to the necessary pumps for normal operation

    D

    Lubrication systems where two oil coolers are fitted require a minimum of two temperature control devices which may be actuated by similar sensors


    正确答案： A
    解析： 暂无解析

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