What causes cavitation in a centrifugal pump ________．A.Vapor pockets in the flow streamB.Rough impeller surfacesC.Worn wearing ringsD.Heavy fluid in the flow stream

题目

What causes cavitation in a centrifugal pump ________．

A.Vapor pockets in the flow stream

B.Rough impeller surfaces

C.Worn wearing rings

D.Heavy fluid in the flow stream

相似考题

1.● To determine what causes the majority of quality problems in a process, a very useful tool is the （）.（）A. cause and effect diagrams B. flow chartC. control chart D. pareto chart

2.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

3.All of the following steps are taken in starting a centrifugal pump，EXCEPT to ______．A.Set the relief valveB.Check the lubrication systemC.Vent the pump casingD.Open the pump suction and discharge valves

4.Throttling in the _____ line of a centrifugal pump involves the risk of the pump cavitation.A.suctionB.exhaustC.pressureD.discharge

更多“What causes cavitation in a centrifugal pump ________.A.Vapor pockets in the flow streamB. ”相关问题

  • 第1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

  • 第2题：

    单选题
    With respect to centrifugal pump impellers, which of the following descriptions represents the correct centrifugal pump classification? （）
    A

    Single stage or multistage

    B

    High pressure or low pressure

    C

    Open or close coupled

    D

    Horizontal or vertical


    正确答案： C
    解析： 暂无解析

  • 第3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4题：

    单选题
    Most pump manufacturers recommended that the discharge piping for centrifugal pumps be （）.
    A

    one size larger than the pump discharge nozzle

    B

    the same size as the pump discharge nozzle

    C

    one size smaller than the pump discharge nozzle

    D

    installed with a short radius elbow at the pump


    正确答案： C
    解析： 暂无解析

  • 第5题：

    单选题
    Increasing the speed of a centrifugal pump will result in an increase in its capacity Another means of increasing the capacity of a centrifugal pump is to increase the （）.
    A

    diameter of the discharge piping, with all other factors remaining the same

    B

    diameter of the suction piping, with all other factors remaining the same

    C

    width of the impeller only

    D

    diameter of the impeller


    正确答案： B
    解析： 暂无解析

  • 第6题：

    单选题
    Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to（）
    A

    facilitate bi-directional operation

    B

    provide the greatest pump efficiency

    C

    prevent pump clogging from marine growth

    D

    prevent cavitation at the pump outlet


    正确答案： A
    解析： 暂无解析

  • 第7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8题：

    单选题
    The purpose of the wearing rings used in a centrifugal pump is to （）.
    A

    prevent an internal explosion in the pump when it is overheated

    B

    enable a visual inspection of the pump while it is running

    C

    insure a proper alignment of the pump coupling to the driver

    D

    accommodate for friction between the impeller and the easing


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    The most suitable pump for oily water separator feed duties is （）.
    A

    a reciprocating pump

    B

    a vane pump

    C

    a centrifugal pump

    D

    a triple screw pump


    正确答案： C
    解析： 暂无解析

  • 第10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11题：

    单选题
    A centrifugal pump attempting to develop flow against a closed discharge valve has a/an （）.
    A

    capacity of 0%

    B

    efficiency of 100%

    C

    internal slippage of 0%

    D

    shut off horsepower rating of 100%


    正确答案： C
    解析： 暂无解析

  • 第12题：

    单选题
    Which of the listed conditions can lead to cavitation气穴in a centrifugal pump?（）
    A

    Vapor pockets formed in the suction flow stream

    B

    Rough easing volute surfaces

    C

    Worn wearing rings

    D

    Heavy fluid in the flow stream


    正确答案： D
    解析： 暂无解析

  • 第13题：

    The most serious effect of air trapped in a diesel engine jacket water cooling system is that it ______．

    A.Causes colloid suspension in the cooling water

    B.Reduces the capability of the lubrication system

    C.Can form pockets which block the flow of coolant through the system

    D.Leads to the scuffing of cylinder walls


    正确答案：D

  • 第14题：

    单选题
    Which of the following statements is correct with regards to the operation of a centrifugal cargo pump?（）
    A

    Oil is discharged from the impeller through the outlet

    B

    Gravity causes the oil to flow toward the discharge

    C

    The self-priming feature of the centrifugal pump enables it to draw its own suction as it starts

    D

    The discharge capacity varies directly with the speed of the impeller


    正确答案： C
    解析： 暂无解析

  • 第15题：

    单选题
    Which one is not the component of a typical, marine pattern self-contained unit?（）
    A

    a centrifugal fan

    B

    a direct expansion cooler

    C

    a hermetic compressor

    D

    a centrifugal pump


    正确答案： D
    解析： 暂无解析

  • 第16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17题：

    单选题
    All of the following steps are taken in starting a centrifugal pump，EXCEPT to（）.
    A

    set the relief valve

    B

    check the lubrication system

    C

    vent the pump casing

    D

    open the pump suction and discharge valves


    正确答案： C
    解析： 暂无解析

  • 第18题：

    单选题
    The usual symptoms of cavitation in a centrifugal pump is （）.
    A

    noise and vibration

    B

    an increase in discharge pressure

    C

    an increase in suction pressure

    D

    lifting of the relief valve


    正确答案： B
    解析： 暂无解析

  • 第19题：

    单选题
    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


    正确答案： D
    解析： 暂无解析

  • 第20题：

    单选题
    Which pump is the self-priming pump?（）
    A

    turbine

    B

    centrifugal

    C

    ejector

    D

    mixed flow


    正确答案： B
    解析： 暂无解析

  • 第21题：

    单选题
    Most pump manufacturers recommend that the suction piping dimension for centrifugal pumps be （）.
    A

    one size smaller than the pump suction nozzle

    B

    the same size as the pump suction nozzle

    C

    one size larger than the pump suction nozzle

    D

    installed with a short radius elbow at the pump


    正确答案： B
    解析： 暂无解析

  • 第22题：

    单选题
    A centrifugal pump produces flow with a resulting discharge head by energy conversionIt is typical for the energy conversion to follow the order of （）.
    A

    mechanical energy to kinetic energy to potential energy

    B

    mechanical energy to potential energy to kinetic energy

    C

    potential energy to mechanical energy to kinetic energy

    D

    kinetic energy to mechanical energy to potential energy


    正确答案： A
    解析： 暂无解析

  • 第23题：

    单选题
    On modern ships, centrifugal pump with a self-primer has replaced reciprocating pump as bilge pump because（）
    A

    centrifugal pump is cheaper than reciprocating pump

    B

    the size of centrifugal pump with same capacity is smaller than that of reciprocating pump

    C

    centrifugal pump makes maintenance easier than reciprocating pump does

    D

    all of the above


    正确答案： B
    解析： 暂无解析

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