单选题If a centrifugal pump vibrates and is noisy when operating, the cause could be （）.A worn gland sealing shaftB worn wearing ringsC a bent shaftD reversed pump coupling

题目
单选题
If a centrifugal pump vibrates and is noisy when operating, the cause could be （）.
A

worn gland sealing shaft

B

worn wearing rings

C

a bent shaft

D

reversed pump coupling

相似考题

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

2.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

3.单选题With respect to centrifugal pump impellers, which of the following descriptions represents the correct centrifugal pump classification? （）A Single stage or multistageB High pressure or low pressureC Open or close coupledD Horizontal or vertical

4.A centrifugal pump may fail to deliver water when first started if the ______.A.water seal pipe is pluggedB.pump is not primedC.seal ring is properly locatedD.impeller is flooded

更多“If a centrifugal pump vibrates and is noisy when operating,”相关问题

  • 第1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2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3题：

    单选题
    Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
    A

    cavitation

    B

    electrolysis

    C

    abrasion

    D

    corrosion


    正确答案： A
    解析： 暂无解析

  • 第4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5题：

    单选题
    The capacity of a centrifugal pump can be increased by the installation of a larger diameter impeller Another means of increasing the pump capacity is to （）.
    A

    increase speed

    B

    increase the size of the cardent assembly

    C

    reduce wearing ring clearances

    D

    change the pump to a close coupled arrangement


    正确答案： A
    解析： 暂无解析

  • 第6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7题：

    单选题
    In order to properly remove air from the casing of a centrifugal pump when starting, the pump should have a （）.
    A

    positive head

    B

    negative suction head

    C

    mechanical seal

    D

    vent valve attached to the casing at the top of the volute


    正确答案： D
    解析： 暂无解析

  • 第8题：

    单选题
    A centrifugal pump may fail to deliver water when first started if the （）.
    A

    water seal pipe is plugged

    B

    pump is not primed

    C

    seal ring is improperly located

    D

    impeller is flooded


    正确答案： A
    解析： 暂无解析

  • 第9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10题：

    单选题
    When starting a centrifugal pump, the discharge valve should be （）.
    A

    closed

    B

    opened fully

    C

    cracked open

    D

    partly open


    正确答案： C
    解析： 暂无解析

  • 第11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

  • 第12题：

    单选题
    Why are removable sleeves installed on centrifugal pump shafts?（）
    A

    They make it easier to replace the pump shaft packing

    B

    They can be economically replaced as they wear out

    C

    They can be removed when it is necessary to lighten the weight of the pump

    D

    They increase the strength of the shaft


    正确答案： A
    解析： 暂无解析

  • 第13题：

    单选题
    The function of a centrifugal pump double volute casing is to （）.
    A

    reduce radial thrust to the impeller

    B

    double the liquid velocity through the pump when compared to a single volute

    C

    reduce hydraulic end thrust

    D

    provide the effect of multi-staging


    正确答案： D
    解析： 暂无解析

  • 第14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15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16题：

    单选题
    When oily water separator is operating, which measure （） is wrong.
    A

    pay attention to operating parameters

    B

    renew and clean separating units in time

    C

    check oil level in separator to prevent overload

    D

    check separating effect, if it is bad, flush with large capacity water pump


    正确答案： A
    解析： 暂无解析

  • 第17题：

    单选题
    If you were operating a centrifugal water service pump with worn wearing rings, the （）.
    A

    pump would be very noisy

    B

    pump would vibrate excessively

    C

    pump would develop insufficient flow

    D

    stuffing box would leak excessively


    正确答案： A
    解析： 暂无解析

  • 第18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19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20题：

    单选题
    Excessive air leakage into the suction side of a centrifugal pump would be indicated by which of the following operational problems?（）
    A

    The pump delivers full capacity when started, but gradually slackens off toan abnormally low flow

    B

    The pump packing gland overheats after short operating periods

    C

    The motor over-current protective device continually shuts the pump down

    D

    Pounding noises can be heard at the pump suction chest


    正确答案： B
    解析： 暂无解析

  • 第21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22题：

    单选题
    The simplest method to use for determining if a centrifugal pump is operating as designed, is to （）.
    A

    closely observe the pump discharge temperature

    B

    close off the discharge valve, and watch for a rise in pressure

    C

    momentarily close off the suction valve, and watch for a rise in pressure

    D

    use a clamp on ammeter and compare the readings to past records


    正确答案： A
    解析： 暂无解析

  • 第23题：

    单选题
    A centrifugal pump vibrates excessively during operationUpon disassembling the pump it is found that the impeller is out of balanceWithout an available spare, you should （）.
    A

    drill holes through the heavy side of the impeller until it balances

    B

    weld counterweights to the light side of the impeller

    C

    remove metal from the heavy side by machining in a lathe

    D

    acid wash and serape the heavy side until it balances


    正确答案： D
    解析： 暂无解析

相关内容