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

题目

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 properly located

D.impeller is flooded

相似考题

1.When started, a complete oily water separating unit is first filled ______. The oily water mixture is then pumped through the inlet pipe into the coarse separating compartment.A.with dirty waterB.with clean waterC.by oily waterD.by mixed water

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.What prevents water running along the shaft of a leaking centrifugal pump from entering the shaft bearing ________．A.Shaft sealB.Water flingerC.Drain holeD.Lantern ring

4.If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.A.high steam pressure in the boilerB.abnormally high feed-water temperatureC.abnormally high boiler water temperatureD.steam demand exceeding feed pump capacity

更多“A centrifugal pump may fail to deliver water when first started if the ______.A.water seal ”相关问题

  • 第1题：

    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


    正确答案： C
    解析： 暂无解析

  • 第2题：

    单选题
    A water pump can not supply water after startingIt may be caused by （）.
    A

    closed discharge valve

    B

    broken pipe line

    C

    worn shaft

    D

    both A and B


    正确答案： D
    解析： 暂无解析

  • 第3题：

    单选题
    The main propulsion diesel engine jacket water temperature rises above normal, with the raw water sea suction and the expansion tank water level being normalWhich of the following problems is most likely the cause?（）
    A

    Faulty thermostatic bypass valve

    B

    Eroded zinc pencils in the heat exchanger

    C

    Steam formation in the expansion tank

    D

    Excessive leakage from jacket water pump seal


    正确答案： C
    解析： 暂无解析

  • 第4题：

    单选题
    Before attempting to put out a class “C” fire involving an electric-driven centrifugal pump, you should FIRST （）.
    A

    insulate your shoes

    B

    ground the fire hose

    C

    secure its power supply

    D

    start the fire pump


    正确答案： D
    解析： 暂无解析

  • 第5题：

    单选题
    （）is used in typical marine pattern self-contained unit.
    A

    a water cooled condenser

    B

    a slop tank

    C

    a expansion tank

    D

    a centrifugal pump


    正确答案： B
    解析： 暂无解析

  • 第6题：

    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 closed

    B

    They should always be started with the discharge valve opened

    C

    A priming pump is always required to flood the impeller suction

    D

    They should always be started with the sealing line valves closed


    正确答案： D
    解析： 暂无解析

  • 第7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8题：

    单选题
    When started, a complete oily water separating unit is first filled （）The oily water mixture is then pumped through the inlet pipe into the coarse separating compartment.
    A

    with dirty water

    B

    with clean water

    C

    by oily water

    D

    by mixed water


    正确答案： C
    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
    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
    Water accumulation in the cylinder of a secured engine is an indication that the （）
    A

    soft water pump was not secured along with the engine

    B

    jacket water thermostat has failed

    C

    cylinder liner may be cracked

    D

    raw water pump is over-speeding just prior to engine shutdown


    正确答案： B
    解析： 暂无解析

  • 第12题：

    单选题
    A centrifugal pump can’t supply water after startingYou should check （）.
    A

    priming water

    B

    power supply

    C

    packing gland

    D

    bearing lubrication


    正确答案： C
    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
    A centrifugal bilge pump requires priming （）.
    A

    primarily to lubricate the shaft seals

    B

    due to the inability of this type of pump to lift water to cover the suction (eye) of the impeller

    C

    to initially unload the pump by having its head pressure equal to discharge pressure

    D

    in order to overcome the potential energy of water in the discharge line


    正确答案： D
    解析： 暂无解析

  • 第15题：

    单选题
    Domestic water pump is started automatically by （） which operates as the water level falls to a predetermined level.
    A

    a level controller

    B

    a temperature switch

    C

    a pressure switch

    D

    a floating ball


    正确答案： D
    解析： 暂无解析

  • 第16题：

    单选题
    One of the main functions of wearing rings, as used in a centrifugal pump, is to （）.
    A

    maintain radial alignment between the pump impeller and casing

    B

    absorb all impeller shaft end thrust

    C

    prevent water leakage to the atmosphere

    D

    prevent wear of the pump casing and/or impeller


    正确答案： D
    解析： 暂无解析

  • 第17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18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19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
    To thoroughly pump out the bilges using a horizontally mounted centrifugal pump, the （）.
    A

    pump must always be primed

    B

    volute must impart a radial and rotary motion of the water suction side

    C

    connection must guide the liquid to the lantern rings

    D

    stuffing box should not be allowed any water leakage


    正确答案： D
    解析： 暂无解析

  • 第22题：

    单选题
    The separating effect of oil separator is not very good, the reason may be（）
    A

    too little seal water

    B

    improper gravity disc

    C

    oil discharging pump not working very well

    D

    low water level of the working water


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.
    A

    high steam pressure in the boiler

    B

    abnormally high feed water temperature

    C

    abnormally high boiler water temperature

    D

    steam demand exceeding feed pump capacity


    正确答案： C
    解析： 暂无解析

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