Through a （） pump, the liquid is transferred from the suction to the discharge by the mechanical variation of the volume of a chamber or chambers.

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• The discharge flow of a reciprocating pump is （）.

  A . steady B . in pulsation C . continuous D . large

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• 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

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• It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong directionThis would cause the pump （）.

  A . head capacity to improve B . discharge to be reversed C . efficiency to decrease D . slippage to decrease

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• As for a hydraulic vane pump, which of the following is in contact with the vanes during working: （） (1)the rotor (2)the pump shaft (3)the external surface of the housing

  A . (1) only B . (2) only C . (1) and (2) D . (1),(2)and(3)

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• 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

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• The pressure head of a pump is given in the unit of （）.

  A . kg B . MPa C . meter fluid column D . None of the above is true

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• The pressure of a liquid leaving the pump can be referred to as the （）.

  A . total head B . discharge head C . net positive suction head D . suction head

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• The fuel injection pumps on a diesel engine are controlled by a linkage system attached to the （）

  A . camshaft B . crankshaft C . governor D . flywheel

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• Which features of a centrifugal pump reduce the need for renewing worn impellers and pump casings?（）

  A . Close radial clearance between impeller hub and casing B . Low rotational speed of impeller C . Removable end plate D . Replaceable impeller and casing wearing ring

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• When starting a reciprocating pump, the inlet valve should be （）.

  A . closed B . opened fully C . cracked open D . partly ope

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• 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)

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• When in operation, it is unavoidable that a small amount of oil （） through leakage, and in order to compensate for these leaks the system is connected to a feed pump.

  A . escapes B . overheats C . expands D . accelerate

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• Movement of the pump control rack in a fuel injection system using individual plunger-type pumps （）

  A . changes the position of the fuel inlet ports B . changes the length of the pump stroke C . varies the quantity of fuel delivered D . varies the compression of the delivery valve spring

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• The oil is drawn from a drain tank through （）, one of a pair of pumps, into one of fine filters.

  A . a strain tank B . a head tank C . a service tank D . a strainer

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• The injector pump is operated by a cam which drives the plunger （）.

  A . top and bottom B . to and fro C . up and down D . back and forth

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• The fire pumps must be capable of delivering a total quantity of water at a defined head, not less than （） of the total bilge pumping capacity.

  A . one-third B . two-thirds C . one-fourth D . two-fourth

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• When starting a centrifugal pump, the discharge valve should be （）.

  A . closed B . opened fully C . cracked open D . partly ope

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• The cleaned heated oil, after passing through the centrifuges, is to be pumped to a （）.

  A . settling tank B . service tank C . ballast tank D . drain tank

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• A pump is said to have "negative suction head" when the pump is located （）.

  A . between the suction and discharge B . below the liquid supply C . above the liquid supply D . any of the above

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• The pressure head of a water pump is given in the unit of （）.

  A . kg B . MPa C . mH20 D . None of the above

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• If a hydraulic pump is overheating, the cause may be （）.

  A、excessive internal leakage in the pump B、low discharge pressure and fluid flow C、excessive fluid level in the hydraulic reservoir D、operation of the pump at 100% efficiency

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• Which of the following pumps are self-priming, and can deal with liquid from a level below the pump（） (1) ejector (2) screw (3) centrifugal

  A . (1)only B . (1)and(2) C . (1),(2)and(3) D . (2)and(3)

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• When the tilting box of a variable stroke axial-piston pump is perpendicular to the pump shaft, which of the following conditions will exist?（）

  A . The pistons reciprocate B . The ‘B’ end cylinder barrel rotates C . There is no fluid flow D . Power is transmitted hydraulically

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• The static suction lift of a pump is the difference in elevation between the （）.

  A . centerline of the pump and the level of the liquid in the suction well when the source of liquid is below the pump B . centerline of the pump and the suction liquid level when the source of liquid is above the pump C . centerline of the pump and the level of the discharge liquid D . liquid levels of the suction and discharge

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