The suction - force principle of operation is a typical characteristic of （）.

相似题目

• 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

  查看最佳答案

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

  A . cavitation B . electrolysis C . abrasion D . corrosio

  查看最佳答案

• The three basic parts of any eductor are the nozzle, the suction chamber, and the （）.

  A . injector B . compressor C . diffuser D . sipho

  查看最佳答案

• 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 motor

  查看最佳答案

• A bilge suction line，in a fishing vessel with more than 16 individuals aboard，must have a strainer with an open area not less than how many times the open area of the suction line?（）

  A . one B . two C . three D . four

  查看最佳答案

• A double suction centrifugal pump impeller has been installed in the reverse direction, and will （）.

  A . have a greater head capacity B . operate with increased impeller efficiency C . discharge through the suction side of the pump casing D . require more power to run the shaft

  查看最佳答案

• The emergency bilge suction valve is typically used （）.

  A . to inject cleaning additives when the bilges are extremely dirty B . when the main condenser becomes fouled, in order to provide additional cooling water circulation C . to connect the rose box to the independent bilge suction D . if the bilges become flooded and they can not be emptied by any other mea

  查看最佳答案

• The emergency bilge suction or bilge （） is used to prevent flooding of the ship.

  A、injection valve B、relief valve C、discharge valve D、inlet filter

  查看最佳答案

• The compressor suction line conveys the refrigerant vapor from （） to （）.

  A . condenser；evaporator B . evaporator；compressor C . compressor；condenser D . None of the above

  查看最佳答案

• The major difference between the discharge and suction valves installed in most low pressure, reciprocating air compressors is that（）

  A、one valve seats upwards, while the other seats downwards B、the reed valves used on the discharge are made substantially thicker and heavier than thesuction valves C、the suction valve springs exert a greater tension than the discharge valve springs D、the discharge valve springs exert a greater tension than the suction valve springs

  查看最佳答案

• 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

  查看最佳答案

• 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 pum

  查看最佳答案

• The four strokes are called suction, compression, expansion and exhaust, but only （） stroke provides the power to drive the ship.

  A . suction B . compression C . expansion D . exhaust

  查看最佳答案

• Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）

  A . Increased suction head pressure B . Decreased feedwater temperature C . Pump recirculating line being open too much D . Excessive feedwater temperature

  查看最佳答案

• When liquid reaches the compressor of a refrigeration system through the suction line, the condition is called （）.

  A . flooding back B . superheating C . overflowing D . recycling

  查看最佳答案

• 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

  查看最佳答案

• If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.

  A . refrigerant overcharge B . overfeeding by the expansion valve C . a restricted suction strainer D . due to short cycling of the compressor

  查看最佳答案

• The emergency bilge suction or bilge injection valve is used to prevent （） of the ship.

  A . proceeding B . overloading C . collision D . flooding

  查看最佳答案

• 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.

  A . positive displacement B . ejector C . centrifugal D . air compressor

  查看最佳答案

• During the suction stroke, the piston is moving （）.

  A . inwards B . outwards C . downwards D . upward

  查看最佳答案

• 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

  查看最佳答案

• The lubricating oil is pumped from the drain tank, very often with （） in the suction line.

  A . a filter B . a strainer C . a magnetic filter D . a fine strainer

  查看最佳答案

• In the suction stroke air is induced into the cylinder （）In the compression stroke the air is compressed.

  A . by an fuel valve B . through an inlet valve C . with an exhaust valve D . from an outlet valve

  查看最佳答案

• Among the four strokes of a four-stroke diesel engine,suction and expansion strokes are the upward strokes.()

  此题为判断题(对，错)。

  查看最佳答案