A centrifugal impeller consists of a number of vanes curving （） from the direction of rotation.

相似题目

• Cavitation erosion in the cooling water system of a diesel engine usually occurs at the pump impeller, and on the waterside of the （）

  A . fuel nozzle holders B . exhaust value guides C . engine cylinder liners D . low temperature and a low viscosity

  查看最佳答案

• 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

• 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

  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

• A multistage centrifugal pump can be BEST described as having （）.

  A . two or more impellers housed together in one casing and mounted on a single shaft B . a single stepped impeller mounted in a progressively staged casing C . a large radial clearance between the impeller and casing to prevent overheating due to D . an increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stage

  查看最佳答案

• 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

  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

• 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

  查看最佳答案

• To absorb the wear resulting from impeller rotation and abrasives in the liquid, a centrifugal pump is usually fitted with （）.

  A . lantern rings B . bearings C . easing volutes D . wearing ring

  查看最佳答案

• 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

  查看最佳答案

• On board supply vessels, a centrifuge is normally used to purify（）

  A . cooling water B . fuel oil C . sea water D . diesel intake air

  查看最佳答案

• The basic function of the centrifugal pump impeller is to （）.

  A . directly increase the pressure of the liquid being pumped B . directly increase the velocity of the liquid being pumped C . convert the potential energy of the liquid to kinetic energy D . separate air from the liquid being pumped

  查看最佳答案

• 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 balance

  查看最佳答案

• What is a characteristic of all centrifugal cargo pumps? （）

  A . They are self-priming B . Decreasing the speed of rotation will decrease the discharge pressure C . Opening the discharge valve wider will increase the discharge pressure D . All of the above

  查看最佳答案

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

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

  查看最佳答案

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

  A . priming water B . power supply C . packing gland D . bearing lubricatio

  查看最佳答案

• 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

  查看最佳答案

• A centrifugal compressor’s purge recovery unit（）

  A . reclaims water B . purges air without losing refrigerant C . purges air with some loss of refrigerant D . purges lube oil from the refrigerant

  查看最佳答案

• To operate a centrifugal fire pump at reduced capacity, you should （）.

  A . readjust the relief valve B . throttle the suction line C . throttle the discharge valve D . open the priming line

  查看最佳答案

• High-speed rotation in a centrifugal purifier can produce a force （） the force of gravity.

  A . many thousand times larger than B . the same as C . many thousand times smaller D . none of the above

  查看最佳答案

• Completa las oraciones con la opción adecuada.El sacerdote vivía junto con ___________ en la ciudad de México.

  查看最佳答案

• _ the pros snd cons before making a final decision.

  A、Balanced B、Balance C、Balancing D、Balanction

  查看最佳答案

• A research paper con tains three categories of materials which include_______.

  A.the preliminaries B.the text of the paper C.the reference materials D.all of the above

  查看最佳答案

• El problema de la baja tasa de natalidad en Espa a se ve compensado con:

  A．La población espaola es relativamente joven: el 15% de los espaoles son menores de 14 aos． B．El crecimiento flujo de inmigrantes y su alta tasa de nataliD C．El índice de población con más de 65% aos es relativamente bajo, el 17%． D．El índice de natalidad ha bajado también en cada de U．E

  查看最佳答案