Air bubbles in a hydraulic governor can cause （）

相似题目

• Which of the following statements describes the functions of a reservoir used in a hydraulic system?（）

  A . Dissipate heat B . Trap foreign matter C . Separate air from the oil D . All of the above

  查看最佳答案

• Which of the following types of hydraulic pumps would be used in a steering system?（）

  A . Lobe B . Screw C . Radial piston D . Volute

  查看最佳答案

• Air trapped in the hydraulic fluid of a steering system may be indicated by（）

  A . the steering pumps overspeeding B . a jammed open relief vale C . a constantly occurring improper rudder response D . excessive ram pressure

  查看最佳答案

• After installing a new hydraulic pump in a system, what special attention should be given to the hydraulic system?（）

  A . The relief valves in the system should be readjusted B . The filters and strainers should be checked frequently C . All system pressure should be readjusted D . The system should be drained and renewed with a fluid of different operating characteristic

  查看最佳答案

• The purging of air from an elector-hydraulic steering gear unit is necessary when（）

  A . changing over to hand pump operation B . engaging the trick wheel C . the system has been filled with new oil D . the rudder angle indicator does not match the helm positio

  查看最佳答案

• The basic process of biological sewage treatment consists of the liquor either by bubbling air through it or by agitating the surface（）

  A、oxygenating B、oxidizing C、deoxygenating D、proportioning

  查看最佳答案

• In a fixed displacement axial piston hydraulic motor, the speed is varied by（）

  A、regulating the ratio between torque and speed via the torque limiter at the motor B、directing the motor output flow through a bypass line C、maintaining a constant flow and pressure input D、controlling the input flow rate

  查看最佳答案

• An orifice-check valve placed in a hydraulic system is used to（）

  A . regulate the fluid flow in either direction B . restrict movement of hydraulic fluid in one direction, but allow free movement in the other direction C . allow free movement of hydraulic fluid in both directions D . allow a restricted fluid flow in one direction only

  查看最佳答案

• Air trapped in the hydraulic fluid of a steering system would be indicated by（）

  A . an improper rudder response B . hammering noises in the equipment or transmission lines C . popping or sputtering noises D . all the above

  查看最佳答案

• A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.

  A . the four-way control valve failing to shift B . the bleeder valve sticking in the open position C . cold hydraulic fluid D . a clogged air vent falter on the oil reservoir

  查看最佳答案

• The purpose of the compensating adjustment used in a diesel engine hydraulic governor is to （）

  A . compensate for low oil level B . increase governor promptness C . prevent governor hunting D . limit engine load

  查看最佳答案

• If a hydraulic governor has been refilled with oil, the engine should be operated until it reaches normal temperaturethen the air should be purged, and the（）

  A . rack position should be adjusted B . compensating needle valve should be opened fully compensating C . needle valve should be adjusted to stabilize operation D . speed limiting device should be adjusted

  查看最佳答案

• The major cause of trouble in a mechanical-hydraulic governor is contamination of the hydraulic fluid by （）

  A . dirt B . fuel oil C . governor cooling water D . fuel oil tar

  查看最佳答案

• A liquid sight flow indicator in a refrigeration system is examined and gas bubbles are noted in motion with the fluid flowThis means （）.

  A . the system is fully charged B . there is air leaking in from the condenser C . ice crystals are forming in the refrigerant D . the system contains less than a full charge of refrigerant

  查看最佳答案

• The presence of bubbles in a refrigeration system liquid line may （）.

  A . promote refrigerant dehydration B . be absorbed in the receiver C . cause low condensing pressure D . carry moisture and lead to corrosio

  查看最佳答案

• A large change in ambient temperature, or using an oil of a viscosity different from the one recommended by the manufacturer in a mechanical hydraulic governor, will result in the need to adjust the （）.

  A . pilot valve opening B . compensating needle valve C . compensating spring tension D . accumulator spring tensio

  查看最佳答案

• When normal operating pressure is applied to the hydraulic oil used in a high-pressure system, the oil （）.

  A . viscosity will decrease B . volume will increase C . volume will decrease D . pour point will be reduced

  查看最佳答案

• Which of the problems listed could be indicated if a sight glass in the refrigerant liquid line is full of bubbles?（）

  A . Proper refrigerant charge B . Faulty expansion valve C . Insufficient refrigerant D . Solenoid valve stuck ope

  查看最佳答案

• The extended aeration process consists of （） the liquor either by bubbling air through it or by agitating the surface.

  A . A.deoxygenating B . B.oxygenating C . C.chemicalizing D . D.disinfecting

  查看最佳答案

• Adjustments to the compensating needle valve in a hydraulic governor should be made with the engine at （）

  A . maximum power at a normal load B . maximum power and load under normal conditions C . half speed and normal temperature D . normal operating temperature without a load

  查看最佳答案

• When air becomes trapped in the hydraulic fluid of a steering system, the （）.

  A . rudder will respond sluggishly B . hydraulic rams will over-speed C . sight glass will show bubbles D . ram relief valves will lift

  查看最佳答案

• If a liquid sight flow indicator in a refrigeration system shows gas bubbles in motion passing inside of the glass, there is （）.

  A . too much refrigerant in the system B . oil entrained in the refrigerant C . less than a full charge of refrigerant in the system D . ice crystals forming in the refrigerant

  查看最佳答案

• Hydraulically, servo-operated, automatic, change over valves, utilized in a two ram hydraulic steering gear, serve to .

  A.allow an alternate main pump to start in the fully loaded condition thus developing immediate full torque B.prevent either main pump from being hydraulically motored when idle by cross pressure flow C.prevent both units from operating simultaneously which could result in doubling the flow of oil and pressure leading to over pressurization of the system D.all of the above

  查看最佳答案

• In international air cargo transportation， a freightforwarder offering a consolidation service will issue its own air waybill.Thisis called（）.

  A．MAWB B．HAWB C．IATA D．TACT

  查看最佳答案