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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
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If the compensating needle valve of a hydraulic governor is opened more than necessary the governor will （）
A . have a larger than normal dead band
B . produce excessive speed response to a load change
C . respond slowly to any change in engine load
D . stabilize engine speed at the new governor setting
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A variable displacement system of hydraulic drives consists of （）.
A . a variable displacement axial piston pump
B . a constant displacement axial piston pump
C . a reciprocating piston pump
D . a centrifugal pum
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Which of the following types of hydraulic pumps would be used in a steering system?（）
A . Lobe
B . Screw
C . Radial piston
D . Volute
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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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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
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If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
A . add fluid that is the same color as the fluid in the reservoir
B . add turbine oil because it is always a good substitute
C . add any oil that has the same viscosity as the hydraulic fluid
D . check the winch manufacturers instruction book
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If a diesel engine has been stopped because of piston seizure due to severe overheating, the crankcase（）
A . inspection covers should not be opened until the engine has cooled
B . ventilation system should be continued in operation for one hour for cooling
C . scavenge pump should be immediately secured to prevent loss of lube oil
D . explosion covers should be opened slightly to provide extra ventilatio
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Pitted reduction gear teeth having a deep blue color with evidence of overheating have been operated with （）
A . excessive speed
B . improper warm-up
C . extreme misalignment
D . inadequate lubricatio
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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
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When a hydraulic vane pump is working, which of the following is in contact with the vanes?（） (1) the rotor (2) the internal surface of the housing (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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Which of the listed pressure control valves would be used to establish the maximum operating pressure of a hydraulic system?（）
A . Pressure-reducing valve
B . Unloading valve
C . Counterbalance valve
D . Pressure-relief valve
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Sluggish response or action of the hydraulic actuators may be a result of （）.
A . insufficient load
B . excessively high oil viscosity
C . relief-valve pressure setting too high
D . reservoir level being maintained two inches above normal
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If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
A . a low load on the unit
B . a clogged pump suction strainer
C . a blockage in the line between the pump and hydraulic motor
D . the hydraulic motor turning too fast
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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
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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
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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
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As for a hydraulic single action vane pump, the inner wall of the stator is usually of （） shape.
A . circular
B . elliptical
C . rectangular
D . hexago
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You should frequently compare drum-mounted and remote-reading water level indicators（） between these have contributed to failures because of overheating through shortage of water, when a boiler was being oil-fired.
A . descriptions
B . discrepancies
C . different
D . deflectio
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The rotor of the hydraulic motor rotates at a speed proportional to the （）.
A、flow of oil
B、pressure of oil
C、flow and pressure of oil
D、temperature of oil
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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
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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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If the pump for a hydraulic anchor windlass is overheating, the cause may be （）.
A . excessive drive motor speed
B . excessive pump discharge pressure
C . too low of a tilting box angle
D . insufficient drive motor speed
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When the relief valve is used as a constant pressure valve, it is connected to the outlet of the hydraulic pump to ensure that the outlet pressure of the hydraulic system (pump) is constant.
A:正确;
B:错误
