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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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On a ship,a fire pump may be used for other purposes if().
A . the other services are run off a reducing station with a pressure gage
B . a separate fire pump is available for use on the fire main
C . all other services are operated by a manifold near the pump
D . All of the above
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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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Which of the following actions should be taken if during a routine maintenance inspection of a centrifugal pump, localized scoring on a pump shaft sleeve is detected?()
A . Correct the cause of the scoring and repair the sleeve or replace with a new one
B . Reassemble the unit and provide more water leak off for proper lubrication
C . Check for parallel alignment of the sleeve radial faces to the sleeve bores
D . Reassemble the unit and adjust the governor to obtain a slower speed
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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
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In an electro-hydraulic steering gear system, when will the variable displacement pump be placed on stroke?()
A . When the helm is at any angle other than amidships
B . When the six-way valve is opened
C . When the ram relief valves lift
D . When the redder angle is different from the position of the helm
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Each fire pump on a tanker must have a pressure gauge located at().
A . the pump discharge
B . the manifold connection
C . each fire station discharge
D . the pump statio
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If an emergency pump control is used as the emergency shutdown on a tanker,it must().
A . stop the flow of oil at the main deck manifold
B . prevent the oil from leaving the shore facility
C . prevent the oil from siphoning through the pump
D . None of the above
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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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If a hydraulic pump on a winch accidentally stops while hoisting,the load will stay suspended because().
A . a check valve will close that prevents reverse circulation
B . a centrifugal counterweight counteracts the force of gravity
C . the electric pump motor cut out
D . the control lever will move to the stop positio
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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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Before doing any work on a hydraulic system equipped with accumulators, you should()
A . drain the accumulators and purge with oxygen
B . bleed off all stored energy from the accumulators completely
C . charge the accumulators to prevent system energy loss
D . pump the hydraulic fluid into the accumulators to prevent fluid lo
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If one hydraulic pump of an electro-hydraulic steering unit falls, the vessels steering can be initially and best maintained by using the ().
A . trick wheel
B . accumulator
C . standby pump
D . telemotor
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An axial piston, variable stroke pump is used in a vessels hydraulic steering gearUnder pressure, oil continually leaks out from between the valve plate/cylinder barrel and will().
A . cause loss of hydraulic oil from the system
B . result in extreme damage to the pump
C . cause damage to the pump ff not continually drained from the pump casing
D . result in the system high side pressure to substantially drop off
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When there is no movement of the rams on an electro-hydraulic steering gear, the tilting box of the running pump is ().
A . set for maximum torque
B . on the purge and vent stroke
C . in the neutral position
D . rotating backward
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On modern ships, centrifugal pump with a self-primer has replaced reciprocating pump as bilge pump because()
A . centrifugal pump is cheaper than reciprocating pump
B . the size of centrifugal pump with same capacity is smaller than that of reciprocating pump
C . centrifugal pump makes maintenance easier than reciprocating pump does
D . all of the above
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A fire pump may be used for other purposes if().
A . the other services are run off a reducing station with a pressure gage
B . one of the required pumps is kept available for use on the fire main system at all times
C . no relief valves are installed
D . all of the above conditions are met
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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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Fuel injection uses the jet pump system and a Woodward type hydraulic () is used to control engine speed.
A . controller
B . governor
C . instrument
D . apparatu
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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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Each fire pump on a ship must have a pressure gauge located at().
A . the pump discharge
B . the manifold connection
C . each fire station discharge
D . the pump statio
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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