If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.

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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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• In setting the valves on a steam-smothering system on a tank vessel，the master control valve to cargo tanks should be（）.

  A . open and individual tank valves open B . open and the individual tank valves closed C . closed and the individual tank valves closed D . closed and the individual tank valves ope

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• Safety valves on a boiler vent to the （）.

  A . fuel tank B . bilge C . atmosphere D . auxiliary exhaust line

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• The needle valve will open when the fuel pressure acting on the needle valve （） exerts a sufficient force to overcome the spring compression.

  A . tape face B . tapered face C . surface D . thinner face

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• If you were inspecting the valve springs on an auxiliary diesel engine, your best indication of impending spring failure would be （）

  A . a glazed surface on the spring B . nicks in the protective coating C . a build up of sludge deposits D . cracks in the surface of the spring

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• The expansion valve on a Freon system controls the （）.

  A . superheat of the gas leaving the compressor B . back pressure in the evaporator C . temperature of the icebox D . superheat of the gas leaving the evaporator

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• If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.

  A . increase the capacity of the coil B . increase the superheat at the bulb C . deliver more refrigerant to the coil D . decrease the capacity of the coil

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• In setting the valves on a steam-smothering system on a tanker，the master control valve to cargo tanks should be（）.

  A . open and individual tank valves open B . open and the individual tank valves closed C . closed and the individual tank valves closed D . closed and the individual tank valves ope

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• The bypass valve on a self-contained breathing device should be opened if（）.

  A . you are entering a space containing poisonous vapors B . you are entering a space containing explosive gases C . the regulator of the breathing apparatus malfunctions D . the face piece of the breathing device is too tight

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• In a full flow type lube oil system, the bypass relief valve will lift due to （）

  A . a clogged filter element B . excessive lube oil pump discharge pressure C . excessive lube oil flow D . excessively hot lube oil

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• If the needle valve in a fuel injection nozzle sticks open （）.

  A . no fuel will be delivered through the nozzle B . the nozzle will overheat and crack C . time of injection will change D . fuel will leak into the drain line

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• A large valve，usually installed above the ram preventers，that forms a seal in the annular space between the pipe and wellbore or，if no pipe is present，on the wellbore itself is called the（）.

  A . annular blowout preventer B . annulus C . accumulator D . automatic choke

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• The needle valve in a fuel valve will （） when the fuel pressure action on the needle valve tapered face exerts a force lower than that of the spring compression.

  A . be jammed B . be opened C . be seated D . be broke

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• Which one of following statement is not true concerning the suitable sites of the direct acting relief valve and the pilot operated relieve valve?（）

  A . the direct acting relief valve is used for controlling lower flows and pressure B . the pilot operated relief valve is used for controlling higher flows and pressure C . the pilot operated relief valve is used for controlling lower flows and pressure D . the controlling accuracy of direct acting relief valve is worse than that of the pilot operated relief valve

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• If a single cylinder relief valve on a diesel engine lists frequently while the engine is running, the cause may be an （）

  A . excessively late injection timing for each cylinder B . incorrectly adjusted intake valve timing C . incorrectly adjusted fuel injector D . incorrectly adjusted intake valve clearance

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• What is the purpose of pressure-vacuum relief valves? （）

  A . Regulation of discharge pressure from cargo pumps B . Maintaining constant velocity in cargo lines C . Regulation of suction head on cargo pumps D . To maintain a tank or void at atmospheric pressure

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• A device fitted over the discharge opening on a relief valve consisting of one or two woven wire fabrics is called a（）.

  A . flame stopper B . flame screen C . flame filter D . flame restrictor

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• Cargo pump relief valves are piped to the（）.

  A . cargo pump pressure gauges B . crossover lines interconnecting two pumps C . suction side of pumps D . atmosphere through pump vent

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• If the relief valve on a diesel engine cylinder lifts, the cause could be due to （）

  A . liquid in the cylinder B . low compression in the cylinder C . high exhaust temperature D . poor fuel penetratio

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• The function of the bypass valve on the self-contained breathing apparatus is to（）.

  A . control the pressure of the oxygen as it enters the body B . allow the wearer to manually give himself oxygen C . release excess heat which would otherwise cause the bottle to explode D . allow exhaled gases to pass outside the bottle

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• The purpose of the safety relief valves installed on an auxiliary boiler is to （）.

  A . relieve excess fuel oil pressure during the “off” fire cycle B . admit water to the dry pipe C . throttle the forced draft fan output for proper combustion D . reduce excess steam pressure in the boiler

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• When the relief valve opens it discharges high pressure refrigerant vapor to the （）.

  A . liquid strainer B . refrigerant inlet of the condenser C . inlet side of the evaporator D . suction side of the compressor

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• On the all-purpose nozzle，the position of the valve when the handle is all the way forward is（）.

  A . shut B . fog C . solid stream D . spray

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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

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