The bypass valve on a self-contained breathing device should be opened if ______．A.You are entering a space containing poisonous vaporsB.You are entering a space containing explosive gasesC.The regulator of the breathing apparatus malfunctionsD.The face piece of the breathing device is too tight
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
相关考题：
On a ship, the locker or space containing the self-contained breathing apparatus must _____.A.be located in close proximity to the main control stationB.be equipped with battery powered emergency lightingC.be marked SELF-CONTAINED BREATHING APPARATUSD.All of the above
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What is the minimum period of time that the air supply for a self-contained breathing apparatus is required to last?________.A.10 minutesB.20 minutesC.30 minutesD.90 minutes
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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 bodyB.allow the wearer to manually give himself oxygenC.release excess heat which would otherwise cause the bottle to explodeD.allow exhaled gases to pass outside the bottle
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单选题The bypass valve on a self-contained breathing device should be opened if（）.Ayou are entering a space containing poisonous vaporsByou are entering a space containing explosive gasesCthe regulator of the breathing apparatus malfunctionsDthe face piece of the breathing device is too tight
单选题Which of the valves listed should be used either in the fully opened or the fully closed position?（）AA gate valveBA globe valveCAny check valveDAny needle valve
单选题Gas masks（）.Ashould be worn while fighting a fireBcan be used in atmospheres deficient in oxygenCfilter contaminants from air that is to be breathedDmay be substituted for a self-contained breathing apparatus
单选题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（）Arack position should be adjustedBcompensating needle valve should be opened fully compensatingCneedle valve should be adjusted to stabilize operationDspeed limiting device should be adjusted
单选题The C02 flooding system is actuated by a sequence of steps which are（）.Abreak glass，pull valve，break glass，pull cylinder controlBsound evacuation alarm，pull handleCopen bypass valve，break glass，pull handleDopen stop valve，open control valve，trip alarm
单选题The rated operating time of a self-contained breathing device may be reduced in actual use because of（）.Apressure differences in the atmosphereBthe length of the hose attached to the facepieceCthe physical exertion of the person wearing the deviceDspaces containing poisonous vapors
单选题Worn diesel engine intake valve guides can result in （）Aincreased engine breathing efficiencyBexcessive valve lashCexcessive lube oil consumptionDlower than normal fuel consumption
单选题If the head pressure of a reciprocating refrigeration compressor is excessive, （）.Athe relief valve should open before the high pressure cutoutBthe relief valve should open and allow the excess refrigerant to flow to the receiverCthe high pressure cutout switch should operate before the relief valve opensDyou should close in on the suction valve
单选题A gate valve installed in a pipeline should be （）.Aused in either the fully dosed or fully opened positionBinstalled with the stem downCused for steam service onlyDused to throttle or regulate the flow of liquid
单选题The function of the bypass valve on the self-contained breathing apparatus is to（）.Acontrol the pressure of the oxygen as it enters the bodyBallow the wearer to manually give himself oxygenCrelease excess heat which would otherwise cause the bottle to explodeDallow exhaled gases to pass outside the bottle
单选题Once a fire is detected the engine should be slowed downOn no account （）.Athe trunking should be opened upBshould the trunking be opened upCthe trunking should not be opened upDshould the trunking not be opened up
单选题The self-contained breathing device should not be used in which situation?（）AOxygen deficient spacesBCompartments containing poisonous vaporsCFighting fires that produce heavy smokeDUnderwater search
单选题Which emergency equipment should you keep near the towing bitts（）.AA self-contained breathing apparatusBA boat hook and a spanner wrenchCA fire ax and/or cutting torchDA Stokes litter basket
单选题The exhaust valve is opened at about the same time （） the air inlet ports are opened.AbeforeBafterCwhenDuntil
单选题Which emergency equipment should you keep near the towing bitts? （）AA self-contained breathing apparatus (SCBA)BA boat hook and a spanner wrenchCA fire ax and/or cutting torchDA Stokes litter basket
单选题You are about to enter a compartment to investigate a suspected smoldering fireIf youre not wearing a self-contained breathing apparatus, you should test the compartments atmosphere to determine if there is/are （）.Asufficient oxygen to sustain human lifeBan explosive mixture in the compartmentCa toxic atmosphere in the compartmentDAll of the above
单选题The basic training in fire prevention and fire fighting should include the practical elements which should allow the trainees to acquire the ability to （）.Ause self-contained breathing apparatusBuse various types of portable fire extinguishersCeffect a rescue in a smoke-filled space wearing breathing apparatusDAll of the above
单选题In slow speed two-stroke engines,（）the fresh air entering begins when and stops as（）Athe inlet port is opened by the up coming piston； the port is closed by the down goingBthe inlet valve is opened by the down going piston；the inlet valve is closedCthe inlet port is opened by the down going piston；the port is closed by the up comingDthe inlet valve is opened
单选题A ship must have a self-contained breathing apparatus to be used as protection from gas leaking from a refrigeration unit. To meet this requirement，you may use（）.Aa gas mask certified by the Mine Safety and Health AdministrationBthe same self-contained breathing apparatus required with the fireman's outfitCan oxygen breathing apparatus，provided that the device has been inspected within three yearsDa portable ventilation system that will provide a complete change of air every three minutes