更多"If over a period of weeks the air-b"的相关试题:
[单项选择]The rate of pressure rise during the period following fuel ignition in a diesel will result in （）
A. valve overlap
B. volumetric efficiency
C. turbulence of the air change
D. fuel efficiency
[单项选择]During the fuel injection period, fuel pressure must exceed cylinder gas pressure to （）.
A. ensure penetration and distribution of the fuel in the combustion chamber
B. ensure the needle valve is flushed clean during each injection
C. prevent combustion gas blowback into the open needle valve
D. prevent reflected pressure waves when the needle valve closes
[单项选择]The cooling water temperature （） over a period of 8 hours, and then shut down.
A. should be gradually increased
B. should be gradually reduced
C. should be constantly kept
D. should be varied up and down
[单项选择]If over a period of time, the oi1 film partially disappears, so that dry areas are formed on the cylinder wall, these areas and the piston surfaces will by frictional interaction, become finely scuffed and hardened, iegood mirror surface" will have deterioratedWhat condition of the piston rings can result in this phenomenon?（）
A. micro-seizure
B. sticking
C. scratched
D. breakage/collapse
[单项选择]The fuel oil pressure and forced draught pressure should be matched to ensure good combustion with a full steady flameIn the sentence the word “match” means （）
A. join with
B. mix
C. be equal to
D. be constant
[单项选择]High pressure and low pressure alarms must be tested（）.
A. no earlier than 24 hours prior to loading
B. no later than 24 hours prior to loading
C. anytime prior to loading
D. weekly
[单项选择]The vapor pressure of a gas is the pressure necessary to keep it in a(n)（）.
A. soluble state
B. solid state
C. liquefied state
D. inert state
[单项选择]Rotating flyweights acting against spring pressure make a simple type of （）.
A. governor
B. safety valve
C. reducing valve
D. feed water regulator
[单项选择]The primary reason low pressure evaporators produce distillate more efficiently, and with less scale formation, than high pressure evaporators is （）.
A. evaporation is accomplished in a vacuum
B. due to the higher temperature of the incoming feed
C. due to the latent heat of evaporation principle
D. evaporation in a submerged medium produces more distillate
[单项选择]A more sophisticated pressure reducing valve incorporates a pilot valve which controls the fluid above the valve operating piston in response to downstream pressureThe bold and italic word “which” means （）.
A. a pressure reducing valve
B. a pilot valve
C. an operating piston
D. downstream pressure
[单项选择]The refrigeration system low pressure cutout switch is actuated by （）.
A. an electric system manager
B. a sensing bulb at the tail coil of the evaporator
C. pressure changes in the suction line
D. failure of the king solenoid valve
[单项选择]Thermostatic steam pressure reducing valves are used in the fuel oil service system to control the（）
A. double bottom fuel oil tank temperature
B. heater supply steam flow
C. pressure of the fuel supplied to the burners
D. attemperator steam flow in the heater discharge circuit
[单项选择]An increased pressure differential between the inlet and outlet of a strainer usually indicates the strainer is （）
A. holed
B. fouled
C. clean
D. dry
[单项选择]A substantial increase in crankcase pressure could be an indication of （）
A. excessive lube oil pressure
B. the proper seating of new rings
C. a worn cylinder liner
D. a malfunctioning cylinder relief valve
[单项选择]Reid vapor pressure is（）.
A. exerted by liquid cargo on the sides of a tank
B. exerted by liquid cargo on a cargo hose body
C. the lowest temperature and pressure that will cause a flammable liquid to give off vapors
D. a measurement of the amount of flammable vapors given off by a liquid at a certain temperature
[单项选择]An increase in crankcase pressure generally indicates（）
A. worn connecting rod bearings
B. worn engine cylinder liners
C. high cylinder firing pressure
D. stuck spring-loaded manhole covers
[单项选择]To determine the pressure and temperature limitations under which LFG is required to be transported on a barge，you should look at the（）.
A. Certificate of Inspection
B. loading order
C. rules and regulations for tankers
D. tankerman's document
[单项选择]The diurnal pressure variation is most noticeable in the（）.
A. polar regions
B. horse latitudes
C. roaring forties
D. doldrums
