更多"If the diesel fuel vapors present a"的相关试题:
[单项选择]Diesel fuel vapors （）.
A. can not be ignited by a spark unless the vapor is in a confined space
B. are nontoxic in all concentrations
C. can not be ignited by a spark unless they are at their auto-ignition temperature
D. are heavier than air
[单项选择]The vapors given off by heated fuel oil are heavier than air and are（）.
A. odorless
B. explosive
C. nontoxic
D. visible
[单项选择]The vapors given off by heated fuel oil are flammable, explosive, and （）
A. lighter than air
B. heavier than air
C. odorless
D. nontoxic
[单项选择]Which statement is TRUE concerning fuel vapors on a vessel（）.
A. Fuel vapors gather in the lowest portions of the vessel
B. Fuel vapors can only be ignited by an open flame
C. Vent outlets should be located above the level of the carburetor air intake
D. None of the above
[单项选择]Which may ignite fuel vapors?（）
A. Static electricity
B. An open and running motor
C. Loose wiring
D. All of the above
[单项选择]Indirect cooling of fuel injector nozzle holders for diesel engines is accomplished primarily by （）.
A. heat conduction into the injected fuel oil
B. heat conduction into the water jacket wall
C. water circulation through passages in the holder
D. fuel oil circulation through passages in the holder
[单项选择]Fuel injection systems meter fuel, atomize fuel, and （）.
A. create turbulence in the combustion chamber
B. aid in completing cylinder scavenging
C. inject fuel at the proper time
D. minimize fuel penetration into the cylinder
[单项选择]Which statement is TRUE concerning gasoline vapors on board a vessel（）.
A. They are heavier than air and will settle in the lowest part of the vessel
B. They are lighter than air and will settle in the highest part of the vessel
C. They should be vented into the engine to improve combustion
D. They should be vented into the wheelhouse
[单项选择]Hydrocarbon vapors are usually detected by the use of the （）.
A. flame safety lamp
B. combustible gas indicator
C. gasometer
D. oxygen indicator
[单项选择]Fuel oil begins injection into the cylinder of a four-stroke/cycle diesel engine during the （）.
A. intake stroke
B. exhaust stroke
C. power stroke
D. compression stroke
[单项选择]The weight of liquefied petroleum gas vapors as compared to air is（）.
A. variable
B. the same
C. lighter
D. heavier
[单项选择]Each hose used for transferring vapors must（）.
A. have a design burst pressure of at least 25 psig
B. be capable of withstanding at least 2.0 psi vacuum without collapsing or constricting
C. be electrically continuous with a maximum resistance of ten thousand ohms
D. All of the above
[单项选择]Damage to cargo caused by fumes or vapors from liquids，gases，or solids is known as（）.
A. contamination
B. oxidation
C. tainting
D. vaporization
[单项选择]Machinery driving fuel oil transfer and fuel oil service pumps must be fitted with a remote means of stopping the machinery from （）.
A. within the space concerned
B. outside the space concerned
C. the throttle station
D. within the fire room
[单项选择]Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce（）.
A. cold corrosion of the nozzles
B. fuel viscosity for better atomization
C. carbon accumulation on the nozzles
D. fuel detonation in the cylinders
[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]A fuel leak occurs in the high pressure fuel piping between the injection pump and fuel nozzleThis requires immediate repair because of the （）
A. high cost of fuel
B. serious fire hazard
C. possibility of pollution
D. poor combustion which will occur in that cylinder
[单项选择]Air in the fuel lines to the fuel injection nozzles of a diesel will result in （）.
A. lower compression pressures
B. overheating without smoking
C. failure to start
D. a run away without load
