更多"Valve overlap is the period during "的相关试题:
[单项选择]During the valve overlap period, the exhaust pressure of a turbochargers, four-stroke/cycle diesel engine must be less than the intake manifold pressure to ensure （）
A. effective cylinder scavenging and cooling
B. constant pressure from the turbochargers
C. cooler operation of the exhaust system
D. effective constant pressure for turbocharger operation
[单项选择]The period of valve overlap is when （）.
A. the inlet valve is open
B. the exhaust valve is open
C. both valves are close
D. both valves are open
[单项选择]Where a period is fixed during which freight is to be paid，the Shipowner must（）to deliver the goods throughout the whole of that period if he wishes to claim payment.
A. be had
B. be made
C. be prepared
D. be delivered
[单项选择]The valve which is most suited for regulating the flow through a pipeline is a （）
A. gate valve
B. globe valve
C. swing-check valve
D. plug-cock valve
[单项选择]Each cylinder has one starting valve which is usually opened by air pressure and closed by （）
A. nuts and bolts
B. new joints
C. spring force
D. sealing rings
[单项选择]The period at high or low tide during which there is no change in the height of the water is called the （）.
A. range of the tide
B. plane of the tide
C. stand of the tide
D. reversing of the tide
[单项选择]A(n) （） is a special type of valve which prevents the passage of steam but allows condensate to pass.
A. check valve
B. non-return valve
C. steam trap
D. quick closing trap
[单项选择]During working, thermostatic expansion valve should be （）.
A. either all the way open or all the way closed
B. normally fully open
C. throttled depending on load
D. controlled by liquefied pressure
[单项选择]The process during which liquid containing a reasonable amount of sensible heat at a particular pressure immediately changes into steam after admitted to a chamber at a lower pressure is called （）.
A. boiling off
B. flash evaporation
C. condensation
D. none of the above
[单项选择]During which condition should the operator of a pedestal crane shutdown operations?（）
A. Bunkering
B. High winds
C. Potable water spill on deck
[单项选择]During which of the listed piston stroke of a four-stroke/cycle diesel engine, is the piston moving downward?（）
A. Intake stroke
B. Compression stroke
C. Exhaust stroke
D. Pumping stroke
[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]
Leaky exhaust valve will result in which of the following?（）
(1) high exhaust temperature;
(2) low compression pressure;
(3) low firing pressure.
A. (1) and (2)
B. (1) only
C. (2) only
D. (1),(2) and (3)
[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 shut off valve at the gasoline tank which can be operated from outside the tank space （）.
A. controls the amount of gasoline to the engine
B. shuts off the gasoline supply at the tank
C. is used if the gasoline tank leaks
D. All of the above
[单项选择]During a period of whiteout，you should expect which of the following（）.
A. Snowfall or blowing snow
B. Lack of ability to estimate distance
C. Harsh contrast between sun-illuminated snow cover and the background
D. Hazy horizons with extensive mirage effects
