更多"Flame screens are used to（）."的相关试题:
[单项选择]Flame screens are used to（）.
A. contain flammable fumes
B. protect firefighters from flames
C. prevent flames from entering tanks
D. keep flames and sparks from getting out of an engine's exhanst system
[单项选择]A flame screen（）.
A. permits the passage of vapor but not of flame
B. prevents the passage of flammable vapors
C. prevents inert gas from leaving a tank
D. permits vapors to exit but not enter a tank
[单项选择]Flame failure in an automatically fired auxiliary boiler can from a/an （）
A. incorrect electrode setting
B. incorrect nozzle position
C. clogged fuel nozzle
D. broken high tension lead
[单项选择]Backfire flame arrestors are installed on（）.
A. fuel tanks
B. spark plugs
C. carburetors
D. distributors
[单项选择]The flame safeguard control system of a large automatic auxiliary boiler will provide fuel shut off in the case of high （）.
A. water
B. voltage
C. fuel pressure
D. steam pressure
[单项选择]When there is a flame failure in an automatically fired auxiliary boiler, the （）.
A. air supply is shut off
B. fuel supply is shut off
C. water supply is shut off
D. safety valve lifts
[单项选择]A dazzling white burner flame in the boiler furnace indicates （）.
A. proper combustion
B. water in the fuel
C. excess air
D. cold fuel oil
[单项选择]A smoking burner with a pulsating flame in auxiliary boiler, is an indication that the（）
A. fuel oil supply temperature is normal
B. burner electrode is incorrectly positioned
C. fuel／air ratio is incorrect
D. ignition current is too low
[单项选择]Failure of the burner flame in an auxiliary boiler would probably be a result of（）
A. water in the fuel oil
B. broken high tension leads
C. incorrect electrode setting
D. full fuel pressure at the nozzle
[单项选择]If the flame from combustion in the cylinder of a four-stroke engine past the piston into the space below, the accumulation of flammable mixture would be ignited, thus resulting in （）.
A. the crankcase explosion
B. lifting of the cylinder safety valve
C. a scavenge fire
D. opening of the manhole
[单项选择]When subjected to high heat from a open flame, or an electric heating element, which of the listed refrigerants will break down and produce phosgene gas?（）
A. CO2
B. Methyl chloride
C. R-22
D. Sulphur dioxide
[单项选择]The color of the flame on a halide torch without any refrigerant present is （）.
A. blue
B. green
C. orange
D. purple
[单项选择]In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decomposes and from （）
A. petroleum crystals
B. phosgene gas
C. water vapor
D. carbon monoxide
[单项选择]In the event of a flame failure in an auxiliary water-tube boiler, you must（）
A. relight the boiler immediately to prevent loss of steam pressure
B. relight the fire off the brickwork as the bricks are cherry red
C. purge the furnace of any combustible gases before attempting to relight the fire
D. speed up the feed pump to prevent dry firing when the burner flame is reestablished
