更多"Blow-off of the relief valves of th"的相关试题:
[单项选择]The purpose of the safety relief valves installed on an auxiliary boiler is to （）.
A. relieve excess fuel oil pressure during the “off” fire cycle
B. admit water to the dry pipe
C. throttle the forced draft fan output for proper combustion
D. reduce excess steam pressure in the boiler
[单项选择]Cargo pump relief valves are piped to the（）.
A. cargo pump pressure gauges
B. crossover lines interconnecting two pumps
C. suction side of pumps
D. atmosphere through pump vents
[单项选择]Blow-off of the relief valves of the main cylinders during operation indicates （）.
A. the cylinder cover is cracked
B. the injector holes is clogged
C. the cams are not properly set
D. fuel pump is leaking
[单项选择]Which of the following statements concerning cylinder liner wear is true?（）
A. Liner wear is distributed equally between the upper and lower portions of the cylinder
B. Excessive liner wear causes wear between piston ring and groove
C. Excessive, but uniform liner wear will not cause wear between piston ring and groove
D. Liner wear is normally greatest in the middle of the cylinder
[单项选择]Exhaust gases are generally removed from the cylinders of a two-stroke/cycle diesel engine by（）
A. natural aspiration
B. masked intake valves
C. air cells
D. scavenging air
[单项选择]A sudden drop in compression pressure in one cylinder of a diesel engine can be caused by（）
A. a leaking fuel injector nozzle
B. a clogged air filter
C. excessively early fuel injection
D. malfunctioning valves
[单项选择]Before a marine diesel engine is started the cylinders and pistons must be （）.
A. cooled to appropriate temperature
B. warmed up gradually to appropriate temperature
C. opened up and renewed
D. ground and polished
[单项选择]Proper dispersion of fuel in a diesel engine cylinder is dependent upon the （）
A. injection pressure
B. shape of combustion space
C. turbulence in combustion space
D. all of the above
[单项选择]What causes diesel fuel to be ignited in the cylinder of an operating diesel engine?（）
A. Spark plug
B. Heat of compression
C. Carburetor
D. Glow plug
[单项选择]In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low alloy steels because （）.
A. the beveled edges of the intake valves provide for serf-centering during seating
B. intake valves utilize stellite-coated valve seat inserts which reduce wear
C. the volume of air passing through intake valves is less than the volume of air passing through exhaust valves
D. intake valves are less affected to the corrosive action of exhaust gases
[单项选择]On small, low pressure, air compressors, the cylinders are usually lubricated by the （）.
A. splash method
B. mechanical force feed lubricators
C. detached sump method
D. internal cooling passages in the crankshafts and connecting rods
[单项选择]Main engines as well as auxiliary engines operating on heavy fuel should have continuous on the lubricating oil, either according to the bypass or batch principles（）
A. filtering
B. centrifuging
C. depositing
D. operating
[单项选择]Temperature control valves installed in the jacket cooling water system of a diesel engine modulates the rate of water flow through the （）.
A. cooling water pump
B. nozzle cooling passages
C. cylinder jackets
D. heat exchanger
[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]Thermostatic expansion valves can be adjusted for （）.
A. suction pressure only
B. head pressure only
C. superheat only
D. suction pressure and box temperature
[单项选择]Differential needle valves used in fuel injectors are directly closed by（）
A. cam action
B. spring force
C. fuel oil pressure
D. firing pressure
