更多"On small, low pressure, air compres"的相关试题:
[单项选择]Excessively low air pressure occurring in the intercooler of a reciprocating air compressor is caused by（）.
A. leaky discharge valves on the LP cylinder
B. leaky discharge valves on the HP cylinder
C. insufficient intercooler cooling
D. low ambient air pressure
[单项选择]Low pressure air is usually taken through （） or pressure regulators to a low pressure reservoir supplying a ring main through driers.
A. globe valves
B. butterfly valves
C. gate valves
D. reducing valves
[单项选择]To add refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through the （）
A. suction service valve as a vapor
B. suction service valve as a liquid
C. discharge service valve as a vapor
D. charging valve as a liquid
[单项选择]In an air conditioning system, low head pressure associated with a reciprocating compressor can be the result of （）
A. broken valve springs
B. tight drive belts
C. high line voltage
D. air in the system
[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]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]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]A yellow signal floating in the air from a small parachute，about 300 feet above the water，would indicate that a submarine（）.
A. has fired a torpedo during a drill
B. is about to rise to periscope depth
C. is on the bottom in distress
D. is disabled and unable to surface
[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]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]Blow-off of the relief valves of the engines cylinders may be caused by （）.
A. too low lead
B. water in fuel
C. too tight spring
D. leakage
[单项选择]Air receivers installed in starting air systems are to be （）.
A. cylindrical in shape with service connections located at the top and bottom
B. opened and made available for inspection during biannual inspections provided
C. with automatic drain traps for the removal of moisture
D. so installed as to make the drain connections effective under extreme conditions of trim
[单项选择]Air entering an air-cooled refrigeration system is indicated by （）.
A. frosting of the liquid line
B. higher than normal head pressure
C. a clear sight glass
D. abnormally cold reefer boxes
[单项选择]Air line lubricators are used in compressed air systems to lubricate （）.
A. the suction and discharge valves
B. tools and equipment served by compressed air
C. air line reducing valves
D. all of the above
[单项选择]Air conditioning is the process of treating air to control （） its temperature, humidity, cleanliness and distribution to meet the comfort requirements of the occupants of the conditioned space.
A. instantaneous
B. instantaneously
C. simultaneous
D. simultaneously
[单项选择]The quantity of cooled air delivered by an air conditioning unit should （） the sum of the quantity of air re-circulated to the unit and the quantity mechanically exhausted.
A. balance
B. not balance
C. be more than
D. be less than
[单项选择]The air compressor pumps air to the （）.
A. expansion tank
B. combustion chamber
C. air receiver
D. evaporator
