更多"The purpose of the low pressure cut"的相关试题:
[单项选择]High pressure and low pressure alarms must be tested（）.
A. no earlier than 24 hours prior to loading
B. no later than 24 hours prior to loading
C. anytime prior to loading
D. weekly
[单项选择]If the high-pressure switch on the compressor opens and stops the compressor a possible cause could be:（）
A. too much cooling water going through the condenser
B. not enough refrigerant in the system
C. a leak in the evaporator coils
D. no enough cooling water going through the condenser
[单项选择]High cylinder firing pressure, accompanied by low exhaust temperature, can result from （）
A. improper fuel rack positing
B. lengthy exhaust valve duration
C. extend operation at light load
D. excessively early injection timing
[单项选择]What separate the high pressure side from the low pressure side in a refrigeration system?（）
A. Condenser and thermal expansion valve
B. King and solenoid valves
C. Compressor and thermal expansion valve
D. Condenser and solenoid valve
[单项选择]The purpose of the refrigeration system low pressure cutout switch is to （）
A. protect the compressor from liquid flood back
B. protect the compressor from low discharge pressure
C. start and stop the compressor upon system demand
D. start the compressor after a drop in the evaporator pressure
[单项选择]What is the purpose of the limit switch on gravity davits?（）
A. To cut off the power when the davits hit the track safety stops
B. To stop the davits from going too fast
C. To cut off the power when the davits are about 12 inches or more from the track safety stops
D. None of the above
[单项选择]The primary reason low pressure evaporators produce distillate more efficiently, and with less scale formation, than high pressure evaporators is （）.
A. evaporation is accomplished in a vacuum
B. due to the higher temperature of the incoming feed
C. due to the latent heat of evaporation principle
D. evaporation in a submerged medium produces more distillate
[单项选择]The refrigeration system low pressure cutout switch is actuated by （）.
A. an electric system manager
B. a sensing bulb at the tail coil of the evaporator
C. pressure changes in the suction line
D. failure of the king solenoid valve
[单项选择]What is the purpose of pressure-vacuum relief valves? （）
A. Regulation of discharge pressure from cargo pumps
B. Maintaining constant velocity in cargo lines
C. Regulation of suction head on cargo pumps
D. To maintain a tank or void at atmospheric pressure
[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 cylinder compression pressure and a high exhaust temperature may indicate （）
A. early fuel injection timing
B. leaking valves
C. a continuously open scavenge air port
D. low cooling water temperature
[单项选择]Low compressor head pressure in a refrigeration system can be caused by（）.
A. insufficient condenser cooling water
B. excessive condenser cooling water
C. air in the refrigeration system
D. excessive refrigerant in the system
[单项选择]In the Southern Hemisphere winds in a low pressure system rotate in a（）.
A. clockwise direction
B. northeasterly direction
C. northerly direction
D. counterclockwise direction
[单项选择]The circulation around a low pressure center in the Northern Hemisphere is（）.
A. counterclockwise
B. variable
C. clockwise
D. anticyclonic
[单项选择]The sensing line for the low pressure cutout switch to a refrigeration system is located （）.
A. in the chill box
B. before the receiver
C. on the suction side of the compressor
D. on the discharge side of the compressor
[单项选择]A low pressure annular preventer which is used to direct flow of kick fluids away from the rig floor is called a （）.
A. dump valve
B. deflector
C. separator
D. diverter
[单项选择]The low pressure side of a refrigeration system is considered to exist from the （）.
A. expansion valve to the compressor
B. receiver to the expansion coil
C. expansion valve to the evaporator
D. condenser to the expansion valve
[单项选择]A generally circular low pressure area is called a(n)（）.
A. cyclone
B. anticyclone
C. cold front
D. occluded front
[单项选择]Broken valve strips in an operating low pressure, air compressor will cause （）.
A. an immediate crankcase explosion
B. oil contamination in the compressed air
C. a decrease in compressor capacity
D. no immediate loss of the compressed air capacity
