更多"What function is provided by the cr"的相关试题:
[单项选择]One function provided by a hydraulic accumulator is to（）
A. provide an area where air can separate from the oil
B. provide an area to separate solid contaminants from the oil
C. act as an oil and water separator
D. absorb shocks occurring in the system
[单项选择]Refrigeration system compressor crankcase sweating is an indication of （）.
A. insufficient lube oil circulating through the system
B. excessive circulation of lube oil through the system
C. insufficient refrigerant in the system
D. an overworked compressor
[单项选择]What is the function of thermostatic expansion valve in a compression refrigeration system?（）
A. nonexistent
B. for controlling pressure
C. for controlling superheat
D. for controlling the solenoid valve
[单项选择]A refrigeration system compressor crankcase is sweating or unusually coldThis is an indication of（）.
A. a shortage of refrigerant in the system
B. air in the system
C. an accumulation of liquid refrigerant in the crankcase
D. a shortage of oil in the crankcase
[单项选择]If a refrigeration system compressor crankcase is sweating, you should （）.
A. add refrigerant to the system
B. adjust the thermal expansion valve to the proper setting
C. adjust the float valve to the proper holding pressure
D. open the hand expansion valve
[单项选择]Internal combustion engine crankcase vent outlets must be equipped with （）
A. hinged rain guards
B. corrosion resistant flame screens
C. dipsticks for measuring oil levels
D. crankcase ventilation fans
[单项选择]
With regards to a diesel engine crankcase explosion, the most violent is the（）
(1) primary explosion
(2) secondary explosion
A. (1) only
B. (2) only
C. both (1) and (2)
D. neither (1) or (2)
[单项选择]Crankcase sweating in a refrigeration system is caused by （）.
A. a stuck solenoid valve
B. a shortage of refrigerant
C. too much oil in circulation
D. too much superheat
[单项选择]What following is not among the function of SOLAS ships?（）
A. receive shore-to-ship distress alerting
B. transmit ship-to-shore distress alerting
C. receive message for public correspondence
D. transmit and receive locating signals
[单项选择]What is the function of wearing rings found on some centrifugal pumps? （）
A. Absorb erosion of high velocity discharge stream
B. Seal pump shaft against entry of air
C. Isolate the outlet side from the inlet side
D. Dampen the turbulent discharge flow
[单项选择]The most common cause of lowering the crankcase lube oil flash point is （）.
A. more water contents
B. contamination with fuel oil
C. higher temperature
D. sufficient cooling of oil mist
[单项选择]If the refrigeration compressor crankcase is sweating, the cause may be due to （）.
A. a shortage of refrigerant
B. the compressor running continuously
C. liquid refrigerant returning to the compressor
D. the compressor short cycling on the high pressure cutout
[单项选择]A substantial increase in crankcase pressure could be an indication of （）
A. excessive lube oil pressure
B. the proper seating of new rings
C. a worn cylinder liner
D. a malfunctioning cylinder relief valve
[单项选择]An increase in crankcase pressure generally indicates（）
A. worn connecting rod bearings
B. worn engine cylinder liners
C. high cylinder firing pressure
D. stuck spring-loaded manhole covers
[单项选择]If a refrigeration crankcase compressor were short cycling on the low pressure cutout switch, the cause might be that the （）.
A. system was overcharged with refrigerant
B. system was low on refrigerant
C. suction valves were leaking slightly
D. relief valve was leaking slightly
[单项选择]Crankcase explosions in propulsion diesel result from（）
A. the splashing of lubrication oil by the crankshaft
B. the dilution of crankcase oil with particles of combustion
C. broken fuel lines spraying oil on the crankcase
D. the ignition of unburned fuel and air in the crankcase
[单项选择]（） that everything in the engine crankcase is correct, start up the crankcase lubricating oil pump.
A. To satisfy
B. To be satisfied
C. After satisfying
D. After being satisfied
[单项选择]What is the function of the command switchport trunk native vlan 999 on a？（）
A. It designates VLAN 999 for untagged traffic.
B. It blocks VLAN 999 traffic from passing on the trunk.
C. It createsa VLAN 999 interface.
D. It designates VLAN 999 as the default for all unkown tagged traffic.
