A.microscopic steel shavings
B.abrasive waste
C.anti-oxidant compounds
D.oxidation by-products
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A.increase the capacity of the coil
B.increase the superheat at the bulb
C.deliver more refrigerant to the coil
D.decrease the capacity of the coil
A.Centrifugal
B.Reciprocating
C.Gear
D.Rotary
A.a high suction head
B.rotating rings
C.badly worn bearings
D.a loose stuffing box gland
A.solenoid valve to seize
B.compressor to hunt
C.formation of flash gas in the liquid line
D.expansion valve to freeze open
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
最新試題
One cause of high head pressure occurring in a refrigeration system can be （）.
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
The general purpose of a heat exchanger is to （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
The major source of chemical contaminants in hydraulic fluid is （）.
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.