单项选择题
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
Which of the listed pumps is NOT a positive displacemen...
单项选择题Which of the listed pumps is NOT a positive displacement pump?（）
A.Centrifugal B.Reciprocating C.Gear D.Rotary
Heavy wear in a particular area of the inner circumfere...
单项选择题Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
A.a high suction head B.rotating rings C.badly worn bearings D.a loose stuffing box gland
A pressure drop through the refrigerant liquid line may...
单项选择题A pressure drop through the refrigerant liquid line may cause （）.
A.solenoid valve to seize B.compressor to hunt C.formation of flash gas in the liquid line D.expansion valve to freeze open
