A.two or more impellers housed together in one casing and mounted on a single shaft
B.a single stepped impeller mounted in a progressively staged casing
C.a large radial clearance between the impeller and casing to prevent overheating due to
D.an increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stages
您可能感興趣的試卷
你可能感興趣的試題
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
A.a stuck solenoid valve
B.a shortage of refrigerant
C.too much oil in circulation
D.too much superheat
A.trick-wheel
B.follow-up control
C.six-way valve
D.Rapson slide
A.stress
B.strain
C.shear strength
D.ultimate tensile strength
A.increase discharge pressure
B.decrease pump capacity
C.decrease pump cavitation
D.decrease reaction ring clearance
最新試題
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
Which of the listed pumps is NOT a positive displacement pump?（）
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
A pressure drop through the refrigerant liquid line may cause （）.
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
The major source of chemical contaminants in hydraulic fluid is （）.
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.