Which of the following are components of a mechanical seal? （）
(1) stationary ring
(2) rotational ring
(3) packing
(4)spring
A.(1), (2) and (3)
B.(1), (2) and (4)
C.(2), (3) and (4)
D.None of the above
您可能感興趣的試卷
你可能感興趣的試題
A.variable stroke pumps
B.multistage pumps
C.positive displacement pumps
D.triple-ported pumps
A.mixed-flow pump
B.axial-flow pump
C.centrifugal pump
D.displacement pump
A.on top cover
B.on sides of bowl
C.in drain line on the discs
D.on the discs
A.oil
B.sea water
C.refrigerant
D.fresh water
A.a flash generator
B.a flash evaporator
C.a vacuum boiling evaporator
D.a boiler
最新試題
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
The output volume of a positive fixed displacement pump can be changed only by （）.
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
A grease gun is generally used to lubricate a （）.
Which of the listed pumps is NOT a positive displacement pump?（）
Low compressor head pressure in a refrigeration system can be caused by（）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
A salinity indicator is used to determine the （）.
The major source of chemical contaminants in hydraulic fluid is （）.