你可能感興趣的試題

單項(xiàng)選擇題

Under normal conditions, the refrigerant enters the compressor in an operating refrigeration system as a （）.

A.liquid
B.dry saturated gas
C.wet saturated gas
D.superheated vapor

單項(xiàng)選擇題

Some vessels are equipped with a water lubricated stern robeWhen at sea, operating under normal conditions, the water service valve from the ships saltwater system to the bearing should be （）.

A.closed, and no leakage permitted across the shaft packing
B.closed, and only slight leakage permitted across the shaft packing
C.open, and no leakage permitted across the shaft packing
D.open, and only slight leakage permitted across the shaft packing