A.filled with water
B.purged
C.cleared of air
D.None of the above is true
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A.Safety valves
B.Water tubes
C.Steam stop valves
D.Blow down valves
A.water-tube
B.fire-tube
C.exhaust gas
D.None of the above is true
A.water-tube
B.fire-tube
C.exhaust gas
D.none of the above
A.scaled
B.informed
C.leaky
D.deformed
A.sealed
B.cracked
C.shape changed
D.deformed
最新試題
One cause of high head pressure occurring in a refrigeration system can be （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
Which of the listed pumps is NOT a positive displacement pump?（）
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
Which of the following statements is correct concerning heat transfer?（）
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.