單項(xiàng)選擇題Before starting a reciprocating, steam-driven pump that has been idle for a period of time, you should （）.

A.open the steam line mot valve
B.drain the steam cylinder
C.close the steam cylinder drains
D.open the liquid cylinder drains


您可能感興趣的試卷

你可能感興趣的試題

1.單項(xiàng)選擇題When air becomes trapped in the hydraulic fluid of a steering system, the （）.

A.rudder will respond sluggishly
B.hydraulic rams will over-speed
C.sight glass will show bubbles
D.ram relief valves will lift

2.單項(xiàng)選擇題If a refrigeration system were short of refrigerant, the condition would result in （）.

A.continuous running of the compressor
B.high suction pressure
C.high discharge pressure
D.short cycling of the compressor on the water failure switch

3.單項(xiàng)選擇題Condensate must be drained from the intercooler and after-coolers of an air compressor because （）.

A.the cooling effect of the condensate reduces the compressors efficiency
B.a danger of explosion exists whenever water is present in a compressor
C.water causes erratic operation of pneumatic components
D.the volumetric capacity of the first stage is reduced if water remains

4.單項(xiàng)選擇題In the refrigeration system, a shortage of refrigerant is indicated by （）.

A.the compressor short cycling on high pressure cut out switch
B.high suction pressure
C.high head pressure
D.bubbles in the sight glass

5.單項(xiàng)選擇題Which of the following conditions must exist for heat to flow from one object to another?（）

A.The two objects must be in physical contact
B.The two objects must be the same size
C.There must be an existing temperature differential
D.There must be an existing weight differential