单项选择题
Which of the following statements is correct with regards to the operation of a centrifugal cargo pump?（）
A.Oil is discharged from the impeller through the outlet
B.Gravity causes the oil to flow toward the discharge
C.The self-priming feature of the centrifugal pump enables it to draw its own suction as it starts
D.The discharge capacity varies directly with the speed of the impeller
相关考题
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单项选择题
The static suction head of is the （）
A.distance of the suction liquid level above the line of the pump
B.distance the suction liquid level is below the center line of the pump
C.force necessary to overcome frictional losses in the pump and piping
D.amount in inches of mercury the total suction head is below atmospheric pressure -
单项选择题
A pump is defined as device that（）
A.produces pressure
B.imparts energy to a fluid to move it from level ‘A’ to level ‘B’
C.creates a vacuum to move a liquid in all installation
D.is to develop a pressure differential -
单项选择题
A distorted furnace in a fire-tube auxiliary boiler may be the result of （）
A.firing for extended periods in the low fire mode
B.overheating, due to waterside deposits
C.varying the water level above the crown sheet
D.carrying excessive alkalinity in the boiler water
