单项选择题
One of the main differences between the various types of screw pumps is in the （）.
A.stuffing box diameter
B.direction of rotation of the screws
C.pitch of the screws
D.type of driving gears
点击查看答案&解析
相关考题
-
单项选择题
The temperature at which water vapor in the atmosphere begins to condense is called the （）.
A.dew point temperature
B.condensation temperature
C.psychometric temperature
D.absolute humidity temperature -
单项选择题
The tendency for lubricating oil to thin out at high temperatures and thicken at low temperatures will be characterized by a （）.
A.low viscosity index
B.high viscosity index
C.high neutralization number
D.low demulsibility quality -
单项选择题
Increasing the speed of a rotary pump above its rated speed will result in which of the following conditions to occur?（）
A.Loss of suction
B.Increased clearances
C.Decreased clearance
D.Decreased slippage
