单项选择题
A butterfly valve consists basically of a disc pivoted across the bore of a ring body having the same radial dimensions as the pipe in which it is fitted.According to the above sentence, which of the following statements is not true?（）
A.The diameter of a disc is the same as the outer diameter of the pipe
B.We can infer that the valve is opened or closed by rotating the spindle
C.A butterfly valve comprises a disc and a ring body
D.The profile of the butterfly valve is a ring body
相关考题
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单项选择题
Unlike the globe valve, gate valves give full bore flow without change of direction, such a valve is not suitable to partially open operationAccording to the above sentence, which of the following statements is not true?（）
A.The globe valve may be suitable for partially open operation
B.The globe valve will give full bore flow with change of direction
C.The gate valve gives full bore flow with change of direction
D.The gate valve is suitable for full bore operation only -
单项选择题
The globe valve has a bulbous body, housing a valve seat and screw down plug or disc arranged at right angles to the axis of the pipeAccording to the above sentence, which of the following statements is not true?（）
A.The profile of the valve is like a globe
B.The valve seat is set into the bulbous body
C.The plug or disc of the valve is made vertical to the axis of the pipe
D.The valve seat is located at right side of the plug or disc -
单项选择题
Cocks and valves control or interrupt flow, and have internal passages arranged so that they can be restricted or closed: in cocks, by rotating the plug, and in valves, by lowering, raising or rotating a disc in relation to a seating surfaceAccording to the above sentence, which of the following statements is not true?（）
A.Flows of fluids can be restricted by both cocks and valves
B.There are seats in the internal passages of valves
C.A disc of valve only moves up and down
D.We can infer that there is a bore in cock ping
