单项选择题
A.Pressure-reducing valve B.Unloading valve C.Counterbalance valve D.Pressure-relief valve
If a centrifugal bilge pump were continually operated w...
单项选择题If a centrifugal bilge pump were continually operated with the discharge valve closed the （）.
A.motor overload would open B.relief valve would open C.pump would eventually overheat D.motor would overheat
In order to accurately measure very low pressures, whic...
单项选择题In order to accurately measure very low pressures, which of the instruments listed should be used?（）
A.Compound gage B.Bonrdon tube C.Manometer D.Deadweight gage
Reduced capacity, accompanied by vibration and noise at...
单项选择题Reduced capacity, accompanied by vibration and noise at the suction of a centrifugal pump is a result of （）.
A.cavitation B.water hammer C.fluid friction D.steam knock
