单项选择题
If a centrifugal pump were continually operated with the discharge valve closed, the （）.
A.motor controller overload would open B.pump would eventually overheat C.relief valve would continuously cycle open D.motor would overheat
单项选择题 A double suction centrifugal pump impeller has been installed in the reverse direction, and will （）.
单项选择题 Hydraulic machinery failures are commonly caused by misalignment of the system components and by （）.
单项选择题 Air compressor receivers should be “blown down” at least （）.
