单项选择题
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
The refrigerant leaves the evaporator of a refrigeratio...
单项选择题The refrigerant leaves the evaporator of a refrigeration system as a low pressure （）.
A.sub-cooled liquid B.high temperature liquid C.oil saturated liquid D.superheated vapor
When operating with a negative suction head, which of t...
单项选择题When operating with a negative suction head, which of the following types of pumps will require priming?（）
A.Reciprocating B.Centrifugal C.Rotary D.Gear
