单项选择题
A.reciprocating pumps B.positive displacement pumps C.centrifugal pumps D.centripetal pumps
Gear pumps are of positive displacement type pumps beca...
单项选择题Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.
A.depending on B.in relative to C.regardless of D.because of
The gear and screw pumps are classified as （）.A.variabl...
单项选择题The gear and screw pumps are classified as （）.
A.variable stroke pumps B.multistage pumps C.positive displacement pumps D.triple-ported pumps
Through a （） pump, the liquid is transferred from the s...
单项选择题Through a （） pump, the liquid is transferred from the suction to the discharge by the mechanical variation of the volume of a chamber or chambers.
A.positive displacement B.ejector C.centrifugal D.air compressor
