throttling the pressure line
changing the speed of the rotor
either A or B
None of the above is tree
第1题:
The amount of fluid delivered by a positive displacement pump can be regulated by _____.
A.throttling the pressure line
B.changing the speed of the driving rotor
C.either A or B
D.None of the above is tree
第2题:
What causes cavitation in a centrifugal pump ________.
A.Vapor pockets in the flow stream
B.Rough impeller surfaces
C.Worn wearing rings
D.Heavy fluid in the flow stream
第3题:
Throttling in the _____ line of a centrifugal pump involves the risk of the pump cavitation.
A.suction
B.exhaust
C.pressure
D.discharge
第4题:
excessive internal leakage in the pump
low discharge pressure and fluid flow
excessive fluid level in the hydraulic reservoir
operation of the pump at 100% efficiency
第5题:
the mechanical seal
packed stuffing boxes
either A or B
neither A nor B
第6题:
The amount of fuel delivered by a helical plunger fuel injection pump is controlled by ______.
A.varying the pump discharge pressure
B.varying the pump return pressure
C.rotation of the pump plunger
D.rotation of the pump barrel
第7题:
Single stage or multistage
High pressure or low pressure
Open or close coupled
Horizontal or vertical
第8题:
Overheating of the hydraulic fluid in an electro-hydraulic anchor windlass can result from a/an( ).
A.overload on the pump motor
B.low fluid level in the reservoir
C.low fluid viscosity around the shaft seal
D.high oil level in the sump
第9题:
In order for a fluid to be pumped, a fluid must be made to flow
A substance must be cold in order for it to be pumped
The kinetic energy imparted by the pump can be used to force a liquid through a hydraulic system
A pump must receive its energy from an external source
第10题:
one size larger than the pump discharge nozzle
the same size as the pump discharge nozzle
one size smaller than the pump discharge nozzle
installed with a short radius elbow at the pump