WorksheetsDay 38-Oct 28-worksheet-Diploma-Hydraulic pumps part 1
Total questions: 15
Worksheet time: 12mins
Cavitation in a centrifugal pump is most likely to begin at which location?
Delivery valve
Middle of impeller eye
Suction side near the impeller inlet
Casing exit
For multiple centrifugal pumps arranged in series, the main advantage is:
Increased discharge
Increased total head
Reduced suction lift
Lower priming height
NPSH available becomes less than NPSH required. What is the first observable symptom?
Drop in voltage
Velocity pulsation at discharge
Sudden rise in motor temperature
Pitting/erosion near impeller eye
Vortex casing is inserted between impeller and volute casing primarily to:
Reduce priming time
Increase specific speed
Reduce eddies & turbulence losses
Allow higher suction lift
In a double-acting reciprocating pump, the discharge per revolution is:
Half that of a single-acting pump
Same as a single-acting pump
Twice that of a single-acting pump
1.5 times that of a single-acting pump
Shut-off head is defined as the head:
Corresponding to rated discharge
When delivery valve is partially closed
Corresponding to zero discharge
Corresponding to maximum flow
In a centrifugal pump, increase in suction lift always increases cavitation risk.
True
False
The theoretical maximum suction lift of a centrifugal pump is (a) m of water.
The impeller of a centrifugal pump has (a) curved vanes.
The speed at which a geometrically similar pump delivers 1 m³/s at 1 m head is called (a) .
………………is the process of completely filling the pump casing and suction pipe to remove air.
(a)
A double-acting reciprocating pump delivers (a) discharges per crank revolution.
Cavitation mainly occurs when local pressure < (a) pressure of liquid.
The area (A) of a single-acting reciprocating pump is 0.05 m², the length of stroke (L) is 0.4 m, and the speed is 30 rpm. What is the theoretical discharge per second?
(a)
If atmospheric head is 10.3 m and vapour head = 0.3 m, Maximum theoretical suction lift is…………
(a)
