Power engineering 4B Book 2 Pumps and compressors
Questions With Complete Solutions
A centrifugal pump consist of
a) An impeller surrounded by a casing
b) Gears rotating in a housing
c) Sliding vanes
d) A pulsating disc Correct Answers a
A circulating pump, known as a cooling water pump, is usually
a) Connected with some kind of heat exchanger system
b) A once-through device
c) A reciprocating pump
d) A small capacity pump Correct Answers a
A diffuser pump
a) Does not have a volute
b) Does not have to be primed
c) Has high suction lift
d) Is more effective at changing velocity to pressure than a
volute pump Correct Answers d
A inspection of a pump that is in operation should include
a) Ensuring water flows freely from the packaging
b) Ensuring water drips from the mechanical seals
c) Checking that the suction and discharge pressures are correct
d) Re-priming the pump Correct Answers c
,A mechanical pump seal
a) Does not need cooling
b) Can be designed for high pressure service
c) Will cause more wear on the shaft than a packing seal
d) Will have a substantial amount of leakage Correct Answers b
A pump is capable of suction lift due to
a) its ability to convert kinetic energy into potential energy
b) the speed at which it operates
c) its input power
d) atmospheric pressure Correct Answers d
A rotary pump:
Select one:
a. Is a dynamic pump
b. Should be equipped with a relief valve
c. Has severe discharge pulsations
d. Is silent in operation Correct Answers b
A speed-increasing gear is commonly used on
a) rotary lobe compressors
b) screw compressors
c) sliding vane compressors
d) lobe compressors Correct Answers b
A stuffing box
, a) Stops air leaking out of the casing when the pressure is above
atmospheric
b) Promotes casing leakage when the pressure is above
atmospheric
c) Is filled with packing
d) Is always supplied with a lantern ring Correct Answers c
a volute type pump
a) is a positive displacement pump
b) has spiral casing with an increasing cross sectional area
c) reduces velocity in the discharge nozzle
d) is a regenerative type pump Correct Answers b
An advantage of a pump using a mechanical seal is
a) Lower first cost
b) Less maintenance
c) Less lubrication
d) Ease of repair Correct Answers b
An air compressor axillary which will decrease the power
requirement is the
a) Aftercooler
b) Intercooler
c) Receiver
d) Diffuser Correct Answers b
an air compressor may be automatically started and stopped by a
pressure switch, which is usually found connected to the
Questions With Complete Solutions
A centrifugal pump consist of
a) An impeller surrounded by a casing
b) Gears rotating in a housing
c) Sliding vanes
d) A pulsating disc Correct Answers a
A circulating pump, known as a cooling water pump, is usually
a) Connected with some kind of heat exchanger system
b) A once-through device
c) A reciprocating pump
d) A small capacity pump Correct Answers a
A diffuser pump
a) Does not have a volute
b) Does not have to be primed
c) Has high suction lift
d) Is more effective at changing velocity to pressure than a
volute pump Correct Answers d
A inspection of a pump that is in operation should include
a) Ensuring water flows freely from the packaging
b) Ensuring water drips from the mechanical seals
c) Checking that the suction and discharge pressures are correct
d) Re-priming the pump Correct Answers c
,A mechanical pump seal
a) Does not need cooling
b) Can be designed for high pressure service
c) Will cause more wear on the shaft than a packing seal
d) Will have a substantial amount of leakage Correct Answers b
A pump is capable of suction lift due to
a) its ability to convert kinetic energy into potential energy
b) the speed at which it operates
c) its input power
d) atmospheric pressure Correct Answers d
A rotary pump:
Select one:
a. Is a dynamic pump
b. Should be equipped with a relief valve
c. Has severe discharge pulsations
d. Is silent in operation Correct Answers b
A speed-increasing gear is commonly used on
a) rotary lobe compressors
b) screw compressors
c) sliding vane compressors
d) lobe compressors Correct Answers b
A stuffing box
, a) Stops air leaking out of the casing when the pressure is above
atmospheric
b) Promotes casing leakage when the pressure is above
atmospheric
c) Is filled with packing
d) Is always supplied with a lantern ring Correct Answers c
a volute type pump
a) is a positive displacement pump
b) has spiral casing with an increasing cross sectional area
c) reduces velocity in the discharge nozzle
d) is a regenerative type pump Correct Answers b
An advantage of a pump using a mechanical seal is
a) Lower first cost
b) Less maintenance
c) Less lubrication
d) Ease of repair Correct Answers b
An air compressor axillary which will decrease the power
requirement is the
a) Aftercooler
b) Intercooler
c) Receiver
d) Diffuser Correct Answers b
an air compressor may be automatically started and stopped by a
pressure switch, which is usually found connected to the
