2ND 5

Question 1

The work of pumping consists of discharging a quantity of liquid or gas against a/an:

a) inlet
b) vacuum
c) resistance
d) volute

Answer 1

c) resistance

Question 2

The motion exerted by pumps on the fluids pumped may be due to:

a) reciprocating action
b) centrifugal action
c) jet action
d) all of the above

Answer 2

d) all of the above

Question 3

Fluid density, height fluid must be raised, pipe friction, and static pressure all relate to:

a) total pump head
b) positive suction head
c) static head only
d) dynamic suction lift only

Answer 3

a) total pump head

Question 4

Check valves are sometimes installed in the suction line of pumps to:

a) prevent over speeding
b) prevent suction loss or shutdown
c) control amount of fluid discharge
d) all three of the above

Answer 4

b) prevent suction loss or shutdown

Question 5

What type of pump can be operated with the discharge valve closed?

a) reciprocating
b) gear
c) screw
d) centrifugal

Answer 5

d) centrifugal

Question 6

What type of pump operates on the velocity, restriction principle?

a) centrifugal
b) rotary
c) screw
d) ejector

Answer 6

d) ejector

Question 7

What type of pump is best suited for the handling of dirty water?

a) non-positive displacement
b) rotary
c) positive displacement
d) ejector

Answer 7

a) non-positive displacement

Question 8

The purpose of the volute type of casing or diffusion vanes of centrifugal pumps is to:

a) increase the kinetic energy of the discharging fluid
b) increase the velocity of the discharging fluid
c) reduce the velocity and increase the pressure of the discharging fluid
d) reduce both the velocity and the pressure of the discharging fluid

Answer 8

c) reduce the velocity and increase the pressure of the discharging fluid

Question 9

The laws governing the temperature-pressure relations of the liquids explain why a force must be used to cause a liquid to flow into a pump and relate most nearly to:

a) net positive suction head
b) pump head
c) shut-off head
d) specific head

Answer 9

a) net positive suction head

Question 10

Inter-stage leakage in multi-stage centrifugal pumps is most usually controlled by the use of:
a) wearing rings

b) mechanical seals
c) packing
d) all of the above

Answer 10

a) wearing rings

Question 11

The purpose of wearing rings or labyrinth rings in centrifugal pumps is to:

a) control inter-stage losses
b) reduce recirculation losses
c) reduce maintenance costs
d) all three of the above

Answer 11

d) all three of the above

Question 12

The function of a lantern ring in the stuffing box of a centrifugal pump is to:

a) distribute sealing or lubricating water around the pump shaft
b) separate two different types of packing used in the stuffing box
c) equalize pressure applied to the packing by the gland nuts
d) bleed off packing gland leakage from the stuffing box

Answer 12

a) distribute sealing or lubricating water around the pump shaft

Question 13

In what part of a centrifugal pump is the kinetic energy in the fluid converted to potential or pressure energy?

a) the impeller
b) the casing
c) the labyrinth rings
d) none of the above

Answer 13

b) the casing

Question 14

The head generated by the centrifugal pump is always expressed in:

a) lbs/sq. in.
b) cu. ft/sec
c) feet of liquid
d) lb/sq. ft

Answer 14

c) feet of liquid

Question 15

One foot of pump head is a static force exerted by a column of water one foot high on an area of one square inch. It is equal to how many pounds of pressure?

a) 62.4
b) 7.4
c) 0.434
d) 0.343

Answer 15

c) 0.434

Question 16

Which one of the following conditions would normally act to increase the total pump head?

a) Installation of new clearance or wearing rings
b) Replacing old discharge piping with new piping
c) Extending the length of discharge piping
d) Repairing cavitation areas in impellers

Answer 16

c) Extending the length of discharge piping

Question 17

In a constant speed centrifugal pump, any increase in flow rate beyond that for which the pump is designed to handle will normally cause:

a) a drop in efficiency and an increase in discharge pressure
b) a drop in both efficiency and discharge pressure
c) a decrease in horsepower input to the pump
d) an increase in discharge pressure

Answer 17

b) a drop in both efficiency and discharge pressure

Question 18

Specific speed refers to or indicates:

a) type of pump
b) actual speed of the impeller
c) the speed a model of a given design would operate to discharge one gallon per minute against one foot head
d) speed in feet/sec of discharge flow

Answer 18

c) the speed a model of a given design would operate to discharge one gallon per minute against one foot head

Question 19

The most efficient type of impeller to use for conditions of small capacities and high heads would generally be the:

a) radial
b) Francis
c) propeller
d) screw

Answer 19

a) radial

Question 20

Excessive vapors in the inlet or suction side of a liquid pump will cause the pump to:

a) slow down
b) reverse
c) lose prime
d) speed up

Answer 20

c) lose prime