You discover that your feed water pump is not delivering sufficient water. A possible cause is

You discover that your feed water pump is not delivering sufficient water. A possible cause is

a) the impeller is plugged
b) the suction lift is too low
c) the discharge head is not high enough
d) there is too much water in the pump
e) the foot valve is fully open







Answer: A

If a pump is running and has no discharge pressure, what will you do?

If a pump is running and has no discharge pressure, what will you do?

a) close the suction valve a little
b) open the lubrication valve
c) check the lubricant level
d) check to see if the suction valve is open
e) close the discharge valve




Answer: D

If pump speed is too high

If pump speed is too high

a) the driver may be overloaded
b) discharge pressure will be below normal
c) no liquid will be delivered
d) the pump will lose its prime after starting
e) there will be air or gas in the liquid





Answer: A

A plugged impeller symptom or result will be

A plugged impeller symptom or result will be

a) air leaks in suction line and stuffing boxes
b) wrong direction of rotation
c) loss of prime
d) an overheated stuffing box
e) no liquid being delivered




Answer: E

If the packing gland of a centrifugal water pump is leaking too much, you should

If the packing gland of a centrifugal water pump is leaking too much, you should

a) tighten up the gland until all leakage has been stopped
b) tighten up the gland but permit a slight amount of leakage
c) tighten up the gland as far as is possible
d) throttle the suction valve a little
e) tighten up the gland until there is 10% leakage





Answer: B

Shaft misalignment during operation of a pump can be caused by bearing wear, thermal expansion, and

Shaft misalignment during operation of a pump can be caused by bearing wear, thermal expansion, and

a) shaft flexing
b) throttling of the discharge valve
c) overloading the pump
d) loss of lubricant
e) improper installation





Answer: A

The component of a mechanical seal which prevents axial leakage is

The component of a mechanical seal which prevents axial leakage is

a) the seal ring
b) packing
c) the mating ring
d) the O-ring
e) a diaphragm





Answer: D

Any leakage occurring through the surfaces of a mechanical seal will

Any leakage occurring through the surfaces of a mechanical seal will

a) not be visible to the operator
b) result in an audible sound and be readily noticed
c) be indicated by pump vibrations
d) be axial to the shaft
e) be radial to the shaft




Answer: E

Lantern rings: 1. prevent liquid leakage from the pump 2. are fed by a liquid 3. provide a seal to prevent air from entering the pump 4. are mostly used on high lift pumps

Lantern rings:
1. prevent liquid leakage from the pump
2. are fed by a liquid
3. provide a seal to prevent air from entering the pump
4. are mostly used on high lift pumps

a) 1, 2, 3
b) 2, 3
c) 2, 3, 4
d) 3, 4
e) 1, 2






Answer: C

Compression type packing: 1. prevents air from entering the pump 2. reduces the maintenance cost on pumps 3. protects the shaft from scoring and corrosion 4. is used with all mechanical seals

Compression type packing:
1. prevents air from entering the pump
2. reduces the maintenance cost on pumps
3. protects the shaft from scoring and corrosion
4. is used with all mechanical seals

a) 1
b) 2, 3
c) 2, 3, 4
d) 1, 2
e) 1, 3




Answer: D

Mechanical seals: 1. are used where leakage is objectionable 2. replace stuffing boxes 3. provide a better seal than packing 4. are less costly than stuffing boxes

Mechanical seals:
1. are used where leakage is objectionable
2. replace stuffing boxes
3. provide a better seal than packing
4. are less costly than stuffing boxes

a) 1, 2
b) 1, 2, 3
c) 2, 3
d) 2, 3, 4
e) 2, 4




Answer: B

A stuffing box: 1. stops air leaking into the casing when the pressure is below atmospheric 2. decreases leakage out of the casing when the pressure is above atmospheric 3. is always supplied with a lantern ring 4. is filled with packing

A stuffing box:
1. stops air leaking into the casing when the pressure is below atmospheric
2. decreases leakage out of the casing when the pressure is above atmospheric
3. is always supplied with a lantern ring
4. is filled with packing

a) 1, 3
b) 1, 4
c) 2, 3
d) 2, 3, 4
e) 1, 2, 4



Answer: E

Wearing rings: 1. are used on impellers 2. are used on the casing 3. give protection to the shaft 4. reduce the maintenance cost of the pump

Wearing rings:
1. are used on impellers
2. are used on the casing
3. give protection to the shaft
4. reduce the maintenance cost of the pump

a) 1, 2, 3
b) 1, 2, 4
c) 2, 3, 4
d) 2, 3
e) 3, 4




Answer: A

Wear rings are usually constructed of

Wear rings are usually constructed of

a) ceramics or aluminum
b) graphite or bronze
c) bronze or cast iron
d) steel or alloy steel
e) wrought iron or pig iron



Answer: C

Pump wear rings are installed on an impeller by set screws, threading or

Pump wear rings are installed on an impeller by set screws, threading or

a) shrinking
b) welding
c) brazing
d) soldering
e) forging




Answer: A

Mechanical seals:

Mechanical seals:

a. Allow the pump to be run dry
b. Are used where leakage is objectionable
c. Replace seal cages
d. Withstand shaft misalignment and vibration better than packing
e. Are less costly than packing





Answer: B

Most pump troubles occur:

Most pump troubles occur:

a. After about six months of continuous service
b. Due to vapour binding
c. During initial start up
d. Due to wrong rotation
e. Because of inadequate operator training




Answer: C

A slight leakage is desired between the pump shaft and the packing in order to:

A slight leakage is desired between the pump shaft and the packing in order to:

a. Prevent the ingress of air
b. Increase pump capacity and efficiency
c. Prevent wearing of the wear rings
d. Lubricate the shaft and packing
e. Prevent the pump from vapour locking

Answer: D

The area around a pump shaft, where packing material is placed to reduce leakage past the shaft, is known as a:

The area around a pump shaft, where packing material is placed to reduce leakage past the shaft, is known as a:

a. Seal box
b. Stuffing box
c. Seal cage
d. Wearing ring
e. Gear box

Answer: B

While a pump is operating, your inspection should include the following:

While a pump is operating, your inspection should include the following:

a. Ensure water freely flows from the packing
b. Ensure water is dripping from the mechanical seals
c. Check the suction and discharge pressures
d. Make sure the shafts are in alignment
e. Prime the pump.






Answer: C