Unit 2 Pumps and Compressors

Question 1

Positive displacement compressors:
Select one:
a. Cannot deliver pulsation-free air
b. Must have suction and discharge valves
c. Must all use internal lubrication
d. Could be single stage with three cylinders

Answer 1

d. Could be single stage with three cylinders

Question 2

Centrifugal compressors:
Select one:
a. Are used for high pressure and low flow
b. Could be of the multi-stage type
c. Must have a safety valve on the discharge when steam driven
d. Require inlet and discharge valves

Answer 2

b. Could be of the multi-stage type

Question 3

A circulating pump, known as a cooling water pump, is usually:
Select one:
a. Connected with some type of heat exchanger system
b. A once-through device
c. A reciprocating pump
d. A small capacity pump

Answer 3

a. Connected with some type of heat exchanger system

Question 4

Flexible couplings will compensate for:
Select one:
a. Overheating of packing 
b. unavoidable shaft misalignment  
c. Bearing failure 
d. Impeller imbalance

Answer 4

b. unavoidable shaft misalignment

Question 5

Centrifugal pumps convert rotating mechanical energy into kinetic energy then:
Select one:
a. Discharge the kinetic energy
b. Back to mechanical energy
c. Into potential energy in the form of pressure
d. Into centrifugal force

Answer 5

c. Into potential energy in the form of pressure

Question 6

Another name for a lantern ring, used in a pump is:
Select one:
a. Packing box
b. Packing ring
c. Rotating seal
d. Seal cage

Answer 6

d. Seal cage

Question 7

Compression type packing:
Select one:
a. May be saturated with a lubricating material
b. Reduces the maintenance cost on the pump
c. Protects the shaft from scoring and corrosion
d. Is used with all mechanical seals

Answer 7

a. May be saturated with a lubricating material

Question 8

Proper priming and venting of a pump is important, especially if:
Select one:
a. The medium being pumped is high temperature
b. The medium being pumped contains suspended solids
c. A mechanical seal is used
d. The pump has a stuffing box and lantern ring

Answer 8

c. A mechanical seal is used