Boiler Water & Steam Condensate Corrosion

Question 1

1. Boiler water and condensate corrosion is primarily the result of dissolved: * this may have more than one correct answer, please select all answers that apply

A. carbon dioxide
B. helium
C. nitrogen
D. oxygen
E. Sulfur trioxide

Answer 1

A. carbon dioxide
D. oxygen

Question 2

2. FAC can affect the rate of boiler water and condensate corrosion. What is FAC?

A. Ferritic Aerated Corrosion
B. Flow Accelerated Corrosion
C. Field Attenuated Corrosion
D. Focal Anodic Carburization
E. Field Anodic Concentration

Answer 2

B. Flow Accelerated Corrosion

Question 3

3. Boiler water and condensate corrosion primarily affects which materials?

A. Carbon steel
B. Carbon steel and low alloys
C. 300 series stainless steels
D. Most of the commonly used plant materials

Answer 3

B. Carbon steel and low alloys

Question 4

4. Which is NOT a major factor associated with boiler water and condensate corrosion?

A. Operating pressure
B. process pH
C. concentration of dissolved gases
D. Temperature

Answer 4

A. Operating pressure

Question 5

5. Protection in a boiler from Boiler Feed Water Corrosion is accomplished by: (open book)

A. Injecting chlorines to kill microbiological bugs
B. injecting caustic to lower the pH to < 4.0
C. lowering solid content in boiler feed water to less than 50 ppm
D. maintaining a protective corrosion layer of magnetite (FE3O4)

Answer 5

D. maintaining a protective corrosion layer of magnetite (FE3O4)

Question 6

6. Boiler Feed Water Corrosion can occur if the:

A. Boiler blow down system is not working properly
B. Caustic injection system is not working properly
C. Deaeration system is not working properly
D. Superheater tubes experience a “hot-spot”

Answer 6

C. Deaeration system is not working properly

Question 7

7. Corrosion from oxygen in boiler feed water usually creates:

A. Uniform corrosion
B. Isolated pitting
C. transgranular cracking
D. intergranular cracking

Answer 7

B. Isolated pitting

Question 8

8. Carbon Dioxide Corrosion usually creates:

A. Uniform corrosion
B. Isolated pitting
C. Intergranular cracking
D. smooth or grooving corrosion
E. hard and brittle zones

Answer 8

D. smooth or grooving corrosion

Question 9

9. What treatment is used to prevent Boiler Feed Water Corrosion?

A. Oxide scavengers are added to the process
B. Oxygen scavengers are added to the process
C. Sulfide scavengers are added to the process
D. Sulfur scavengers are added to the process

Answer 9

B. Oxygen scavengers are added to the process

Question 10

10. To minimize the potential for FAC, the pH of BFW should be maintained at: (Open Book)
    A. 4.6 TO 6.8 pH
    B. 6.2 TO 7.8 pH
    C. 7.4 TO 8.5 pH
    D. 9.2 TO 9.6 pH

Answer 10

D. 9.2 TO 9.6 pH

Question 11

11. What method is used to assure Boiler Feed Water corrosion is NOT occurring?

A. Laboratory chemical analysis of BFW
B. Profile RT at turbulent areas
C. Profile RT at stagnant areas
D. Spot UT readings at turbulent areas

Answer 11

A. Laboratory chemical analysis of BFW

Question 12

12. What NDE method is most often used to check for Boiler Feed Water Corrosion on an operating boiler?

A. Acoustic emission
B. AUBT
C. Thermography
D. No practical NDE method for hot boilers

Answer 12

D. No practical NDE method for hot boilers