Caustic Corrosion

Question 1

1. Which of the following material(s) are common Caustics? *This may have more than one correct answer, please select all answers that apply

A. COK
B. C3H8
C. HCl
D. KOH
E. MgO2
F. NaOH

Answer 1

D. KOH
F. NaOH

Question 2

2. Caustic Corrosion normally occurs in:

A. heated areas, where water evaporates & the Caustic strength concentrates.
B. in non-stress relieved CS equipment
C. Only CS piping & equipment
D. areas with a low pH

Answer 2

A. heated areas, where water evaporates & the Caustic strength concentrates.

Question 3

3. Which of the following materials is NOT subjected to Caustic Corrosion?

A. Carbon Steel
B. Chromes
C. 400-Series SS
D. Nickel Alloys

Answer 3

D. Nickel Alloys

Question 4

4. At what temperature does 300 SS START to be affected by Caustic Corrosion? (Open Book)

A. 40-125°F
B. 140-350°F
C. 160-210°F
D. 180-270°F

Answer 4

C. 160-210°F

Question 5

5. Which of the following is the MOST significant factor affecting Caustic Corrosion?

A. Presence of Caustic
B. Gravitation pull of the Moon
C. The financial value of the Operating Unit
D. The number of Corrosion Specialists that you can fit in VW Bug

Answer 5

A. Presence of Caustic

Question 6

6. Which of the following is NOT a common use of Caustic in the petrochemical industry?

A. Added to Boiler Feedwater in small amounts
B. Used to decrease pH
C. Used to neutralize acids
D. Used as Reactant to remove Sulfur Compounds

Answer 6

B. Used to decrease pH

Question 7

7. In high strength caustic solutions, Caustic Corrosion Starts to cause uniform corrosion of Carbon Steel when the process temperature exceeds: (Open Book)

A. 140°F
B. 170°F
C. 225°F
D. 350°F

Answer 7

B. 170°F

Question 8

8. For localized Caustic Corrosion to occur in routine equipment, there must be a(n): (Open Book)

A. process temperature that exceeds 500°F
B. long period of time
C. concentrating method that builds the Caustic’s strength
D. unit upset that provides high strength Caustic

Answer 8

C. concentrating method that builds the Caustic’s strength

Question 9

9.Which of the following can contribute to Caustic Corrosion in a caustic piping system?

A. Dead legs
B. Heat Tracing
C. Higher Flange Class
D. Velocity

Answer 9

B. Heat Tracing

Question 10

10. Caustic Corrosion is most often associated with:

A. Boilers and steam generating equipment
B. Furnaces
C. Overhead systems
D. Tank bottoms

Answer 10

A. Boilers and steam generating equipment

Question 11

11. Caustic Corrosion normally appears as:

A. Isolated pitting
B. Concentrated pitting
C. Localized metal loss often with grooving
D. uniform metal loss

Answer 11

C. Localized metal loss often with grooving

Question 12

12. If Caustic is occurring, it may be missed because:

A. Deposits can fill up the corroded areas
B. the corrosion often occurs in crevices
C. this corrosion mechanism causes extremely tight cracks
D. it is always very localized and random

Answer 12

A. Deposits can fill up the corroded areas

Question 13

13. In steam systems, Caustic Corrosion is best prevented by:

A. aggressive monitoring
B. the constant addition of an acid to neutralize the caustic
C. thorough inspection program
D. proper design

Answer 13

D. proper design

Question 14

14. Which of the following materials could be used when the process has a high strength Caustic solution at elevated temperature?

A. High chromes alloys
B. Nickel alloys
C. Molybdenum alloys
D. Kryptonite alloys

Answer 14

B. Nickel alloys