SPED Corrosion Prevention & Protection 3

Question 1

In impressed current cathodic protection (ICCP) systems, what device converts AC power to DC and controls the output current?

Accepted Answer

Rectifier

Answer

A rectifier converts AC utility power to DC and allows adjustment of voltage and current output to maintain adequate cathodic protection levels.

Question 2

What is the purpose of a test station installed along a cathodically protected pipeline?

Accepted Answer

To allow pipe-to-soil potential measurements without excavation

Answer

Test stations provide accessible connection points so technicians can measure pipe-to-soil potentials and monitor cathodic protection effectiveness without excavating.

Question 3

Which form of corrosion preferentially attacks grain boundaries in a metal?

Accepted Answer

Intergranular corrosion

Answer

Intergranular corrosion attacks along grain boundaries where chromium depletion or precipitates create locally anodic zones, common in improperly heat-treated stainless steels.

Question 4

Hydrogen-induced cracking (HIC) in pipelines is most commonly associated with which environment?

Accepted Answer

Wet H2S (sour) service

Answer

HIC occurs in wet H2S (sour) service where atomic hydrogen generated at the pipe surface diffuses into the steel and recombines at internal defects, creating internal pressure and cracking.

Question 5

What is the primary purpose of adding a corrosion inhibitor to a pipeline carrying wet natural gas?

Accepted Answer

Form a protective film on the pipe interior surface

Answer

Corrosion inhibitors adsorb onto the metal surface to form a protective film that reduces the rate of electrochemical corrosion reactions.

(SPED) Society of Piping Engineers and Designers Certification Practice Test

(SPED) Society of Piping Engineers and Designers Certification Practice Test

SPED Corrosion Prevention & Protection 3