Exam API-571 All QuestionsBrowse all questions from this exam
Question 24

Hydrogen blisters may form as surface bulges on the ID, the OD on within the wall thickness of a pipe or pressure vessel. Blistering occurs from hydrogen generated by ______, not hydrogen gas from the process stream.

    Correct Answer: B

    Hydrogen blisters form due to the presence of hydrogen generated by corrosion. This process is different from hydrogen gas coming from the process stream. During corrosion, atomic hydrogen is produced and can diffuse into the metal, accumulating and creating internal pressure that leads to blister formation.

Discussion
ahmadmmOption: B

Blistering only results from hydrogen generated by corrosion, not from hydrogen gas in the process stream.