Cathodic Protection/Corrosion Control

Introduction Review online course content. Review questions.

Workshop Objectives To provide discussion, demonstrations, and hands-on activities that will enable you to: Define the corrosion process Explain the causes of corrosion Identify types of corrosion. Define: Stress Corrosion Cracking (SCC) Selective Seam Corrosion (SSC)  List locations to inspect Identify elements to look for during an inspection Explain how to handle corroded materials

Corrosion The conditions that cause corrosion Environmental factors contributing to corrosion Determining the extent of deterioration “Real world” scenarios - 

Stress Corrosion Cracking (SCC) Selective Seam Corrosion (SSC) Image Retrieved July 2013 Stress corrosion cracking (SCC) -http://www.met-tech.com/preheater-tube-failure.html http://readconsultingblog.blogspot.com/2011/10/brass-plumbing-failure-analysis-stress.html Selective Seam Corrosion (SSC) - http://www.panteraplace.com/Tech%20Info/Green%20close%20up%20rust%20out%20rocker%20to%20floor%20seam.jpg

Corrosion Types Anti corrosion coatings Atmospheric Localized (pitting or crevices) Generalized Galvanic Microbiological Graphite Flow-Assisted Anti corrosion coatings Paint Tape Insulation

Inspections-Locations Appropriate Inspection Intervals (as required by the Code of Federal Regulations) Locations to inspect Above grade Where soil and air meet At bolted connections At pipe supports In splash zones Where pipe spans water Under thermal insulation Under disbonded coating At deck penetrations

Inspections What to look for during an inspection Rust Cracking, flaking or chalking Thin or rough spots Discolored or mottled surfaces Holes, cuts or gouges Wrinkled or disbonded coating (difficult to detect) Cracked, chipped, flaking or peeling paint Determine the extent of deterioration Local inspection standards Activity Worksheet #1

Sources Occupational Safety and Health Administration (OSHA) Compressed Gas Association (CGA) US Department of Transportation (FHWA) Code of Federal Regulations: §192.459 External corrosion control: Examination of buried pipeline when exposed. §192.479 Atmospheric corrosion control: General. §192.481 Atmospheric corrosion control: Monitoring. §195.569 Do I have to examine exposed portions of buried pipelines? §195.581 Which pipelines must I protect against atmospheric corrosion and what coating material may I use? §195.583 Atmospheric corrosion control: Monitoring. What must I do to monitor atmospheric corrosion control

Corrosion Performance Checklist Complete the Corrosion Performance Checklist Discuss completed checklists with entire class.

Open Discussion Questions Comments