Severe Graphitic Corrosion in Cast Iron Drain Lines in a Health Care Facility
Environment: Vertical and horizontal waste water drain line located in a health care facility. Pipes were located in both finished walls, and in the crawl space.
Material: Cast iron drain lines are to conform to ASTM A888, the analyzed pipe did not conform to these specifications.
Installation Date: approx. 1983
Service Life: approx. 23 years
Mode of Failure: Severe graphitic corrosion, and cracking due to the use of a cast iron material which did not meet specifications for this use.
Findings: The drain line system contained multiple longitudinal and transverse cracks in the cast iron piping. In addition, sever graphitic corrosion had reduced the wall thickness of piping in some locations to 1/16-inch or less, creating holes and leak sites, in some locations, appearing as ‘carbunkle’ leak sites.