Fundamentals of MIC in Water-Based Fire Protection Sprinkler Systems
Abstract — Mechanisms for the occurrence of microbiologically influenced corrosion (MIC) in water-based fire protection sprinkler systems (FPS) are presented. Various methods proposed for the prevention and treatment of MIC in FPS are also discussed.
Kochelek says “The goal of dry pipe nitrogen inerting (DPNI) in dry and preaction fire sprinkler systems is to first, purge the oxygen oxygen-rich air from the piping, and second, to eliminate the future introduction of oxygen gas into the system piping. The goal is NOT to prevent all forms of corrosion.”
Abstract: Nitrogen “inerting” is an important component of a corrosion control program in dry and pre-action fire protection systems (FPS). However, it cannot prevent all forms of corrosion all of the time, for reasons discussed in this article.
Section 24.1.5 “Water Supply Treatment” has been revised and includes important changes that affect how corrosion in FPS are tested for and treated. Here are the key changes and the authors’ discussion of each issue.
First, as the investigator who first coined the term microbiologically influenced corrosion (MIC) and defined it as “any form of corrosion which is influenced by the presence and/ or activities of microorganisms” (ref.1) I am disturbed by the notion presented by some (e.g. Potter video on MIC) that microbes only affect pre-existing corrosion sites.