In recent years the cause of pinhole leaks in both wet and dry sprinkler system piping has become attributed to corrosion mechanisms including Microbiologically Influenced Corrosion (MIC). MIC is composed of specific bacteria, both aerobic and anaerobic, that can accelerate corrosion mechanisms leading to system failures in the form of pinhole leaks or corrosion product buildup to the point of obstructing the flow of water in the system piping. Because fire sprinkler systems are usually
designed as non-circulating, closed loop systems constructed of ferrous engineering materials in contact with untreated water, they can become ideal breeding grounds for bacteria where MIC can occur. Periodic system maintenance and tenant improvement work introduces fresh bacteria, oxygen and nutrients into the system and can aid the mechanisms associated with MIC. Using recently developed methods of chemically cleaning and treating new and existing fire protection systems can control corrosion problems leading to system failures.