Abstract
The rapid adoption of sprinkler systems as fire safety measures in residential, commercial, and industrial buildings across Norway is driven by regulatory changes, such as TEK17 introduced in 2017, and heightened awareness of fire hazards. However, the integrity of these systems is increasingly threatened by microbiologically influenced corrosion (MIC), a complex mechanism caused by microbial activity.
MIC is well-documented and has long been associated with water distribution systems, oil and gas pipelines, and marine environments. Recent research indicates however its growing impact on water-filled systems like sprinklers, especially in stagnant or low-flow conditions. Zinc coatings, once used for corrosion protection, have been found to accelerate MIC, as zinc corrosion generates hydrogen gas, promoting bacterial growth and intensifying corrosion. - Despite withdrawing the approval of zinc-coated pipes due to hydrogen gas formation, millions remain in service, necessitating robust monitoring and controlled hydrogen gas release. Preventive measures like advanced water treatment and hydrogen pressure management are critical, though knowledge gaps persist regarding MIC's prevalence and causes in sprinkler systems.
This study investigates MIC by analysing corroded surfaces and microbial activity. While MIC-associated tubercles were observed, DNA analysis revealed only low microbial levels, highlighting the challenge of detecting microbiological activity in such systems. These findings emphasize the need for proactive measures, such as biocide treatments and improved installation practices, to ensure long-term system integrity.