Corrosion Solutions MIC Corrosion
Microbiologically Influenced Corrosion (MIC) in Fire Sprinkler Systems
Corrosion (both oxygen and microbiologically influenced) is well founded in fire sprinkler systems. Wet dry and preaction fire sprinkler systems have seen an increase in corrosion since the late 1990's. Several factors may be responsible such as changes in the Clean Drinking Water Act, use of lower grade materials and material selection. Corrosion monitoring and mitigation is needed to forecast and eliminate such costly corrosion. Testing of water, sludge and tubercles from fire sprinkler systems is required to fulfill certain areas of NFPA 13 and 25.
U.S. Fire Administration MIC Report
Microbiologically Influenced Corrosion (MIC) has recently been discovered as a contributing force in corrosion of wet, dry and preaction fire sprinkler systems. Symptoms of MIC, including pinhole leaks, smelly water, black water and tubercles were long considered to be "normal" for fire sprinkler systems and to be part of the industry. These corrosive symptoms have increased in the last few years and further investigation has discovered that the forces of MIC are present. There are several theories as to the "why" the increase in microbiologically influenced corrosion (MIC) is present in fire sprinkler systems and the popularity of lower schedule piping has increased the awareness as the affects are seen sooner than with higher scheduled piping. The National Fire Protection Agency (NFPA) is addressing the MIC problem with changes in NFPA 13 & 25.
Oxygen corrosion is also prevalent in fire sprinkler systems and evidence of high corrosion exist especially at the air/water interface at the high points of fire sprinkler systems. All water contains entrapped air and this air migrates to the top of fire sprinkler systems. Thus, creating an air water interface. Potter Corrosion Solutions has the solution for this problem with an air vent (Model PAAR stock #1030000), which "burps" the system.