How to Prevent MIC?

  In a wet fire sprinkler system, microbiologically influenced corrosion (MIC) and other forms of internal corrosion usually start from two things:

  1. Fabrication residues and debris left inside the pipe.
  2. Trapped air and oxygen at gas–water interfaces after the system is filled

  If these aren’t controlled, they can drive early corrosion, leaks, and pressure to shut valves – exactly what owners and contractors want to avoid.
  Our Corrosion (MIC) Prevention Solution is built to control both variables and to document performance over time. That’s why we can back it with a 15-year limited leak warranty for our pipe in qualified wet systems.

Three pillars of the solution:

(1) Clean-interior steel fire sprinkler pipe
  In typical wet systems, fabrication residues such as fines, mill scale, and cutting fluids can remain on pipe interiors. Once water is introduced, these residues provide surfaces and nutrients where biofilm can establish; under-deposit corrosion and MIC may then initiate.
   Our approach removes this variable: we supply clean-interior UL/cUL listed steel fire sprinkler pipe, removing fabrication residues and debris that can create biofilm starting points and going beyond the NFPA 13 intent of keeping debris out of the system. WPNI can only control corrosion that occurs after water flooding; the internal cleanliness of the steel pipe still determines how quickly corrosion starts and spreads. That’s why we focus so strongly on cleanliness.

(2) Low-oxygen handover (O₂ ≤ 2%):
  Trapped air leaves oxygen at gas–water interfaces, which drives early corrosion and creates more deposits. To control that, we combine:

  1. NFPA 13 air venting at high points, and
  2. Wet Pipe Nitrogen Inerting (WPNI) – supplied by Tyco, ECS, Potter, or equivalent – to displace oxygen with nitrogen.

  Acceptance is O₂ ≤ 2% at representative high points at handover, documented in the project handover package. This low-oxygen condition reduces the driving force for corrosion after the system is flooded and placed in service.

(3) Ongoing documentation and maintenance
  We do not claim sterilization—potable fill water isn’t sterile, and we don’t leave chemicals in the service water. Instead, the control method is:

  1. Cleanliness – start with clean-interior pipe.
  2. Oxygen management – achieve and maintain low oxygen in the system.
  3. Documentation – prove it over time.

The program requires:

  1. Annual oxygen spot checks, and
  2. Re-inerting after major water additions or significant modifications,

  combined with NFPA 25 inspection, testing, and maintenance to keep the system within the design envelope over time. Your qualified fire protection contractor maintains the system and the records (NFPA 25 reports, oxygen logs, re-inerting records) needed to keep the warranty in force.

Why this allows a 15-year limited leak warranty?

  Because the program is outcome-based—cleanliness + oxygen management + documentation—we can confidently offer a 15-year limited leak warranty to building owners for wet systems where qualified contractors install our clean-interior pipe, achieve low-oxygen handover, and maintain the system within the program requirements.

  In simple terms: we control the variables that drive MIC and internal corrosion, and we prove it over time. That’s why we are willing to stand behind our pipe with a long-term, owner-facing leak warranty.