It’s nearly winter again, and prepping for the cold typically includes testing antifreeze in wet fire sprinkler systems. The typical process for inspecting wet fire sprinkler systems involves:
It’s been 10 years since NFPA guidelines specified that site-mixed, unlisted antifreeze was no longer an approved option for wet systems. Because a listed alternative wasn’t yet widely available, new systems were almost exclusively designed as a dry system.
Because the primary purpose of antifreeze is to protect sprinkler systems from cold, contractors tend to only consider the minimum use temperature when selecting a listed antifreeze.
NFPA standards require all antifreeze fire sprinkler systems to switch to a listed antifreeze by September 30, 2022. These standards help ensure that an antifreeze system performs reliably in a fire and saves more lives, rather than contributing to fire as unlisted fluids can.
When installing listed antifreeze, the manufacturer’s installation guide is the final word. But talking with installers who have already started switching their clients to a listed product has revealed three installation tips that you won’t find in the official installation guide.
A UL-listed, factory-premixed antifreeze – like freezemaster™ antifreeze – will soon be the new normal for sprinkler systems needing seasonal freeze protection. This new normal requires different installation and maintenance than building owners and ITM contractors are used to with traditional antifreezes. Not taking these differences into account significantly shortens the life of listed antifreeze.
Before July 2021, a listed antifreeze approved for use in Ordinary Hazard 1 & 2 sprinkler systems larger than 40 gallons did not exist, even though many of these buildings require a system with significantly more antifreeze. This limitation made it difficult and expensive for antifreeze-based fire sprinkler systems in larger applications to maintain compliance with NFPA requirements.
Planning for freezing temperatures during the sweltering summer might not be the first thing on anyone’s to-do list in the fire sector. But in the case of sprinkler system freeze protection, 2021 is the year it should be. Advance planning, insights from the field and a broad perspective on where winterizing is needed will be useful to prepare for safe, effective freeze protection in sprinklered applications this winter and next.
Fire sprinkler systems can be prone to a specific category of corrosion plaguing the industry known as microbiologically influenced corrosion, or MIC. According to the FM Global report “Corrosion and Corrosion Mitigation in Fire Protection Systems,” MIC is responsible for 10-30% of corrosion in all piping systems in the U.S.