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Winterizing Your Fire Sprinkler System


As the weather gets colder, it’s important to start thinking about winterizing your fire sprinkler system. Like the rest of your plumbing system, your sprinkler system can freeze if exposed to cold temperatures, even when filled with an antifreeze solution. Fortunately, there are ways to prevent your system from icing up no matter how cold it gets.

How to Protect Your Sprinkler System from Freezing

  • If your system is made of CPVC and is connected to a potable water supply, you should use an antifreeze solution of glycerine, not glycol. Using glycol-based antifreeze solutions creates a chemical environment that can damage CPVC pipes.
  • If your sprinkler system is connected to a potable water supply and made of a material other than CPVC, you can use a propylene glycol antifreeze solution.
  • All antifreeze solutions must be diluted with water. Pure antifreeze tends to thicken when it approaches 32 F.
  • Local building codes may require a backflow preventer if the sprinkler system is connected to a potable water supply.

It’s important to note that your fire sprinkler system must meet specific installation requirements in order to function properly. These installation requirements depend largely on site conditions, construction, and other system requirements. For example, the geometry of the piping system can be a problem since the heavier glycerine will settle into the lower pipes, leaving only water or a dilute solution in the upper pipes. This condition can be alleviated by using special piping arrangements, but may require draining and refilling procedures.

In order for the sprinkler system to function properly, it’s also important to have it tested according to certain procedures. Antifreeze tests include emptying the entire system into containers and adding concentrated liquid antifreeze as required to create the proper mixture. The solution can then be put back into the system.

The NFPA recommends drawing a sample of the solution two or three times during the freezing season to determine if the solution has weakened. If it has, the entire system must be emptied and recharged as previously described. Following these steps will help you avoid the unpleasant experience of freezing and bursting sprinkler pipes.

Remember, antifreeze by itself will not necessarily prevent sprinkler pipes from freezing. The system must be filled with the proper chemical, mixed in the proper solution, and installed in the proper manner. For more information about winterizing your fire sprinkler system or to schedule a fire sprinkler inspection, call Confires today!

Category: Fire Sprinklers