Protect Your Sprinkler System From Freezing In Cold Weather.

damaged standpipe system due to freeze up

With the cold weather quickly approaching, many of our customers are concerned that their water based fire protection systems may freeze in areas that are not heated. They asked how they can prevent their sprinkler and standpipe systems from freezing.

Fortunately, for most buildings the solution is simple……Annual Winterization Service. 

Annual winterization is the process of preparing your sprinkler system for cold months. This service varies with each building but typically involves turning on heat tracing systems, testing heat tracing for proper operation, draining low points and drum drips, inspecting insulation wrapped pipes for breaches or damage to insulation, etc.

Unfortunately, some buildings may not have existing freeze protection measures in place. For buildings that don’t have these in place we recommend self regulating heat trace systems with insulation be installed.

How does heat trace work?

Heating cable maintains the temperature of stagnant fluid by replacing the heat lost through the thermal insulation (shown above).

Wet-Pipe Fire Sprinkler

Wet-pipe sprinkler systems are filled with water and are highly susceptible to freezing when they’re exposed to the cold. Unfortunately, simply setting the temperature in a facility to 70°F doesn’t completely prevent a fire sprinkler freeze up. Facility managers need to monitor buildings for open windows or doors that expose sprinkler systems to cold temperatures. Some other ways to prevent fire protection system freeze-ups include:

  • Maintain 40°F temperature throughout the facility
  • Insulate pipes subject to the cold
  • Check fire sprinkler systems regularly during freezing temperatures

Dry-Pipe Fire Sprinkler

Dry-pipe systems don’t remain completely dry, despite what their name might suggest. Over time, water and condensation will build up in the system and flow to the low point drains and drum drips. You can easily avoid costly repairs by emptying these drains before the onset of cold weather. Also, verify that the dry-pipe’s compressor is in proper working condition. If the air pressure decreases, then it will trip the valves and allow water into the system. Lastly, ensure all the dry-pipe systems are set to each manufacturer’s air pressure ratio specifications.

  • Empty low point drains and drum drips
  • Ensure valve room is properly heated or systems are protected from freezing
  • Ensure low temperature monitors are operating as intended or if you don’t have this feature consider adding it
  • Evaluate air compressor’s working condition
  • Check air pressure ratio setting

Fire Pumps

Fire pumps provide the water pressure that fire sprinklers need during a fire. Freeze-ups in either of these systems can be detrimental in an emergency. Fortunately, you can easily prevent a fire pump freeze up by draining the test header after an annual fire pump test or other uses. This will prevent trapped water from freezing and splitting the test header valves and piping.

  • Drain test header after annual fire pump test and after each use
  • Maintain at least 40°F temperature in pump room
  • Maintain at least 70°F in pump room for diesel pumps without engine heaters

Fire Department Connection

Since the FDC is located on the exterior of a building it is subject to extreme weather conditions and temperatures. This can take a toll on its internal components. This could also result in an inability of responding fire departments to connect to this system to provide adequate water supply to the building. Check your fire sprinkler service records and make sure that the auto ball drip passed inspection. Also check that the required 4′ frost break is present. If there’s a deficiency, make sure you schedule the repair immediately. Otherwise, the water sits in the connection and can freeze. Also, ensure that your service provider performs an internal inspection every 5 years or if the FDC caps go missing, it may also be necessary to have the connection flushed of debris. An impaired check valve allows water to flow through the FDC. This has the potential to damage the entire assembly.

  • Functional auto ball drip
  • Internal inspection every 5 years or if FDC caps go missing
  • Ensure there is a 4′ frost break
  • Ensure there is no residual or pressurized water in the system


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