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How to prevent your sprinkler system from freezing

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Apr 19, 2019

Installation of a Dry Sprinkler
Dry sprinklers are so named because there isn’t any water in the pipe barrel until the system needs to operate. Instead, the dry pipe sprinkler features a barrel with a seal at the connection point to the wet pipe sprinkler system. Water does not enter the barrel until the sprinkler operates which releases the seal. This keeps the part exposed to the freezing conditions dry and unable to freeze. Although this process is nothing new, we are discovering that some installations do not meet the minimum code requirements or manufacturer’s installation guidelines.

With dry type sprinklers, there are two main concerns with installation. The first area of concern is the length of the barrel and the second is the distance between the face of the fitting and the inside surface of the exterior wall or insulation, whichever is closer to the fitting.

Insulation Matters
The second means of preventing a wet pipe sprinkler system from freezing is by insulating the sprinkler pipe. Using insulation over the sprinkler pipe traps the flow of warm from the adjacent spaces.

When the proposed insulation installation method is not one of those prescribed by the NFPA, heat loss calculations are required to be performed by a professional engineer to verify that the system will not freeze.

There are nine different NFPA prescribed approaches dealing with sprinkler freeze protection. Although the requirements for preventing a sprinkler system from freezing are clear, some designs and installations are overlooked, and you could end footing a repair bill that could be avoided. Identifying and correcting deficiencies prior to the completion of construction can potentially save you thousands of dollars in future repairs.

What’s been your experience with wet pipe fire sprinkler systems? Shoot us a note at info@jensenhughes.com or tweet us @jensenhughes