Fire sprinklers
Permit application for contractors
We will send you a notice that you can begin work after we receive your plans, permit application and permit fees. This authorization is issued by email and will serve as confirmation that the plans have been accepted for review. A copy of the authorization letter should be kept on the job site.
What is the permit for and why do I need it?
This authorization allows fire protection contractors to initiate work pending the review of the plans, hydraulic calculations, and permit fees. This authorization is contingent upon correcting any deficiencies noted in the plan review process or as a result of any inspections conducted.
Helpful information
Taking the exam and becoming certified
How do fire sprinklers work?
The sprinkler triggers
The typical sprinkler consists of a plug held in place by a trigger mechanism. The most common type of trigger is a glass ampule filled with a glycerin-based liquid that expands when heated.
The liquid expands
This liquid is designed to expand and break the tube at a certain temperature. The most common are designed to break at 155 degrees. In the average sized room, a 5mm diameter ampule will usually break in about one to one and a half minutes from contact with a heat source. Ampules as thin as 1mm are manufactured for a faster response time.
The plug is forced out
The plug is forced out by the pressurized water behind it and deflected away by a beveled edge. The water sprays over the deflector plate which is designed to distribute it in an even pattern. Water will continue to flow until the main valve is shut off.
How does a sprinkler put out a fire?
Hot air heats up the sprinkler
Even a small smoldering fire acts like a heat engine as it steadily increases the air temperature directly above it. The hot air fans out across the ceiling, heating up the nearest sprinkler.
Sprinkler trips and water is released
As soon as the trigger mechanism is heated to the required temperature, it trips and the water is released. The immediate cooling of the heat source usually prevents other sprinklers from activating. Often, one or two sprinklers are enough to control a fire.
Training
Sprinkler saves
We are working with the Minnesota Chapter of the National Fire Sprinkler Association to collect information on sprinkler success stories or "sprinkler saves." Many of these incidents have some interesting facts that cannot be completely captured on standard fire reports.
If your fire department responds on a sprinkler activation that might be of interest to others, we encourage you to fill out this form and email it back to the email addresses shown on the form.
Questions?
Email us your fire sprinkler questions.
Visit the Home Fire Sprinkler Coalition Website for details about installing home fire sprinkler systems, how they work, why they provide affordable protection and answers to common myths and misconceptions about their operation.