How it Works: Fire Sprinkler Systems

Nov 20, 2019 | Sprinkler Systems

Sprinkler systems are an important part of protection from fires. A fire sprinkler system can prevent property damage and reduce the risk of injury to workers, customers, or tenants. But how exactly does a fire sprinkler system work? Understanding how a fire sprinkler system works can help you determine the right kind of system for your property.


There is a common misconception that sprinklers are triggered by smoke. Fire sprinkler systems have strategically placed sprinkler heads with glass bulbs containing a glycerin-based liquid. Sprinkler systems detect a fire through rising temperatures. As the temperature at the sprinkler head rises to between 135 to 165 degrees Fahrenheit, the liquid inside the glass bulb expands and breaks the glass, thus activating the sprinkler head. There are various colors of liquid in these glass components, each indicating a different threshold of heat required to break the glass.

fire sprinkler system Detection

Fire sprinkler systems Detection


Depending on the type of sprinkler system, the method of sprinkler activation can vary. Once the glass bulb breaks, the sprinkler head releases water. However, the way water is stored and is delivered through pipes depends on the type of fire sprinkler system. Wet pipe systems store water in the pipes and release it immediately when the trigger breaks. Dry pipe systems store water behind a valve that needs to be released before the water can flow through the pipes and out of the sprinkler head. A pre-action sprinkler is like a dry pipe system except for the valve is controlled by an electronic device. The only exception is the deluge sprinkler system that is not activated by heat at all. Instead, a fire alarm releases the water and a valve must be manually closed to stop the flow of water.

Pressurized Sprinkling

Wet pipe, dry pipe, and pre-action sprinklers all use pressurized air. In wet pipe sprinklers, pressure in the pipes ensures the water is delivered quickly. In dry pipe and pre-action sprinkler systems, pressurized air is used to fill the pipes instead of water filling the pipes. Once the air is released, due to a fire being detected, the water then flows through the pipes.

Post Fire

It is a myth that once a fire is detected all fire sprinklers go off. fire sprinkler system detects rising temperatures at each individual sprinkler head and goes off only when the fire reaches that sprinkler. If you require a sprinkler system where all the sprinkler heads go off at the same time, then you need a deluge sprinkler system. Deluge sprinkler systems release water from every sprinkler head once a fire alarm goes off and are used in facilities with flammable or combustible liquids where the threat of fire is extremely high. Keystone Fire Protection Co. offers a foam sprinkler system for these high-risk environments which smothers, cools, and extinguishes fires. Other fire sprinkler systems have minimal clean-up and cause little damage due to the localized response such as the Hi-Fog Water Mist system offered by Keystone Fire Protection Co.

Fire Sprinkler System Maintenance, Testing, and Inspection

Fire sprinkler systems should be inspected and tested according to NFPA 25. Weekly or monthly, gauges should be inspected. Quarterly, alarm devices and control valves should be inspected. Bracings, pipes, fittings, and signings should be inspected annually. Every five years, an internal inspection is required. Tests of mechanical devices should happen quarterly. Switch type devices should be tested every six months. Every year, full testing and tagging should include water flow, fire pump, antifreeze concentration, and alarm tests. Not only will Keystone Fire Protection Co. install the correct sprinkler system for your property, but we will also perform regular inspections, testing, and maintenance as needed. In order for you to be fully protected, your fire sprinkler system must be working properly. Keystone fire sprinkler system technicians are experts in good standing with the American Fire Sprinkler Association and provide quarterly or yearly inspections at frequencies that comply with NFPA standards. These inspections are reported to you and the Authority Having Jurisdiction, and they are available at all times on each customer’s Keystone Client Connect web portal account. Highly trained staff are also able to diagnose and repair problems with your fire sprinkler system. These qualified individuals check your fire sprinkler system without disrupting you or your business. Contact Keystone Fire Protection Co. today for a quote or with questions related to fire sprinkler system inspections, testing, or maintenance.


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