A Beginner’s Guide: 5 Types of Fire Sprinkler Systems

In the war against accidental fires, fire sprinkler systems are your most reliable, responsive, and resilient soldiers on the front lines.

Ready to suit up and save your commercial establishment from harm in a matter of seconds, these protective measures use their most trusted weapon of choice — water — to stop a minor mishap from becoming a lost battle.

If you own and operate a business (or plan to), knowing your options for a fire sprinkler system and choosing the best one for your building can keep flame damage low and operational success high.

Types of Fire Sprinkler Systems to Know

Wet pipe sprinkler system

Undoubtedly the most popular option, wet pipe sprinkler systems are cost-efficient, fast-acting, and incredibly effective.

These sprinkler systems constantly hold water in their lines, ready to activate seconds after a fire is detected. Once heat makes its way up to the ceiling near the wet pipe fire sprinklers, the core of the sprinkler head bursts, discharging water to the affected area.

With wet pipe sprinkler systems, not all sprinkler heads in your business are activated at one time. Only those exposed to heat and fire will discharge, helping to minimize the spread and damage of flames.

The only downside of wet pipe sprinkler systems is they can be prone to freezing issues. As such, all parts of the building where this fire protection unit is installed should be conditioned to at least 40 degrees Fahrenheit to prevent fire sprinkler system pipes from freezing.

Dry pipe sprinkler system

Dry pipe sprinkler systems are similar to wet pipe sprinklers — the only difference being that their piping does not store water 100% of the time. Instead, water in dry pipe sprinkler systems is kept behind a dry pipe valve, away from the sprinkler heads.

Just like in wet pipe systems, the fusible link or glass bulb of dry pipe systems breaks when the ceiling temperature becomes too hot. However, these automatic fire sprinkler systems do not release water immediately since the piping is not filled. As opposed to automatic water, the sprinkler head releases air, resulting in a drop of pressure that forces open the dry pipe valve to fill the sprinkler piping.

Once the piping is full, water will start flowing from the open sprinkler head to alleviate fire damage. Because dry pipe sprinkler systems are smaller than other types, the amount of time it takes to deliver water to the impacted area is reduced.

Dry pipe sprinkler systems are suitable in areas where you cannot guarantee high enough temperatures to prevent pipes from freezing and bursting. Nonetheless, at least one section of the building where the dry pipe is placed and the water comes in must have hot enough temperatures to avoid freezing.

Preaction sprinkler system

Preaction sprinkler systems are among the most complicated types since they’re a combination of wet and dry sprinkler units. In a preaction sprinkler system, water is not filled in the pipe until a fire is detected — like in a dry pipe system — yet the response time is fast, akin to a standard wet pipe system.

There are three types of preaction systems that may work for your business, including:

• Non-interlock systems
• Single interlock systems
• Double interlock systems

The main difference between these preaction sprinkler systems lies in the specific event(s) that must happen to trigger the release of water into the system.

A non-interlock preaction system releases water into the sprinkler system following the operation of smoke detector devices or automatic sprinklers. In contrast, a single interlock preaction unit, working like a dry pipe system, admits water to the sprinkler piping — but only after the operation of a smoke detector or fire alarm. Double interlock preaction systems require both the sprinklers and smoke detectors to activate before they’re able to respond quickly.

Preaction water sprinkler systems are ideal in places with water-sensitive items, such as computer rooms and museums, to minimize fire damage.

Deluge sprinkler system

Because they use the same type of detection for operation, deluge sprinkler systems are most similar to preaction systems.

However, the main differences between the two are that deluge systems have open sprinkler heads or nozzles and unpressurized dry piping. Directly connected to a water supply, these systems have a valve to keep water from the sprinkler piping until another type of detection system is operated, such as a heat or smoke detection unit.

Once these fire detection devices go to work, the deluge valve opens to admit water to the piping. At the same time, water will flow from all individual sprinkler heads or nozzles instead of just one head, a common feature of other system types.

Deluge sprinkler systems are ideal where fire damage is a primary concern, including high-rise buildings, power plants, and warehouses.

Standpipe system

Suitable for large area floor buildings, standpipe systems consist of a series of pipes that connect a water supply to hose connections. Essentially an extension of a fire hydrant, this system type has one main purpose: to provide fast-acting, pre-piped water distribution to building occupants or the fire department in an emergency.

According to the National Fire Protection Association, there are three different types of standpipe systems, including:

• Class I: Must provide a 2.5-inch hose connection that matches the hose thread used by the fire department. This class has no hose attached and is primarily required in buildings with more than three stories.
• Class II: Must provide 1.5-inch hose stations to supply water to trained personnel or the fire department during an emergency. This class is often found in cabinets with 100 feet of hose.
• Class III: Must provide 1.5-inch hose stations to supply water to trained personnel and a 2.5-inch hose connection to supply a greater amount of water to fire departments and other officials trained in more intense fires.

Though standpipe systems may not deploy water flow from a ceiling sprinkle head, they are a reliable fire protective measure and work hand-in-hand with each type of sprinkler system.

Find the Right Fire Sprinkler System for Your Business

While there are many benefits to having a reliable fire sprinkler system, not all types will work for your building, so it’s important to do your research and review any relevant fire safety regulations before setting up shop.

At Kistler O’Brien Fire Protection, we specialize in inspecting, installing, repairing, and maintaining fire sprinkler systems for businesses across Pennsylvania, New Jersey, and Delaware. With 300 years of combined staff experience, our team comprises industry-certified specialists that not only help keep you in compliance but also protect your people and property from fire devastation.

To learn more about how our fire sprinkler services work to secure your business, contact us today.