What Causes a Fire Sprinkler to Activate? – Understanding the Triggers

Fire sprinkler spraying water on fire

As you may already know, fire sprinkler systems are incredibly useful for fire safety. When activated, fire protection systems can quickly and effectively suppress a fire, limiting property damage and protecting lives.

While there is no doubting that automatic sprinklers are incredibly important, many people are unsure what causes a fire sprinkler to activate. This is where we can help!

We will explain in detail what causes a fire sprinkler to activate, so you can better understand how these fire suppression systems are designed to work.

We will also cover some reasons for an accidental fire sprinkler activation and what you can do about it.

So, let’s get started!

How Fire Sprinklers Are Supposed to Be Activated

Red pipe and head of fire sprinkler system

While there are other ways that a fire sprinkler system can be activated accidentally, most systems are designed to be activated in two ways:

1. Heat Detection

While many people assume that fire sprinkler systems are triggered by smoke detection, they are activated by heat. All modern fire sprinkler systems rely on heat-sensitive elements to act as triggers. Depending on the design of the fire sprinkler, it will either use a fusible link or a series of glass bulbs.

Those that rely on the fusible link design feature a metal alloy with a specific melting point. According to the National Fire Protection Association in the US, typically, this will be around 135°F to 170°F. When the air surrounding the fusible link reaches this temperature, the metal alloy will melt, triggering the sprinkler head to release the water supply in all directions.

Other fire sprinkler systems use a glass bulb within each sprinkler. These bulbs are filled with a liquid that expands when heated to a certain temperature. When this occurs, the glass will break, which activates the sprinkler head.

Thanks to these designs, each fire sprinkler head operates independently. This prevents water damage in areas that are unaffected by fire.

2.     Manual Activation

Most fire sprinkler systems can also be activated manually through a control panel. If the heat does not cause the sprinklers to activate and release water flow, the option for manual activation can be incredibly important.

Some more advanced commercial fire sprinkler systems can be linked digitally to the fire alarm system. These tend to be less common in public buildings, as the water damage caused by a fire sprinkler system activated due to an accidental or malicious fire alarm pull would be too great of a risk.

Can Fire Sprinklers Misfire?

Close up of fire sprinkler head on ceiling of building

While it is true that most fire sprinkler systems are reliable, there are ways that they can be activated unintentionally or at inappropriate times. When accidental fire sprinkler activation occurs, the water damage caused by the misfired sprinkler can be costly and destructive.

To help you determine if your fire suppression system is at risk of unintentional activation, here are the leading causes of misfires.

High Temperatures Unrelated to a Fire

Since fire sprinkler heads are activated by heat, high temperatures unrelated to a fire could trigger a misfire. In most cases, this is due to the sprinkler head’s proximity to a heat source, as the temperature needs to be very high to melt the fusible link or shatter the glass bulb.

Avoid positioning sprinkler heads near steam pipes, heating vents, cooking appliances, or machinery that generates significant heat.

Physical Impact

If a sprinkler head is hit with enough force, the fusible link or glass bulb could become damaged, triggering a sprinkler misfire. You should always avoid positioning equipment and inventory near fire sprinkler heads.

Not only would doing so increase the likelihood that the sprinkler could be hit, but it could also block water from reaching a fire if needed to suppress a fire.

Installing fire sprinkler head guards is another way to prevent misfires due to physical impact.

Corrosion and Lack of Maintenance

Like any fire suppression system that involves pressurized water, fire sprinklers can rust and corrode over time. When this happens, it can cause failures and unintended activations.

Various defects can trigger a fire sprinkler to activate at an inappropriate time. To avoid these issues, it is crucial to inspect your automatic sprinkler system at regular intervals, as well as perform the manufacturer-recommended maintenance requirements.

Read A Guide to Maintaining Your Commercial Fire Sprinkler System for more information. This guide is packed with helpful information and a breakdown of monthly and annual maintenance requirements.

What Should You Do if Your Fire Sprinkler Misfires or Accidentally Activates?

While avoiding the primary causes of accidental activations and misfires is incredibly important, fire protection systems can still release water at inappropriate times. Unfortunately, even a single sprinkler head can release 60 gallons of water per minute, which can cause significant water damage.

Rather than waiting around for the fire department’s arrival, give yourself the ability to shut off a fire sprinkler in seconds by looking at the Shutgun.

The Shutgun is an easy-to-use, handheld tool that can shut off a fire sprinkler head in seconds. Its one-hand operation means a single person can shut off a sprinkler from a ladder without training.

Learn more and order your own Shutgun by clicking the following link: Get My Shutgun!

Final Words

While a misfiring fire sprinkler can be incredibly damaging, especially if you do not have access to a shut-off tool, like the Shutgun, it is essential that you still have a fully-functioning fire sprinkler system to protect your business, employees, and more.

To prevent accidental activations and to know that you can rely on your system when the worst happens, perform regular inspections, tests, and maintenance on your system. Remember, water damage can be costly but never as dangerous and destructive as large-scale fire damage.

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