The two most commonly used systems are the wet fire sprinkler and the dry fire sprinkler systems.

While some are familiar with the terms, few actually understand their differences. But understanding what sets these two systems apart is important for knowing which system is best for your building.

Wet Fire Sprinklers

Wet fire sprinkler systems are by far the most common, simplest, and most affordable systems to install.

How They Work

A wet fire sprinkler system means that, at all times, the overhead fire sprinkler piping is filled with pressurized water. When a fire occurs and the heat activates the sprinklers, water immediately sprays from the activated sprinkler heads. 

Pros & Cons

There are numerous benefits to a wet pipe system. Their mechanisms are quite simple, meaning installation and maintenance is easy and affordable, and the system is more reliable. Furthermore, since the pressurized water is always filling the pipes, the water is there instantaneously when it’s needed.

The downside, however, is that it cannot be used in any structures where the temperatures will drop to 40° F or below due to freezing risks. An additional risk is that should the pipes develop a leak, there could be extensive property damage.

Dry Fire Sprinklers

A dry fire sprinkler system might not be what you think. It does not use dry chemicals to suppress a fire.

Rather, a dry fire sprinkler keeps pressurized air and/or nitrogen in the non-heated portions of the sprinkler pipes. This way, if and when temperatures drop below freezing, the pipes are not in danger of freezing.

How They Work

The way dry pipes work is the pressurized air or nitrogen holds a valve closed that separates the main piping from the water supply. In the event of a fire, when the heat activates the sprinkler head, the air pressure drops. Once it drops, the dry-pipe valve opens up and releases the water, which can then flow to the activated sprinkler head. 

Pros & Cons

The benefits of a dry pipe system are that they are ideal for use in structures where temperatures will reach freezing (such as parking garages, loading docks, walk-in refrigerators, etc).

However, because they require a constant, reliable air supply and special components, the system is significantly more complex to install and maintain, is costlier, and has far more design restrictions.

Furthermore, they will have up to a 60-second delay from when the sprinklers are initially triggered.

If you are concerned about the quality of your fire sprinklers or if you are unsure which type you have contact us at Ultra Fire Operations. We are experts at fire sprinkler inspection and can perform your regular inspections.