What type of fire sprinkler system uses both water and gas to extinguish a fire?

A pre-action sprinkler system is designed to use both water and gas to extinguish a fire. This system typically consists of a two-step activation process. First, a fire detection element, such as a smoke or heat detector, must activate before the system allows water to flow. Once the detection device signals a fire, the system releases water into the piping network. However, the pre-action system is often used in situations where accidental water discharge must be avoided – for example, in areas with sensitive equipment.

The initial element of gas within this system might refer to the use of nitrogen or another gas to pressurize the water supply lines or to help enhance the detection capabilities of the system. The combination of gas and water offers the benefits of reliable fire suppression while reducing the risk of water damage from false alarms.

This system is particularly effective for protecting environments where water can cause significant damage, combining quick action against fire with a safeguarded approach to avoid unnecessary water release.