Sprinkler systems

28 June 2023

Sprinkler systems have been around since the late 19th century and are a simple and active component of a commercial or domestic building’s fire protection system.

Fire sprinkler in ceiling of building

The system consists of a water supply, a water distribution piping system and sprinkler heads. The sprinkler discharges water automatically when heat from a fire is detected. They are not triggered by smoke. Sprinklers help control and may often extinguish a fire. Therefore, sprinkler systems are considered both a fire detection and suppression system.

The types of fire sprinkler system most often found are either wet pipe or dry pipe. Other types of sprinkler systems include deluge systems and pre-action systems.

Wet pipe systems

Wet pipe systems are the most common type of sprinkler system found in residential buildings. Here cold water is stored under pressure in the network of pipes and released immediately by sprinkler heads when a predetermined temperature is reached.

Dry pipe systems

Dry pipe sprinkler systems take slightly longer to activate. They are found in buildings that may be either unheated or unoccupied and where pipes may freeze and burst. Either nitrogen gas or pressurised air is stored in the pipes, connected to a water storage tank or main. On activation by a fire, the air leaks out of the pipes, causing the water to flow through the pipes to the sprinkler heads.

The water supply on which a sprinkler system depends may be derived from, either the mains, a water tank in the building or in some cases a pond or reservoir.

Deluge systems

Deluge systems are often used in areas where rapid fire damage is a major concern, such as warehouse loading bays and high-rise buildings. In these systems, the nozzle is always open. They are triggered by an alarm that opens a water release valve.

Pre-action sprinklers

Pre-action sprinklers are a combination of wet and dry pipe systems, which are used in areas at high-risk of water damage. Water is not stored in the pipes until a fire is detected, when it is released to the sprinkler heads.

The major benefit of a fire sprinkler system is that it will protect both the property in which it is installed and the people working or living within it.

For more information on managing risks associated with sprinkler systems we have developed a suite of guidance notes below: