Types of Fire Sprinkler Systems We Install

Wet fire sprinklers (or wet pipe sprinklers) utilize automatic sprinkler heads that are attached to a piping system connected to a water supply. When the sprinkler system is activated by the heat of a fire, water is released from the sprinkler heads. 

A dry pipe sprinkler system is one in which pipes are filled with pressurized air or nitrogen, rather than water. This air holds a remote valve, known as a dry pipe valve, in a closed position. Located in a heated space, the dry-pipe valve prevents water from entering the pipe until a fire causes one or more sprinklers to operate. Once this happens, the air escapes and the dry pipe valve releases. Water then enters the pipe, flowing through open sprinklers onto the fire. 

Pre-action fire sprinkler systems employ the basic concept of a dry pipe system in that water is not normally contained within the pipes. The difference, however, is that water is held from piping by an electrically operated valve, known as a pre-action valve. Valve operation is controlled by independent flame, heat, or smoke detection.

Two separate events must happen to initiate sprinkler discharge. First, the detection system must identify a developing fire and then open the pre-action valve. This allows water to flow into system piping, which effectively creates a wet pipe sprinkler system. Second, individual sprinkler heads must release to permit water flow onto the fire.

A deluge system is similar to a pre-action system except the sprinkler heads are open and the pipe is not pressurized with air. Deluge systems are connected to a water supply through a deluge valve that is opened by the operation of a smoke or heat detection system. The detection system is installed in the same area as the sprinklers. When the detection system is activated water discharges through all of the sprinkler heads in the system. Deluge systems are used in places that are considered high hazard areas such as power plants, aircraft hangars and chemical storage or processing facilities. Deluge systems are needed where high velocity suppression is necessary to prevent fire spread. 

Low Expansion foam offers a 5:1 expansion rate, making it the foam system of choice to protect large and hazardous facilities, including; petro-chemical tank farms, loading docks, processing areas and refineries and liquefied natural gas storage. 

With an expansion rate of 500:1, High Expansion foam systems are more suitable to protect less common three-dimensional hazardous facilities including; warehouses, conveyors, aircraft hangars and tunnels.

As such, High Expansion foam is measured by volume output rather than application rate, as is typical of low expansion foams.