A fire sprinkler system is a simple, but key, active component of a domestic or commercial building’s fire protection system.
Installed in ceilings or side walls, the system consists of a water supply, a water distribution piping system and sprinkler heads. The sprinkler discharges water automatically when a fire is detected, though it is not triggered by smoke. It controls or extinguishes the fire, so is both a fire detection and suppression system.
Fire sprinkler types
There are four main types of fire sprinkler system:
•Deluge • Pre-action • Dry pipe • Wet pipe
In a wet pipe fire sprinkler system, the most common type in residential buildings, cold water is stored under pressure in the pipes and is released immediately by sprinkler heads when the predetermined heat level is reached.
Dry pipe sprinkler systems take slightly longer to activate and are used in unheated/unoccupied buildings where pipes may freeze and burst. Nitrogen gas or pressurized 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.
Deluge sprinkler systems are typically 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.
The Operation of the Deluge Valve
The deluge valve is opened and closed via the only moving part of the valve: the special sealed reinforced rubber, regularly known as the diaphragm.
1. Closed state: the pressure (P1) behind the diaphragm is equal to the main pressure (P2) of the water flow. This leads to closing of the deluge valve.
2. Open state: through evacuation of water behind the diaphragm, the pressure is reduced. As a result, the pressure of the main water inlet causes the instantaneous opening of the valve and the flooding of water.
Pre-action sprinkler systems
Pre-action sprinkler systems are a combination of wet and dry pipe systems, typically used in areas at high-risk of water damage. Water is not stored in the pipes until a fire is detected, when the water is released to the sprinkler heads. The response time is as fast as a standard wet pipe sprinkler system. Automatic fire sprinkler systems are also available and are effective in large areas such as offices and shopping centers.
Water spray systems as defined in NFPA 15 can provide some of the most complex and challenging system designs encountered by fire protection professionals. The selection of the proper spray nozzle that achieves the coverage area and water density required for the hazard being protected is one of the most important steps necessary to ensure the successful operation of the system. water spray nozzles range consists of Full and Flat Cone Spray Nozzle.
Full Cone Spray Nozzle
Full cone nozzles produce medium- to large-size drops forming a solid cone-shaped spray pattern with a round impact area. The unique design features large flow passages to provide superior control and uniform distribution. The full cone spray pattern is ideal for washing, rinsing, cooling, dust control and fire protection.
Flat Cone Spray Nozzle
A flat fan spray nozzle serves the purpose of spraying onto a surface or an object moving in a transverse direction with respect to the direction of the jet, a typical example being the nozzles in a car washing tunnel.
A water mist system is a fire protection system which uses very fine water sprays (i.e., water mist). The small water droplets allow the water mist to control, suppress or extinguish fires by: cooling both the flame and surrounding gases by evaporation.
A fire hose reel is a first attack piece of fire-fighting equipment. It is designed to be used as a quick-response method by any member of the general public for fighting fires in their early stages. Hose Reels are suitable for Class A fires: Paper, Textiles, Wood, Most Plastics and Rubber. Do NOT use on electrical fires, remember water conducts electricity, so using a fire hose reel on it could lead to electrocution!
Fire Hose Reels are easy to use and provide a virtually unlimited supply of water, as they are connected to the mains water supply, and should extend for approximately 35 meters.
Fire Hose reels consist of a length of non-kinking tubing. They are permanently connected to a water supply and consist of a main turn on/off valve, a hose guide, and a hose with a nozzle. The control nozzle attached to the end of the hose enables the operator to control the direction and flow of water to the fire.