The system has the functions of automatic detection, alarm and water spraying, and can also be used in combination with automatic fire alarm device. Because its water supply pipes and nozzles are always filled with pressurized water, it is called wet automatic sprinkler system. The system consists of closed sprinkler, pipeline system, wet alarm valve, alarm device and water supply facilities.
Working principle: In case of fire, the flame or high-temperature airflow makes the heat-sensitive element of the closed sprinkler act, and the sprinkler is turned on to extinguish the fire by spraying water. At this point, the water in the pipe network changes from static to flowing, which makes the water flow indicator act to send out an electrical signal, indicating that a certain area on the alarm controller is spraying water. Due to the continuous water spraying and pressure relief when the nozzle is opened, the upper water pressure of the wet alarm valve is lower than the lower water pressure. Under the action of pressure difference, the originally closed wet alarm valve will automatically open, and the pressure water will flow to the fire pipe network through the alarm valve, at the same time, the channel leading to the hydraulic alarm bell will be opened, and the water flow will impact the hydraulic alarm bell and send out an audible alarm signal. According to the alarm signal of water flow indicator or pressure switch, the control center automatically starts the fire pump to pressurize and supply water to the system, so as to achieve the purpose of continuous automatic water spraying.
2. Pre-acting automatic sprinkler system
Pre-action systems are generally installed in places where water is needed for fire fighting, but non-fire water is absolutely not allowed to run, such as libraries, archives and computer rooms.
The system consists of fire detection and alarm system, closed sprinkler, pre-action valve, inflation equipment, pipeline system and control components.
The characteristics of pre-action automatic sprinkler system are as follows: it has the advantage of dry automatic sprinkler system without water at ordinary times. The pipe network behind the pre-action valve is usually not filled with water, but with pressurized air or nitrogen, or the main pipeline. Only when a fire happens, the fire detection system automatically opens the pre-action valve, so that the pipeline is filled with water and becomes a wet system, which can avoid water damage caused by system damage; At the same time, there is no disadvantage that the dry automatic sprinkler system must wait until the nozzle is exhausted to extinguish the fire, which delays the spraying time of the nozzle; In addition, the system also has an early warning device, which can give an alarm in time before the sprinkler moves, so as to organize the fighting as soon as possible. The system closely combines the wet automatic sprinkler system with electronic alarm technology and automation technology, making the system more perfect, safe and reliable, thus expanding the application scope of the system.