Pre-action alarm system is a valve module that specially designed for fire protection system use. The system is a kind of control valves mainly consisted of deluge alarm valve and Wet system alarm valve which are concatenated up and down. The system is opened by using manual, mechanical and other ways together with close-type sprinkler, so as to make water flow into sprinkler system in one way automatically and start alarming simultaneously.
Working principle: In case of fire, the heat and smoke fire sensor will be firstly detecting the potential fire and then they send alarm signal to fire alarm controller or fire protection control center. Upon receiving the alarm signal, the fire alarm controller or fire protection control center will send command to switch on the solenoid pilot valve on deluge alarm valve which can be then actuated to open and fill water in fire protection pipeline, and then the water powered alarm starts to alarm. If the fire continues to develop, the glass bulb of the close-type sprinkler will break up to spray water and the pump begins operating automatically.
Application: The pre-action alarm valves system is equipped with close-type sprinkler, combining the technology of fire automatic detecting and alarming with the system of automatic sprinkler and fire extinguishing. When there is no fire happened, low pressure air shall be filled in the system pipelines for purposes of detecting, and therefore the system has dry pipe characteristics. With view to the characteristics of dry pipe, it is suitable for installing in the places that need water for fire extinguishing but can’t by accident spray the wrong place, for example in laboratory, archives, valuables storeroom, and computer facilities as well as valuables warehouse, etc. Some luxurious hotel in overseas will also adopt such system for use. In addition, the pre-action alarm valves system can be installed in areas of high temperature, cold and freezing condition in place of dry system.
A．High quality of ductile cast iron provided materials reference for valve body and cover production which are electro-statically coated with epoxy resin powder to ensure high ability of corrosion resistance.。
B．Y-pattern wide valve chamber construction with low pressure losses at the highest speed of flow rate; strong anti-cavitation ability and no noises.
C．Main parts are made of stainless steel and copper to prevent rust and jamming from occurring.
D．Compressed air is filled in the pipeline system above the Wet system alarm valve at normal time, protecting the pipe wall, reducing corrosion and easy monitoring the pipeline at any time whether there is leakage happens
E．The distribution pipe behind the fire alarming valve is filled with air instead of water so as to avoid accidental spraying and pipeline leakage occurring. Also used as a preliminary pre-action alarming in low and high temperature areas.
F．Seawater resistance and stainless steel materials to be provided for application
