Preaction sprinkler system

There are numerous types of sprinkler systems. They can be wet pipe, preaction, dry pipe, deluge or antifreeze. 

Dry Pipe. The dry pipe systems are only desirable where adequate heat is not provided. This wouldn t be used for a cleanroom installation. It might be used for outside storage rooms or unheated areas of exposing building. It is slower than the wet pipe or preaction system and could allow a fire to get ahead of the sprinkler system. It is not acceptable for protection of flammable liquids. 

The preaction system. In libraries, museums, or other locations where special contents may be housed, the preaction sprinkler system must be used. Any operation of the sprinkler system in the absence of fire would be devastating to the building contents. Most fire safety professionals identify two events that must take place in order to activate the system. First, the heat of a fire will melt the fusible link in the sealed sprinkler heads. Second, a detector must open the deluge valve to admit the water. In the absence of either of these two events, the sprinkler system will not function. The biggest disadvantage of this system is the cost. However, when contents of great value must be protected, the expense of a preaction system may not be restrictive. 

Gas Compression Station Gas Release NFPA 30 1. Hydrants 2. Monitors 3. CO2 System 4. Preaction Sprinkler 1. NFPA 24 2. NFPA 24 3. NFPA 12 4. NFPA 13... 

Sprinkler protection should be provided as for any storage facility handling similar material products. In storage areas that are always above freezing, preaction type systems electrically activated by a separate fire/heat detection system are often used. 

Preaction Systems This is a special fonii of dry-pipe system. The piping may or may notbe under pressure. There are sensors in protected areas besides sensors at each sprinkler head. The special sensors detect a fire and open a valve to fiU the pipe with water. The special sensors operate before those in the sprinkler heads. This design reduces the delay found in a dry-pipe system. 

Com bi ned Systems These systems combine features of a dry-pipe system and a preaction system. Pipes are filled with air under pressure. Supplementary sensors open a water valve and air exhaust ports. This allows the piping to fill completely with water before the sprinklers open. 

Deluge Systems A deluge system is similar to a preaction system. All sprinklers are open at aU times. Firedetecting devices activate the water valve, allowing water to emerge from all sprinkler heads. 

The preaction system has several advantages over a dry-pipe system. The valve is opened sooner because the detection system will usually respond to the fire prior to operation of the first sprinkler. Sprinkler piping is normally dry thus, preaction systems are not subject to freezing and can be used when a dry-pipe system is required. 

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