MECHANICAL OR LATCHED-CLAPPER DRY PIPE VALVE. - The mechanical or latched-clapper dry pipe valve operates under the same theory as other dry pipe valves. It has system air pressure against a small disk, diaphragm, or clapper. An Arrangement of levers, links, and latches on the valve clapper provides the leverage for the closing force placed on the water clapper (fig. 8-8).
A water deluge system (fig. 8-9) is used where there is an extra hazard, such as areas where flammable liquids or propellants are handled or stored, or where there is a possibility that a fire might grow faster than ordinary sprinkler systems can control. These systems are also often used in aircraft hangars where ceilings are unusually high and where drafts may deflect the direct rise of heat so that sprinklers directly over the fire would not open promptly but others, at some distance away, might open without having any effect on the fire.
In the water deluge system, all sprinklers connected to the piping network are open and the water supply is controlled by a water deluge
Figure 8-9. - Deluge system.Continue Reading