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Back Figure 8-7.—Air pressure maintenance device. | Up Utilitiesman (Advanced) - Manual for electric, plumbing, water and other utilities | Next Pre-Action System |
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 Arrange-
ment of levers, links, and latches on the
valve clapper provides the leverage for the
closing force placed on the water clapper (fig.
8-8).
Water Deluge System
A water deluge system (fig. 8-9) is
used where there is an extra hazard, such
as areas where flammable liquids or pro-
pellants 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 con-
nected to the piping network are open and the
water supply is controlled by a water deluge
Figure 8-9.Deluge system.
8-7
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