General
Description
The Model DV-5 Supervised Single In-
terlock Preaction System with Electric
Actuation (Fig. 1) utilizes automatic
sprinklers and a supplemental detec-
tion system. The supplemental detec-
tion system is typically comprised of
24 VDC heat detectors, smoke detec-
tors, manual pull stations, etc. Actua-
tion of the detection system automat-
ically operates (releases) the Model
DV-5 Deluge Valve, allowing water to
flow into the sprinkler piping system
and to be discharged from any sprin-
klers that may be open.
In accordance with the requirements
of the National Fire Protection Asso-
ciation, a preaction system employing
more than 20 automatic sprinklers is to
have the sprinkler piping automatically
supervised to monitor the overall in-
tegrity of the system. In the case of a
Supervised Single Interlock Preaction
System, a Riser Check Valve (that
does not require the use of priming
water) provides an air check so that
the system can be automatically pres-
surized with a nominal supervisory air
or nitrogen pressure of 10 psi (0,69
bar). A supervisory low pressure alarm
switch that is set to transfer its contacts
at nominally 5 psi (0,34 bar), on de-
creasing pressure, is utilized to indi-
cate whether there are any abnormal
leaks in the sprinkler system piping.
Loss of air pressure from the system
as a result of a damaged sprinkler or
broken piping will not cause the DV-5
Valve to open — the air pressure is for
supervisory alarm only.
Typically, the system designer selects
the detection components for a single
interlock preaction system that will re-
spond to a fire sooner than the auto-
matic sprinklers. Consequently, the
system will experience a minimal delay
in water delivery over that for a wet
pipe sprinkler system because the
system will have begun to fill with
water before a sprinkler operates.
Supervised single interlock preaction
systems are generally used to protect
areas where there is danger of serious
water damage that might result from
damaged automatic sprinklers or pip-
ing. Typically, such areas include com-
puter rooms, storage areas for valu-
able artifacts, libraries, and archives.
Single interlock preaction systems are
also effectively used to protect proper-
ties where a pre-alarm of a possible
fire condition may allow time for fire
extinguishment by alternate suppres-
sion means, prior to a sprinkler dis-
charge. In the event the fire cannot
otherwise be extinguished, the preac-
tion sprinkler system will then perform
as the primary fire protection system.
The Model DV-5 Deluge Valve (de-
scribed in Technical Data Sheet
TFP1305) is a diaphragm style valve
that depends upon water pressure in
the Diaphragm Chamber to hold the
Diaphragm closed against the water
supply pressure. When the DV-5 Valve
is set for service, the Diaphragm
Page 1 of 14 TFP1420
SEPTEMBER, 2004
Preaction System with Model DV-5 Deluge Valve
Single Interlock, Supervised — Electric Actuation
1-1/2 thru 8 Inch (DN40 thru DN200)
Technical Services: Tel: (800) 381-9312 / Fax: (800) 791-5500
(TEXT CONTINUED ON PAGE 9)
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