TFP591
Page 2 of 4
NOTICE
The TFP Dry Type Sprinklers must be
installed and maintained in compli-
ance with the applicable technical data
sheet. Failure to do so may impair the
performance of these devices.
Clearance Hole
The Model DSB-2 Dry Sprinkler
Boot may be used with a maximum
2-1/2 in. (63,5 mm) diameter clearance
hole (i.e., the diameter of the hole in
the ceiling or wall being penetrated by
the dry type sprinkler, Ref. Figures 1 or
2). Based on the diameter of the Dry
Type Sprinkler Barrel, the designated
maximum clearance hole will com-
pensate for non-centering of the Dry
Type Sprinkler Barrel within the clear-
ance hole. Where centering can be
maintained, a clearance hole as large
as 3 in. (76,2 mm) in diameter can be
accommodated.
NOTE: The clearance hole adjacent
to the DSB-2 cannot be larger than
2-1/2 in. (63,5 mm) diameter for a
non-concentric installation or 3 in.
(76,2 mm) diameter for a concentric
installation. Otherwise, the DSB-2
cannot perform as intended by closing
the air gap.
NOTE: Clearance holes greater than
specified cannot be filled in with foam
insulation, etc. In order for the DSB-2
to be effective in closing the air gap it
must seat and seal against the smooth
material of the ceiling or wall.
Exposure Length
When Dry Sprinklers are to be used in
wet pipe sprinkler systems protecting
areas subject to freezing temperatures
(e.g., sprinkler drops into freezers), con-
sideration must be given to the appro-
priate length of the sprinkler that will
prevent freezing of the water in the con-
necting pipes due to conduction. When
the temperature surrounding the wet
pipe sprinkler system is maintained at
a minimum temperature of 40°F (4°C),
the following are the minimum recom-
mended lengths between the face of
the sprinkler fitting and the outside sur-
face of the protected area (i.e., length
exposed to minimum ambient tempera-
ture of 40°F (4°C) — Ref. Figure 3):
• 12 inches (300 mm) when the tem-
perature within the protected area is
-20°F (-29°C)
• 18 inches (450 mm) when the tem-
perature within the protected area is
-40°F (-40°C)
• 24 inches (600 mm) when the tem-
perature within the protected area is
-60°F (-51°C)
For protected area temperatures
between those given above, the
minimum recommended length from
INSULATED
FREEZER
STRUCTURE
TFP
DRY TYPE
SPRINKLER
(44,5 mm)
CLEARANCE
HOLE
1-3/4" DIA.
"BOOT"
"ADHESIVE"
3-3/4" DIA.
(95,3 mm) REF.
2" (50,8 mm)
REF.
(ENDS ON
OPPOSING
SIDES OF
"STRAP TIES"
BOOT)
TFP DS-C OR DS-ECC DRY
PENDENT CONCEALED SPRINKLER
CLEARANCE
HOLE
(63,5 mm)
2-1/2" DIA.
MODEL DSB-2
DRY SPRINKLER
BOOT
INSULATED
FREEZER CEILING
STRUCTURE
FIGURE 1
TYPICAL INSTALLATION OF MODEL DSB-2 DRY SPRINKLER BOOT
WITH SERIES DS-1 DRY PENDENT SPRINKLER
FIGURE 2
TYPICAL INSTALLATION OF MODEL DSB-2 DRY SPRINKLER BOOT
WITH SERIES DS-C DRY PENDENT CONCEALED SPRINKLER
