TFP443
Page 3 of 6
Technical
Data
Approvals
UL and C-UL Listed
The TYCO RAPID RESPONSE Series
LFII Residential Flat-Plate Concealed
Pendent Sprinklers are only listed with
the Series LFII Concealed Cover Plates
having a factory-applied finish.
These Cover Plates and their part num-
bers can be found in the Ordering Pro-
cedure section at the end of this data
sheet.
For details on approvals, refer to the De-
sign Criteria section.
Maximum Working Pressure
175 psi (12,1 bar)
Discharge Coefficient
K = 4.9 GPM/psi
1/2
(70,6 LPM/bar
1/2
)
Temperature Rating
Sprinkler: 160°F (71°C)
Cover Plate: 139°F (59°C)
Vertical Adjustment
1/2 inch (12,7 mm)
Finishes
Refer to the Ordering Procedure section.
Physical Characteristics
Cover Plate/Retainer Assembly:
Cover Plate . . . . . . . . . . . . . . . . . . . . . Copper
Ejection Spring . . . . . . . . . . . . Stainless Steel
Retainer
. . . . . . . . . . . . . . . . . . . . . . . . Brass
Sprinkler/Support Cup Assembly:
Body . . . . . . . . . . . . . . . . . . . . . . . . . . . Brass
Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . Bronze
Saddle. . . . . . . . . . . . . . . . . . . . . . . . . . Brass
Sealing Assembly. . . . . . . . . . . . . . Beryllium
Nickel w/ TEFLON
Soldered Link Halves . . . . . . . . . . . . . . Nickel
Lever . . . . . . . . . . . . . . . . . . . . . . . . . . Bronze
Compression Screw. . . . . . . . . . . . . . . Brass
Deflector . . . . . . . . . . . . . . . . . . . . . . . Bronze
Guide Pin Housing . . . . . . . . . . . . . . . Bronze
Guide Pins . . . . . . . . . . . . . . . . . . . . . Bronze
Support Cup . . . . . . . . . . . . . . . . . . . . . Steel
Operation
When exposed to heat from a fire, the
Cover Plate, which is normally soldered
to the Retainer at three points, falls away
to expose the Sprinkler/Support Cup As-
sembly. At this point, the Deflector, sup-
ported by the Guide Pins, drops down
to its operated position.
The Solder Link Element of the Sprinkler/
Support Cup Assembly is comprised of
two link halves that are soldered togeth-
er with a thin layer of solder. When the
rated temperature is reached, the sol-
der melts and the two link halves sepa-
rate, allowing the sprinkler to activate
and flow water.
Design Criteria
The TYCO RAPID RESPONSE Series
LFII Residential Flat-Plate Concealed
Pendent Sprinklers (TY2524) are UL
and C-UL Listed for installation in ac-
cordance with this section:
Residential Sprinkler Design Guide
When conditions exist that are outside
the scope of the provided criteria, re-
fer to the Residential Sprinkler Design
Guide TFP490 for the manufacturer's
recommendations that may be accept-
able to the authority having jurisdiction.
System Type
Per the UL Listing, wet pipe and dry pipe
systems may be utilized. Per the C-UL
Listing, only wet pipe systems may be
utilized.
Refer to Technical Data Sheet TFP485
about the use of Residential Sprinklers
in residential dry pipe systems.
Ceiling Types
Smooth flat horizontal, or beamed, or
sloped, in accordance with the 2013
Edition of NFPA 13D, 13R or 13 as
applicable.
Hydraulic Design
(NFPA 13D and 13R)
For systems designed to NFPA 13D or
NFPA 13R, the minimum required sprin-
kler flow rate are given in Tables A and
B as a function of temperature rating
and the maximum allowable coverage
areas. The sprinkler flow rate is the mini-
mum required discharge from each of
the total number of “design sprinklers”
as specified in NFPA 13D or NFPA 13R.
The number of “design sprinklers” spec-
ified in NFPA 13D and 13R for wet pipe
systems is to be applied when designing
dry pipe systems.
Hydraulic Design
(NFPA 13)
For systems designed to NFPA 13, the
number of design sprinklers is to be
the four most hydraulically demanding
sprinklers. The minimum required dis-
charge from each of the four sprinklers
is to be the greater of the following:
• The flow rates given in Tables A and
B as a function of temperature rating
and the maximum allowable cover-
age area
• A minimum discharge of 0.1 gpm/ft
2
.
over the “design area” comprised of
the four most hydraulically demand-
ing sprinklers for the actual coverage
areas being protected by the four
sprinklers
The number of “design sprinklers”
specified in NFPA 13 for wet pipe sys-
tems is to be applied when designing
dry pipe systems.
Dry Pipe System Water Delivery
When using the Series LFII Residential
Flat-Plate Concealed Pendent Sprinklers
(TY2524) in dry pipe sprinkler systems,
the time for water delivery must not ex-
ceed 15 seconds for the most remote
operating sprinkler.
Obstruction to Water Distribution
Sprinklers are to be located in accor-
dance with the obstruction rules of
NFPA 13D, 13R, and 13 as applicable
for residential sprinklers as well as with
the obstruction criteria described within
the Technical Data Sheet TFP490.
Operational Sensitivity
Install sprinklers relative to the ceiling
mounting surface as shown in Figure 3.
The Series LFII Residential Flat-Plate
Concealed Pendent Sprinklers must
not be used in applications where the
air pressure above the ceiling is greater
than that below. Down drafts through
the Support Cup can delay sprinkler op-
eration in a fire situation.
Sprinkler Spacing
The minimum spacing between sprin-
klers is 8 feet (2,4 m). The maximum
spacing between sprinklers cannot ex-
ceed the length of the coverage area
(Table A) being hydraulically calculated
(e.g., a maximum of 12 feet for a 12 ft. x
12 ft. coverage area or 20 feet for a 20
ft. x 20 ft. coverage area.)
