3.
Sprinkler
Model
Type
Temperature
Rating
Maximum
Ambient
Ceiling Temp.
Nominal
K-Factor
Orifice
Size
Thread
Size
Sprinkler Ht.
Inch (mm)
Sprinkler
Identification
Number (SIN)
°
F
°
C
°F
°
C
N252 EC
Pendent/
Recessed
Pendent
165
74
100
38
25.2
1 inch
1
²
NPT
(R1)
3.6 (91,5)
RA0852
212
100
150
66
Technical Data
Design Criteria for UL and C-UL
The Models N252 EC Pendent and Recessed
Pendent Sprinklers are cULus Listed control-mode,
extended coverage density/area sprinklers for
installation in accordance with the extended
coverage pendent spray sprinkler criteria of NFPA 13,
or other applicable NFPA standards, when used in
combination with the following guidelines:
• Protection for extra hazard and high-piled
storage occupancies using NFPA 13
density/area criteria.
• Suitable for use in wet pipe systems, and in
dry-pipe and preaction systems as specifically
allowed for pendent sprinklers in NFPA 13.
• cULus
Listed
for
“unobstructed”
or
non-combustible “obstructed” construction.
Given that the Model N252 EC sprinklers are
specifically listed for noncombustible obstructed
construction, they may be installed within trusses
or bar joists having noncombustible web
members greater than 1 inch (25.4 mm) when
applying the “Four Times Rule” as defined in
NFPA 13 under “Obstructions to Sprinkler
Discharge Pattern Development.”
• Maximum area of coverage per sprinklers is 196
ft
2
(18.2 m
2
); minimum area of coverage is 100 ft
2
(9.3 m
2
). Maximum spacing between sprinklers
is 14 ft (4.3 m); minimum spacing between
sprinklers is 8 ft (2.44 m).
• Minimum flow requirement is based on the
design density applied over the actual area of
coverage per sprinkler. Example 1, a design
density of 0.43 gpm/ft
2
(17.5 mm/min) applied
over 14 ft x 14 ft (4.3 m x 4.3 m) spacing, or 196 ft
2
(18.2 m
2
), would require a minimum sprinkler
design flow rate and pressure of 84.3 gpm (319.2
L/min) at 11.2 psi (0.77 bar). Example 2, a design
density of 0.43 gpm/ft
2
(17.5 mm/min) applied
over 14 ft x 12 ft (4.3 m x 3.7 m) spacing, or 168 ft
2
(15.6 m
2
), would require a minimum sprinkler
design flow rate and pressure of 72.2 gpm (273.3
L/min) at 8.2 psi (0.57 bar).
• Maximum working pressure - 175 psi (12.1 bar).
• Minimum end head pressure - 7 psi (0.5 bar).
• The minimum clearance between the deflector
and the top of storage is 3 ft. (0,92m). For
clearances of 3 ft. (0,92m) up to 4 ft. (1,21m), the
minimum design pressure is 22 psi (1,52 bar). For
clearances of 4 ft. (1,21m) and greater, the
minimum design pressure is established by the
minimum flow requirement (however, the
pressure can never be less than 7 psi (0,48 bar)).
• Available temperature ratings are Ordinary, 165
°
F (74
°
C) and Intermediate, 212
°
F (100
°
C).
Selection of temperature rating is based on the
expected maximum ambient temperature
exposure, or in accordance with the high-piled
storage density/area curve requirements
specified in Chapter 12 of the 2002 edition of
NFPA 13. In accordance with the listing of the
sprinkler, the density curves normally associated
with high temperature rated sprinklers [286
°
F
(141
°
C)] may be used with either the ordinary or
intermediate temperature rating of the N252 EC
sprinklers.
• The obstruction criteria in NFPA 13 for Extended
Coverage Pendent Sprinklers shall be used for
the locating and positioning Model N252 EC
sprinklers relative to obstructions.
Design Criteria for FM
The Model N252 EC Pendent Sprinklers are FM
approved to be utilized in accordance with the
following guidelines:
• Sprinklers may be used to protect any
occupancy for which there is an area/density
design criterion up to 11.2 k-factor standard
spray control mode area/density sprinklers
specified in FM Global Data Sheets. Model N252
EC sprinklers are not approved for use in control
mode specific application or suppression mode
protection.
• Suitable for use in wet pipe systems, and in
dry-pipe and preaction systems as specifically
allowed for pendent sprinklers in NFPA 13.
• Follow
obstruction
requirements
for
control-mode area/density sprinklers in FM Data
Sheet 2-8N section 4-6.5.
