Reliable N252 User manual

Model N252 EC Pendent and
Recessed Pendent Extended
Coverage Area Density
Sprinklers for Storage and
Extra Hazard Applications
Bulletin 008 Rev.B
Model N252 (SIN RA0852)
Nominal K-Factor = 25.2
Features
1. Provides maximum coverage areas up to 14 ft.
(4,27 m) by 14 ft. (4,27 m) 196 ft2(18,21 m2).
2. Can be installed recessed below finished
ceilings with 12
²(13 mm) adjustment. Available in
brass, chrome, black plated and white polyester
coated finishes.
3. 165 °F(74°C) and 212 °F (100 °C) temperature
ratings.
4. Listed by Underwriters’ Laboratories Inc,
Underwriters’ Laboratories for use in Canada
and Factory Mutual.
5. cULus Listed for unobstructed or
noncombustible obstructed construction.
The Reliable Automatic Sprinkler Co., Inc. 103 Fairview Park Drive, Elmsford, New York, 10523
Bulletin 008 Rev.B
Listings and Approvals
Listed by Underwriters’ Laboratories Inc.,
UL certified for Canada (cULus) and
FM Approved (Pendent only).
NYC MEA 258-93-E
UL Listing Categories
Sprinklers, Automatic & Open
Sprinklers for Storage Protection (Area/Density)
UL Guide Number
VNIV
Product Description
The Models N252 EC Pendent and Recessed Pendent
Sprinklers are control mode, extended coverage
sprinklers for storage and extra hazard density/area
applications. This includes protection of the storage and
display of Class I through Class IV commodities,
non-expanded Group A Plastics, and non-expanded,
exposed Group A Plastics in retail stores. The Model
N252 EC sprinklers offer maximum coverage areas up to
14 ft by 14 ft (196 ft2), which is almost twice of that
provided by standard coverage sprinklers. This offers
the advantage of decreasing the number of required
sprinklers, reducing labor and material costs.
Operation
The Reliable Model N252 Extended Coverage
Pendent and Recessed Pendent Sprinklers utilize a
levered fusible alloy solder link. When the rated
temperature is reached, the solder melts and the two link
halves separate allowing sprinkler to operate and water
to flow.
N252 EC Pendent
N252 EC Recessed Pendent
(UL approved only)

2.
Fig. 1 Model N252 EC Pendent Fig. 2 Model N252 Recessed EC Pendent/ FP
Fig. 3 Model N Wrench
Installation
Model N252 sprinklers are to be installed as
shown. Model FP escutcheons, illustrated herewith,
are the only recessed escutcheons to be used with
Model N252 EC Recessed Pendent Sprinklers. Use
of any other recessed escutcheon will void all
approvals and warranties. When handling
sprinklers, hold sprinklers only on frame arms and do
not apply any force on the link assembly. For
installing Model N252 EC pendent and recessed
pendent sprinklers use only the Model N wrench (ref.
Fig. 3). Use of wrenches other than that specified may
damage these sprinklers. Sprinklers should be
tightened between 22 to 30 ft. - lbs. (29,8 - 40,7 Nm)
torque. Sprinklers not tightened to recommended
torque may cause leakage or impairment of the
sprinklers. Damaged sprinklers must be replaced
immediately.
Link Assembly
Frame Arm
Model N Wrench

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 1²NPT
(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
ft2(18.2 m2); minimum area of coverage is 100 ft2
(9.3 m2). 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/ft2(17.5 mm/min) applied
over 14 ft x 14 ft (4.3 m x 4.3 m) spacing, or 196 ft2
(18.2 m2), 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/ft2(17.5 mm/min) applied
over 14 ft x 12 ft (4.3 m x 3.7 m) spacing, or 168 ft2
(15.6 m2), 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.

The equipment presented in this bulletin is to be installed in accordance with the latest pertinent Standards of the National Fire Protection Association, Factory Mutual Research
Corporation, or other similar organizations and also with the provisions of governmental codes or ordinances whenever applicable.
Products manufactured and distributed by Reliable have been protecting life and property for over 80 years, and are installed and serviced by the most highly qualified and reputa-
ble sprinkler contractors located throughout the United States, Canada and foreign countries.
The Reliable Automatic Sprinkler Co., Inc.
[phone] Sales Offices
[phone] Sales Fax
[phone] Corporate Offices
www.reliablesprinkler.com Internet Address
Manufactured by
Revision lines indicate updated or new data.
E.G. Printed in U.S.A. 7/07 P/N 9999970286
Recycled
Paper
•Maximum area of coverage per sprinklers is 196
ft2(18,2 m2). Minimum area of coverage is 100 ft2
(9,3 m2). Maximum spacing between sprinklers is
14 ft (4,3m), minimum spacing between
sprinklers is 8 ft. (2,44m).
•Area/density designs should be the same as 11.2
k-factor standard spray control mode
area/density sprinklers. Otherwise use the same
design criteria as 5.6 or 8.0 k-factor standard
spray control mode sprinklers.
•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/ft2(17.5mm/min) applied
over 14 ft x 14 ft (4,3m x 4,3m) spacing, or 196 ft2
(18m2), 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/ft2(17.5 mm/min) applied
over 14 ft x 12 ft (4.3 m x 3.7 m) spacing, or 168 ft2
(15.6 m2), 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).
• All other design details should be in accordance
with FM Global Data Sheet 2-8N, as well as any
other applicable FM Global Data Sheet.
Maintenance
The Models N252 EC Pendent and Recessed
Pendent Sprinklers should be inspected quarterly
and the sprinkler system maintained in accordance
with NFPA 25, and local jurisdictional requirements.
Do not clean sprinklers with soap and water,
ammonia, or any other cleaning fluids or solvents.
Remove dust by using a soft brush or gentle
vacuuming. Remove any sprinkler that has been
painted (other than factory-applied) or otherwise
altered after leaving the factory. A stock of spare
sprinklers should be maintained to allow quick
replacement of damaged or operated sprinklers.
Prior to installation, sprinklers should be maintained in
the original cartons and packaging until used to
minimize the potential for damage to sprinkler that
would cause improper operation or non-operation.