3
*Teflon is a trademark of the DuPont Corp.
21 ft.-lbs.
(28.6 Nm)
may distort the
orifice seal, resulting in leakage.
Step 5. To install the escutcheon
plate, align it with and press it over
the sprinkler body until the outer edge
of the escutcheon meets the
mounting surface.
CAUTION: Do not wrench or turn
the deflector, as this action may
damage the sprinkler and cause it
to leak under pressure.
Special care must be taken when
installing with a CPVC system.
Sprinklers must be installed after the
CPVC manufacturer's recommended
setting time for the primer and
cement to ensure that neither
accumulate within the sprinkler.
Special care must be taken when
installing with a copper system.
Sprinklers must be installed only after
the inside of the sprinkler drop and
associated fittings have been wire
brushed to remove any flux. Residual
flux can cause corrosion and in
extreme cases can impair proper
sprinkler operation.
Design
Data
Design Requirements — Extended Coverage Applications
Installation
All Central Model GB-20 Recessed
Pendent and Pendent Automatic
Sprinklers must be installed accord-
ing to current NFPA 13 Standards
and these installation instructions.
Deviations from these requirements
and standards or any alteration to the
sprinkler itself will void any warranty
made by Central Sprinkler Company.
In addition, installation must also
meet local government provisions,
codes, and standards as applicable.
The system piping must be properly
sized to ensure the minimum required
flow rate at the sprinkler. Check for
the proper model, style, orifice size,
and temperature rating prior to
installation. Install sprinklers after the
piping is in place to avoid mechanical
damage; replace any damaged units.
Upon completion of the installation,
the system must be tested per
recognized standards.
In the event of a thread leak,
remove the unit, apply new pipe joint
compound or tape, and reinstall.
Installation Sequence
Step 1. The unit must be installed in
the pendent position.
Step 2. The face of the sprinkler
fitting should be installed a nominal
9
⁄
16
"
±
3
⁄
16
"
(14.3 mm
±
4.8 mm
) behind the
ceiling line as shown in the
installation diagram on page two.
Adjustments may be made via the
push-on escutcheon plate to
compensate for variations in the
fitting.
Do not use the push-on escutcheon
plate to hold the unit in position. The
sprinkler will function properly only
when the system piping is anchored
to the building structure. Otherwise
reaction forces from system initiation
could alter the sprinkler alignment
and disrupt the pattern.
Step 3. Use only a non-hardening
pipe joint compound or Teflon* tape.
Apply only to the male threads.
Step 4. Hand tighten the sprinkler
into the fitting. Use a Central
Combination Sprinkler Wrench for
pendent sprinklers and a GB-20
Wrench for pendent or recessed
pendent styles to tighten the unit into
the fitting. A leak-tight joint requires
only 7 to 14 ft.-lbs.
(9.5 to 19.0 Nm)
of
torque; a tangential force of 14 to 28
lbs.
(62.3 to 124.5 N)
delivered through a
6"
(150 mm)
handle will deliver
adequate torque. Torque levels over
Care &
Maintenance
Sprinklers must be handled care-
fully. They must not be transported or
stored where ambient temperature
may exceed 100
o
F/38
o
C. For best
results, store them in a dry, cool
location in the original shipping
package.
Do not install sprinklers that have
been dropped or visibly damaged.
Sprinklers should never be painted,
coated, plated, or altered in any other
way from manufactured condition or
they may not function properly. Any
sprinklers altered in such a manner
must be replaced.
The owner is responsible for the
proper operating condition of all fire
protection devices and accessories.
The NFPA standard 25 entitled,
“Inspection, Testing and Maintenance
of Water-Based Fire Protection
Systems”, contains guidelines and
minimum maintenance requirements.
Furthermore, the local
Authority
Having Jurisdiction may have addi-
Coverage Area
Maximum Distance
Minimum Flow
Minimum Pressure
(ft. x ft.)
Off Wall
gpm
(Lpm)
psi
(bar)
16 x 16
(4.9 x 4.9)
8 feet
(2.4 m)
26
(98.5)
11.1
(0.8)
18 x 18
(5.5 x 5.5)
9 feet
(2.7 m)
33
(125.1)
17.9
(1.2)
20 x 20
(6.1 x 6.1)
10 feet
(3.0 m)
40
(151.6)
26.3
(1.8)
The Model GB-20 Pendent and Recessed Pendent Sprinklers are U.L. Listed for
Extended Coverage applications in Light Hazard Occupancies only.
OBSOLETE
