Grinnell F920B Manual

E L
10 DORRANCE STREET PROVIDENCE, R. I. 02903
AQUAMATIC SPRINKLER, MODEL F920B
PENDENT, 1/2" ORIFICE
COMPONENTS
PORT
1-Body
2-lnlet
PISTON
3-Piston
ASSEMBLY
Assembly
4-Spring PORT
5-Pilot Valve
6-Yoke and 4
Deflector
Assembly
7-Spirol Pin
8-Locking Pin
0-RING
PILOT
DIM. INCHES
MM
VALVE
A
3.75 95.3
B 1.06 26.9
6
C
1.44
36.6
. J
DESCRIPTION
The Model F920B Aquamatic Sprink-
ler is an automatic sprinkler designed
to reset itself after operation. It is
available with temperature ratings of
165° F/74° C or 212° F/100° C, with
plain or chrome plated finishes and is
rated for 175 psi pressure service.
Model F920B Aquamatic Sprinklers
are designed for pendent installation
in wet pipe sprinkler systems. The
sprinklers should only be installed in
systems with water supplies free of
contaminants which could interfere
with proper operation of the sprinklers.
APPROVALS
Model F920B Aquamatic Sprinklers
with 165F/74C and 212F/100C tem-
perature ratings are
I isted by Under-
writers Laboratories, Inc. and approved
by Factory Mutual. Aquamatic Sprink-
lers with 165F/74C temperature rating
are listed by Underwriters' Laboratories
of Canada.
DESIGN
Principal components ofthe Aquamatic
Sprinkler are the Inlet (2), Body (1),
Yoke-Deflector Assembly (6) with an
internally mounted Pilot Valve (5) and
a Piston Assembly (3).
The Piston Assembly, with an integral
Ball Check and Strainer, is held in its
proper vertical position by a Spring
and three guides which extend up into
the Inlet. The Pilot Vatve, which has
a heat responsive bi-metallic Snap
Disc, is staked in pqsition with a Pin
(7). The Body and Inlet are also
staked together with a Pin (8).
GENERAL INSTRUCTIONS
Before Aquamatic Sprinklers are in-
stalled, the system piping must be
10-16-78
Printed in U.S.A.
CLOSED
flushed and the sprinklers must be
inspected and precharged.
Flushing System Piping. Water supply
piping of systems with Aquamatic
Sprinklers must be free of chips, oil,
rust and all foreign matter. Under-
ground yard mains and lead-in connec-
tions must be flushed in compliance
with NFPA Standards and/or require-
ments of approval authorities. System
piping to Aquamatic Sprinklers must
also be flushed sequentially through
cross mains, sprinkler branch lines and
drop nipples until all piping is clean.
Inspection.
Inspect each Aquamatic
Sprinkler for physical damage. Special
attention should be given to the
Deflector, Snap Disc and Snap Disc
Locking Pin (7). Damaged sprinklers
should be returned to the factory.
Under no conditions, should repairs
be attempted.
· Precharging. Each Aquamatic Sprink-
ler must be precharged before installa-
tion in the system piping. Sprinklers
which
will not be
exposed to freezing
conditions before being placed in
service must be precharged with
water.
Sprinklers which
will be
ex-
posed to freezing must be precharged
with air; only clean oil free air should
be used. The procedure for precharg-
ing Aquamatic Sprinklers is as follows:
1. Assemble a Precharging Manifold as
shown. Larger Manifolds are per-
mitted subject to pressure require-
ments noted in Instruction 2.
2. Connect the Manifold to a water or
air supply which will permit pre-
AOUAMATIC
SPRINKLERS
8
AIR OR WATER
SUPPLY
PRECHARGING MANIFOLD
charging the sprinklers to at least
the system pressure and which will
be adequate for operation of one or
more sprinklers at a minimum of 10
psi residual pressure on the Mani-
fold Pressure Gauge. The Manifold
should be located to permit ade-
quate drainage when connected to
a water supply.
3. Close Manifold Valves No. 1 and 2
and install the sprinklers in the
Manifold as shown. Under most
pressure conditions, hand tight
installation will be adequate.
4. Open Valve No. 1 while observ-
ing the sprinklers and the Pressure
Gauge. While precharging the
sprinklers, there may be spurting
until the Piston Chambers are
pressurized.
5. Operate each sprinkler by applying
minimum heat with a propane
torch to the Sprinkler Snap Disc
until the sprinkler opens. The
sprinkler should then discharge at
full flow for a short period after
which it should close tightly. The
discharge period can be shortened
by cooling the Snap Disc with a few
drops of water.
Caution: Do not
overheat. Do not discolor the Snap
Disc.
Sec. 5 AOS/1