Star S430 Manual

Dry Pipe Valve Accelerator
Model S430

GENERAL DESCRIPTION

The Star Model S430 Accelerator is a quick opening de-
vice intended for attachment to either the 4 or 6 inch Star
Model A or A-1 Dry Pipe Valves. The S430 reduces the
time for valve operation following the operation of one or
more automatic sprinklers.
The S430 automatically adjusts to both small and slow
changes in system pressure, but trips when there is a
rapid and steady drop in pressure (as in the case of a
sprinkler operation). Upon tripping, the Accelerator trans-
mits system air pressure to the intermediate chamber of
the Model A or A-1 Dry Pipe Valve. This neutralizes the
differential pressure holding the Model A or A-1 Dry Pipe
Valve closed and permits it to open.
The S430 has a unique, positive action, internal anti-flood
device and a ball float which combine to prevent water
and water borne debris from entering the more sensitive
operating areas of the accelerator. The anti-flood device
seals and latches immediately upon operation of the
S430 without having to wait for a pressure build-up in the
intermediate chamber of the dry pipe valve. The latching
feature keeps the anti-flood device sealed, even while the
system is being drained. The ball float seals the pilot
chamber inlet port if there is an inadvertent trip of the dry
pipe valve, due for example, to an air compressor failure
combined with a slow loss in system air pressure due to a
leak.
WARNING
The Model S430 Dry Pipe Valve Accelerator described
herein must be installed and maintained in compliance
with this document, as well as with the applicable stand-
ards of the National Fire Protection Association, in addi-
tion to the standards of any other authorities having juris-
diction. Failure to do so may impair the integrity of this
device.
The owner is responsible for maintaining his fire protec-
tion system and devices in proper operating condition.
The installing contractor or sprinkler manufacturer should
be contacted relative to any questions.

TECHNICAL DATA

Approvals
UL and ULC Listed. FM Approved.
NYC Accepted under MEA 177-99-E.
Maximum Working Water Pressure
175 psi (12.1 bar)
Maximum Working Air Pressure
60 psi (4.1 bar)
Pressure Decay For Trip
1 psi/min (0.07 bar/min)
STAR SPRINKLER INC.
414-570-5000 • 800-558-5236 • FAX 414-570-5010
#1306
Physical Characteristics
Body components constructed of alodine coated alumi-
num alloy with austenitic series stainless steel internal
components. Seals are EPDM and silicone.

OPERATION

The Inlet Chamber of the Accelerator (Figure 1 - Set Posi-
tion) is pressurized via its connection to the system (at a
point above the maximum expected level of priming plus
drain-back water). The Pilot Chamber is, in turn, pressur-
ized through its inlet port which is formed by the annular
opening around the lower tip of the Anti-Flood Valve. As
the Pilot Chamber increases in pressure, the Differential
Chamber is pressurized through the Restriction.
The Accelerator is in its Set position while it is being pres-
surized as well as after the Inlet, Pilot Chamber and Dif-
ferential Chamber pressures have equalized. When in the
Set position, the Outlet Chamber is sealed off by the Ex-
haust Valve which is held against its seat by a combina-
tion of the Spring pushing up against the Lever and the
net downward force exerted by the pressure in the Pilot
Chamber.
Both small and slow changes in system pressure are ac-
commodated by flow through the Restriction. When, how-
ever, there is a rapid and steady drop in system (i.e., Inlet
and Pilot Chamber) pressure, the pressure in the Differen-
tial Chamber reduces at a substantially lower rate. This
condition creates a net downward force on the Plunger
which rotates the Lever. As the Lever is rotated, the Relief
Valve is raised out of the Relief Port and the Anti-Flood
Valve is depressed downward into the Pilot Chamber Inlet
Port, venting the Pilot Chamber.
The system pressure in the Inlet Chamber then forces
(raises) the Exhaust Valve off its seat. This continues the
rotation of the Lever into the tripped (latched) position
(Figure 1 - Tripped Position). As the Exhaust Valve is
raised off its seat, system pressure is transmitted to the
intermediate chamber of the dry pipe valve which neutral-
izes the differential pressure holding the valve closed.
Following the dry pipe valve trip, major water borne de-
bris is prevented from entering the Accelerator (via the
connection to the system piping) by the Strainer located
at its Inlet. Water and any fine water borne debris such as
silt is prevented from entering the Pilot Chamber by virtue
of the Anti-Flood Valve having sealed off its inlet port. The
Check Valve located downstream of the Accelerator Out-
let prevents any water borne debris from entering the Ac-
celerator via the connection to the intermediate chamber
of the dry pipe valve.
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