Model B1 Accelerator
Features
• Quickens the operation of dry pipe valves.
• Can potentially increase the number of automatic sprin-
klers controlled by one dry pipe valve.
• Equalizes rapidly as dry system is being filled with air to
required pressure.
• Adjusts without operation for small fluctuations in system
air pressure.
• Dependable in operation, compact and light-weight con-
struction.
• Accelo-Check prevents water and debris from entering
critical areas, minimizing the need of removing cover
plates, etc. to reset or clean internal mechanisms.
• Tested and approved for use with Reliable dry pipe and
preaction systems.
• UL Listed, FM Approved
Product Description
The Reliable Model B1 Accelerator with integral Accelo-Check
(anti-flooding device) is used to speed up the operation of
both dry pipe valves (in dry-type automatic sprinkler systems)
and deluge valves (in preaction sprinkler systems). Both
of these systems utilize pressurized air or nitrogen in the
piping, instead of water, to prevent freezing or to prevent the
accidental release of water.
The accelerated operation of the dry pipe valve permits
an increase in both the number of sprinklers that can be
controlled by one dry pipe valve and the volume of the dry
system that can be installed.
Approvals
1. Listed by Underwriters Laboratories, Inc.
2. Underwriters’ laboratories of Canada for up to 1500 gal.
(5678 liters) systems.
3. Approved by Factory Mutual Research Corporation
4. Loss Prevention Council
Accelerator Operation
The Model B1 Accelerator is a normally-closed valve with ½”
NPT inlet and outlet ports, that is highly sensitive to the rate of
air pressure change in a dry pipe sprinkler system. This device
retains normal dry system air pressure in the top chamber even
though pressure in the system may be dropping as a direct
result from one or more sprinklers opening.
www.reliablesprinkler.com
Fig. 1 illustrates a cross-section of the Model B1 Accelerator
in the “closed” position while being pressurized. Upon initial
setup, the Accelerator is filled by air from the dry pipe system
via a ½” NPT connection. Air passes through its filter assembly
(item #18) and passageway E to the device’s middle chamber.
This air pressure also lifts the diaphragm assembly (Items #5
through #8) off of the push rod (item #10) thereby opening up
passageway G. The air then completely fills the top chamber to
the match the system pressure. When filled, the diaphragm as-
sembly rests on the end of the push rod closing passageway G
to all but very small amounts of air movement, thereby allowing
slow changes in pressure between the top and middle cham-
bers due to temperature change or small leaks.
Upon a significant air-pressure decay of the sprinkler system
piping (such as sprinkler activation), the retained air pressure
in the Accelerator top chamber exerts a net-downward force
across the diaphragm assembly and pushrod (items 5-8 & 10).
This forces the poppet (item #15) to open thereby allowing sys-
tem air pressure to pass out of the Accelerator ½” outlet port
and into the intermediate chamber of the dry pipe valve (or to
atmosphere depending on the type of system to which it is in-
stalled). This in turn will activate the dry pipe valve. Simultane-
ously, pressurized air also passes through the Accelerator and
closes the integral Accelo-Check (items #11, #19 through #25)
by pressurizing cavity H, thereby preventing water and water-
borne debris from entering the internal restriction area in pas-
sageway E. This increases the reliability of the Accelerator and
reduces the maintenance which would otherwise be required to
clean it after each operation.
Model B1 Accelerator
with Integral Accelo-Check
Bulletin 323 May 2019
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