has been drained, the piping from the
system to the Accelerator must also be
drained and the Accelerator reset/in-
spected according to the instructions
given in the Setting Procedure Sec-
tion.
The rate-of-flow through the Restric-
tion has been set such that the Model
ACC-1 Accelerator provides the maxi-
mum practical sensitivity to a loss in
system pressure due to a sprinkler
operation while still being capable of
automatically compensating for nor-
mal variations in system pressure
such as are caused by environmental
temperature changes. A test for verify-
ing that the rate-of-flow through the
Restriction is within the range for opti-
mum Accelerator performance is
given in the Setting Procedure Sec-
tion.
Installation
The Model ACC-1 Accelerator must be
installed in accordance with the follow-
ing instructions:
NOTE
Failure to follow these instructions can
result in flooding of the Accelerator
and accidental tripping due to closure
of the ball float.
Step 1. The Accelerator must be posi-
tioned vertically and trimmed per the
arrangement shown in Figure 4. Apply
pipe thread sealant sparingly to male
threads only.
Step 2. The Strainer located at the
Accelerator Inlet must be installed with
its arrow pointed towards the Accel-
erator.
Step 3. The Check Valve located in
the line between the Accelerator Out-
let and the intermediate chamber of
the dry pipe valve must be installed
horizontally with its arrow pointed in
the direction of flow to the intermediate
chamber.
Step 4. The connection to the system
piping must be located so that drain
back water will not flow into the Accel-
erator piping and it must be located at
a point above the maximum expected
level of the drain back/condensate
water.
If the connection is made to the riser,
it must be located at least two feet
above the level of the dry pipe valve
priming water. Connections to a feed
or cross main must be made either to
thesideortopofthemain.
Step 5. The accelerator/dry pipe valve
combination must be installed in a
heated enclosure which is maintained
at a minimum temperature of
40°F/4°C. Heat tracing is not permit-
ted.
Step 6. Close the Accelerator Control
Valve until the Model ACC-1 Accelera-
tor is ready to be placed in service.
The Accelerator Control Valve must
be closed during hydrostatic testing of
the system in order to prevent damage
to the Ball Float. After the system is
hydrostatically tested and drained, the
Accelerator connection to the system
must be independently drained
through the Strainer clean-out plug by
first removing the Strainer clean-out
plug and then opening the Accelerator
Control Valve to vent the line.
Setting
Procedure
The Model ACC-1 Accelerator and Dry
Pipe Valve must be reset and restored
to service as soon as possible after an
operation. Follow the procedure indi-
cated below.
Step 1. Close the system main control
valve, the air supply control valve (to
the system) and the Accelerator Con-
trol Valve.
Step 2. Open the Inspector’s Test
Connection and then open the main
drain valve as well as all auxiliary (low
point) drains.
Step 3. After the system has been
drained, close the Inspector’s Test
Connection and all auxiliary drain
valves. Leave the main drain valve
open.
Step 4. Set the dry pipe valve in ac-
cordance with the instructions given in
the appropriate technical data sheet.
Restore normal system air pressure.
Leave the main control valve closed
and the main drain valve open.
Step 5. While holding the plunger of
the dry pipe valve’s automatic drain
valve depressed, partially open the
Accelerator Control Valve, and allow
the water in the Accelerator piping to
blow out. After water spray stops dis-
charging, close the Accelerator Con-
trol Valve and then release the
plunger. (
This instruction does not ap-
ply when the Model ACC-1 Accelera-
tor is being set for the first time, since
the Accelerator is shipped in the set
position. Proceed to Step 6.
)
Step 6. Clean out the Strainer at the
Accelerator Inlet.
NOTE
A clogged strainer can prevent the Ac-
celerator from properly tripping the dry
pipe valve.
Step 7. Slowly remove the Vent Plug
located in the front of the Accelerator
Cover and bleed off any residual air
pressure in the Differential Chamber.
Step 8. Unscrew (counter-clockwise
rotation) the knurled Reset Knob at the
front of the Accelerator until it resists
further turning. A click, which is the
sound of the Lever snapping back into
the Set Position, may be heard. Screw
theResetKnobbackinuntilitisfinger
tight.
NOTE
Do not wrench on the reset Knob,
since damage may result. The Reset
Knob will turn with finger torque only.
Step 9. Replace the Vent Plug.
Step 10. Verify that the system air
pressure has returned to normal.
Step 11. Partially open the Accelera-
tor Control Valve just enough to allow
air to slowly pass through the Accel-
erator Control Valve.
Using a watch, note the time for the
pressure in the Differential Chamber
of the Accelerator to increase to 10
psi. The time should be within the
range of values indicated in Table A
for optimum performance of the Accel-
erator.
NOTE
If the time to pressurize the Differential
Chamber to 10 psi is not within the
range of values given in the Table A,
then the Accelerator control Valve
should be closed and the corrective
procedure described in the Care and
Maintenance Section followed.
Step 12. When the air pressure in the
Page6of10
TFP1112
Pressure, psi Minimum, sec. Maximum, sec.
20 24 160
25 18 116
30 15 92
40 10 60
50 8 48
60 6 36
TABLE A
DIFFERENTIAL CHAMBER FILL TIMES TO 10 PSI
To Next Page
Loading...
Need help?
General
