Reliable EX Series User manual

Features
• Redundant Solenoid Valve Release
• Externally Resetable Clapper
• One Main Drain
Product Description
Reliable Single Interlock Preaction Systems are designed for
water-sensitive areas that require protection from inadvertent
water flow into the sprinkler system piping. A single event, the
activation of the electrical detection system, causes the valve to
operate and flow water into the piping network.
Sprinkler piping in single interlock systems can effectively
be supervised by means of the Reliable Model A Pressure
Maintenance Device (provided) and a tank-mounted air
compressor. Loss of supervising pneumatic pressure, due to
a damaged sprinkler or sprinkler pipe will not cause water to
flow through the Model EX Valve and into the system piping. A
signicant loss of pneumatic pressure will activate a trouble-
annunciating device when the system pressure falls below a
predetermined pressure level.
The system incorporates two normally closed solenoid valves on
the releasing trim. These solenoid valves, when closed, retain
sufcient AIR pressure on the pneumatic actuator, which in turn
preserves sufcient WATER pressure in the push rod chamber
of the Model EX Valve in order to maintain it closed. When the
electrical detection system senses the presence of re, the
electrical releasing control panel activates re alarm devices and
energizes the two redundant, normally-closed solenoid valves into
the open position.
Energizing the solenoid valves relieves the air pressure on the
pneumatic actuator, thereby releasing the water pressure that it
was retaining. This in turn relieves the pressure in the push rod
chamber of the Model EX Valve. Venting the push rod chamber
will open the Model EX Valve and allow water to flow into the
sprinkler system.
Water flowing into the sprinkler system piping will simultaneously
produce water pressure that causes the transfer of contacts in
the pressure switch mounted in the trim. This pressure switch can
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electrically initiate the shutdown or startup of equipment, such as
computers or other second alarm devices. The flow of water into
the sprinkler system piping effectively converts the dry system
into a wet pipe system. In the event that the re subsequently
produces sufcient heat to operate a re sprinkler, water will flow
from that sprinkler, controlling or suppressing the re.
The major benets of a single interlock preaction system, when
compared with a wet pipe (deluge) system are as follows:
1. A re alarm sounds prior to the operation of a sprinkler,
which may enable extinguishing the re by handheld means
before the actual operation of any sprinklers and subsequent
water damage.
2. A trouble annunciator signals whenever the integrity of the
piping or sprinklers is accidentally or intentionally disturbed;
however, no water flow or water damage will occur at that
time.
3. Speedy detection and an early re alarm are provided by
re detectors, without the delay associated with water flow
detection in the event of a re. Note: with a wet pipe system,
the re alarm is delayed until after water has begun flowing
from an operated sprinkler.
Valve Size End Connection Approx. Shipping Weight
2" (50mm), 2-1/2" (65mm), 76mm &
3" (80mm) Groove/ Groove 44lbs (20kg)
4" (100mm)
Groove/ Groove
74lbs (34kg)Flange/ Groove
Flange/ Flange
6" (150mm) & 165mm
Groove/ Groove
105lbs (48kg)Flange/ Groove
Flange/ Flange
8” (200mm) Groove/Groove 158lbs (72kg)
Flange/Flange
Table A
Bulletin 739 January 2021
Bulletin 739 January 2021
Model EX Single Interlock
Preaction Type A (LPCB)
2”, 2-1/2”, 76mm, 3”, 4”, 6”, 165mm, & 8”
Availability: UK

Model EX Single Interlock Preaction System Type A Technical Data
Technical Specications
Pressure Rating:
175 psi (12,1 bar)
Minimum Water Supply Pressure:
20psi (1,4 bar)
Minimum Water Supply Temperature:
40°F (4°C)
Maximum Water Supply Temperature:
140°F (60°C)
Factory tested to hydrostatic pressure of 500 psi (34.5 bar)
Listings and Approvals
LPCB
End Connections
See Table A
Specications
Groove: ANSI/AWWA C606
Flange: ASME B 16.5 or ISO 7005-2 PN16
Thread: ANSI B1.20.1
Valve Size End
Connection A(1) A(2) B C D E F G H I
2" (50mm)
Groove/Groove 12-1/2
(318)
NA
5-1/2
(140)
31-1/2
(800)
4-1/4
(108)
14-1/2
(368)
9-7/8
(251)
7
(178)
8-1/2
(216)
8-3/8
(213)
2-1/2" (65mm)
NA
76mm
3" (80mm)
4" (100mm)
Groove/Groove 14
(356) 16
(406)
5-1/2
(130)
33-3/8
(848)
5-1/2
(140)
16
(406)
11
(279)
8
(203)
8-1/2
(216)
10
(254)
Flange/Groove 16
(406)
Flange/Flange
6" (150mm)
&
165mm
Groove/Groove 16
(406) 19
(483)
4-7/8
(124)
34-5/8
(880)
5-1/2
(140)
16-1/2
(419)
11-5/8
(295)
8-5/8
(219)
8-1/2
(216)
10-1/2
(267)
Flange/Groove 19
(483)
Flange/Flange
8" (200mm)
Groove/Groove 19-3/8
(492) 21-1/4
(540)
4-5/8
(117)
34-1/8
(867)
5-1/2
(140)
17
(432)
13-5/8
(346)
9-1/8
(232)
8-1/2
(216)
11-3/4
(298)
Flange/Flange 21-1/4
(540)
Installation Dimensions in Inches (mm) Table B
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Notes:
1. End to end take out of Model DDX valve with grooved inlet.
2. End to end take out of Model DDX valve with flanged inlet where available (see page 1, table A).
Model EX Type A Dimensions Figure 1

At the heart of Reliable’s Single Interlock Preaction System is the
Model EX Valve. This valve is a hydraulically operated, straight-
through-design, differential-type valve (see Fig. 2). System
maintenance is simplied since priming water is not required and the
deluge valve can be reset externally without cover removal. This is
accomplished by pushing in and turning the external reset knob at
the rear of the valve (see Fig. 2). This feature provides a signicant
system-restoration time advantage.
The Reliable Single Interlock Preaction System trim set (see Fig.
2) provides all of the necessary equipment for connections to the
valve’s pushrod chamber inlet and outlet ports, the main drain,
alarm devices, air supply, water supply, and required pressure
gauges. This valve is provided fully assembled with trim.
System Operation
To fully operate a Reliable Single Interlock Preaction System, two
independent events must coexist before water is discharged. One
electrical detector (two detectors in a cross-zoned system) must
activate and a sprinkler must open. Operation of the detection
system will cause the valve to open, but no water will discharge
since the sprinklers will not have opened. Opening of a sprinkler in
the absence of a detection signal will result in loss of air or nitrogen
pressure and activation of a low pressure alarm.
When set correctly for service, the Model EX Valve is hydraulically
established to withhold the supply water from the sprinkler system
piping. The Reliable Model EX Valve is shown in both closed and
open positions in Fig.2. In the closed position, the supply pressure
acts on the underside of the clapper and also on the push rod
through the push rod chamber’s inlet restriction. The resultant force
due to the supply pressure acting on the push rod is multiplied by
the mechanical advantage of the lever and is more than sufcient to
hold the clapper closed against normal supply pressure surges.
When a re is detected, the energized solenoid valves vent the
air from the pneumatic actuator, which in turn vents the push rod
chamber to atmosphere through the chamber’s outlet. Since
the pressure cannot be replenished through the inlet restriction
as rapidly as it is vented, the pushrod chamber pressure falls
instantaneously. When the pushrod chamber pressure approaches
approximately one-third of the supply pressure, the upward force
of the supply pressure acting beneath the clapper overcomes the
lever-applied force thereby opening the clapper.
Once the clapper has opened, the lever acts as a latch, preventing
the clapper from returning to the closed position. Water from the
supply flows through the EX Valve into the system piping. Water also
flows through the dry pipe alarm outlet to the alarm devices.
After the system is shut down and drained, the Model EX valve can
be reset by pushing in and turning the reset knob at the rear of the
valve (see Fig.2). The external reset feature of the Model EX Valve
provides a means for simple, economical system testing, which is
one essential facet of a good maintenance program.
The external reset feature does not, however, eliminate another
important facet of good maintenance, namely, periodic cleaning and
inspection of the internal valve parts. In the event that water builds
up inside the valve due to condensate from the air supply system
or water left inside from valve system testing, a drain is available
for venting. After closing the main supply valve, a small valve over
the drain cup can be opened slightly until the water inside the valve
body and the main pipe column has drained. See the section titled
“Draining Excess/Condensate Water From System” in this bulletin for
the detailed procedure.
The Model B Manual Emergency Station is also included in the trim
set. It consists of an aluminum nameplate mechanically attached to
a ball valve. The valve handle in its OFF position is guarded against
accidental turning to the ON position (and system discharge) by a
nylon cable tie provided with each trim kit. The cable tie is inserted,
after the system has been restored for operation. The nylon cable
tie is designed to allow, in case of an emergency, forceful turning of
the valve handle to the ON position. As an alternative to the Model B
Hydraulic Manual Emergency Station, the Model A Hydraulic Manual
Emergency Pull Box (see Reliable Bulletin 506) is also available and
can be provided as an option.
Whenever ambient temperature conditions are high, the water
temperature in the Model EX Valve’s pushrod chamber could
possibly increase, thereby increasing the pressure in the chamber to
values exceeding the rated pressure of the system. In an installation
where standard temperatures are exceeded, a pressure relief kit may
be needed. Pressure relief kit, P/N 6503050001, can be installed
into the pushrod chamber’s releasing line to limit the pressure to 175
psi (12,1 bar).
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January 2021
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Model EX Type A Section and Rear Views Figure 2

System Design Considerations
The automatic sprinklers, air compressor, releasing devices,
electric releasing control equipment, re detection devices, manual
pull stations, and signaling devices which are utilized with this
Reliable Single Interlock Preaction System must be Loss Prevention
Certication Board (LPCB) approved, as applicable.
The system valve and all interconnecting piping must be located in
a readily visible and accessible location and in an area that can be
maintained at a minimum temperature of 40°F (4°C). Note: Heat
tracing is not permitted.
The redundant solenoid valves are operated and supervised by an
electrical releasing/control panel.
System Air Pressure Requirements
When a Reliable Single Interlock Preaction System is utilized,
the sprinkler system piping requires a minimum of 7 psi (0,5
bar) supervisory pneumatic pressure. The Model A Pressure
Maintenance Device, along with an additional air pressure regulator,
are used to maintain the system pneumatic pressure between 7 and
10 psi (0,5 and 0,7 bar) where a dry nitrogen gas supply or a clean,
dependable, and continuous (24 hours per day, 7 days per week)
compressed air source is available.
The section of the preaction trim that contains the two redundant
normally-closed solenoid valves, and the supply to the pneumatic
actuator require pneumatic pressure settings per Table C. When
establishing the preaction system for service, refer to Table C
of this bulletin for the correct pneumatic pressure settings for a
corresponding water supply pressure.
Note: During the initial system set-up, a higher pneumatic pressure
may be required in order to properly seat the internal diaphragm of
the pneumatic actuator.
Refer to Reliable Bulletin 251 for instructions on how to modify these
pressure settings.
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Water Pressure
psi (bar)
Pneumatic Pressure to be Pumped
into Sprinkler System, psi (bar)
Maximum Not Less Than Not More Than
20 (1.4) 10 (0.7) 14 (0.9)
50 (3.4) 12 (0.8) 16 (1.1)
75 (5.2) 13 (0.9) 17 (1.2)
100 (6.9) 15 (1.0) 19 (1.3)
125 (8.6) 16 (1.1) 20 (1.4)
150 (10.3) 17 (1.2) 21 (1.4)
175 (12.1) 18 (1.2) 22 (1.5)
System Pressure Table C
System Electrical Requirements
All releasing, alarm and detection devices in this Reliable Single
Interlock Preaction System are supervised by the Preaction Panel
Series 1000 MK4. The power supply, the standby emergency
power supply, battery charger, and the rectier circuitry are all
contained within this panel. For additional and detailed wiring
information, refer to the manufacturer’s literature included with the
Releasing Control Panel.
Note: In order for the solenoid valve to maintain Reliable warranty
it must remain sealed as it came from the factory. If there are
concerns about the valve’s internal components, immediate
replacement is recommended.
Valve Size: Equivalent Length: Cv
C = 120 C = 100
2" (50mm) 4.4 ft (1,3 m) 3.1 ft (1,0 m) 101
2-1/2" (65mm) 6.0 ft (1,8 m) 4.3 ft (1,3 m) 236
76mm 7.7 ft (2,3 m) 5.5 ft (1,7 m) 241
3" (80mm) 12.6 ft (3,8 m) 9.0 ft (2,7 m) 254
4" (100mm) 14 ft (4,3 m) 10 ft (3,0 m) 469
165mm 29.4 ft (9,0 m) 20.9 ft (6,4 m) 886
6" (150mm) 29.4 ft (9,0 m) 20.9 ft (6,4 m) 886
8" (200mm) 53.5 ft (16,3 m) 38.1 ft (11,6 m) 1516
Friction Loss Table D

Single Interlock Preaction System Air Pressure Settings Figure 3
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Bulletin 739
January 2021
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Resetting the Model EX Single Interlock
System (Ref. Fig. 5)
1. Close the valve controlling water supply to the Model EX Valve
and close the air or nitrogen supply to the sprinkler system.
2. Close the pushrod chamber supply valve.
3. Open main drain valve and drain system. Close main drain
valve.
4. Open all drain valves and vents at low points throughout the
system, closing them when flow of water has stopped.
5. Open the Manual Emergency Station to relieve pressure in
the pushrod chamber of the Model EX Valve.
6. With the alarm line valve open, push in the plunger of ball drip
valve, forcing the ball from its seat, and drain the alarm line.
Close the alarm line valve.
7. With the Manual Emergency Station open, push in and rotate
the Model EX Valve external reset knob counterclockwise
(when facing the valve), until you hear a distinct noise
indicating that the clapper has reset. Note: The reset knob
can be rotated only while pressure in the pushrod chamber is
vented to atmospheric condition (0 psig) in step 5.
8. Inspect and replace any portion of the detection system and/
or sprinkler system subjected to re conditions.
9. Conrm that solenoid valves are de-energized and closed.
10. Open the air or nitrogen supply quick ll valve to restore
supervisory pressure in the sprinkler system and close
the pneumatic actuator. Allow the pressure to build to the
level specied in Table A, then set the pneumatic supply to
automatic operation.
11. Open the main drain approximately two turns.
12. Open the pushrod chamber supply valve.
13. Slightly open the main control valve until water can just be
heard running out the main drain.
14. Slowly close the main drain, directing water to the Manual
Emergency Release. Allow water to flow through the Manual
Emergency release to purge air from the pushrod chamber.
Note: Venting of air from the pushrod chamber is very
important to ensure proper system operation and avoid false
tripping of the Model EX Valve.
15. Upon seeing a solid flow of water from the drain tubing, close
the Manual Emergency Release valve. Allow pressure to build
below the Model EX Valve clapper.
16. Open the alarm line valve. If no leak occurs, the Model EX
Valve clapper is sealed.
17. Slowly open the main valve controlling water supply until fully
open and verify that it is properly monitored.
18. Verify that the pushrod chamber supply valve and alarm line
valve are open. The pushrod chamber supply valve must
remain open when the Model EX Valve has been reset to
maintain water pressure in the pushrod chamber.
19. Verify that the Manual Emergency Station is secured in the
OFF position with the appropriate nylon tie.
Model EX Type A Components Figure 4

Inspection and Testing
1. Water supply — Conrm that valves controlling water supply
to the EX Valve are opened fully and properly monitored.
2. Alarm line — Conrm that the alarm line valve is open and
remains in this position.
3. Other trim valves — Conrm that the pushrod chamber
supply valve is open, as well as all pressure gauge valves.
The main drain valve, condensate drain valve, and alarm test
valve should be closed.
4. Ball drip valve — Push in on the plunger to be sure ball check
is off its seat. If no water appears, the Model EX Valve water
seat is tight. Inspect the bleed hole on the underside of the
pushrod chamber for leakage.
5. Supervisory pneumatic pressure — Inspect actuation piping
and system air (or nitrogen) pressure for conformance to
Table A.
6. Releasing device — Check outlet of the releasing devices
(i.e., hydraulic manual emergency station and solenoids)
for leakage. Also verify that tubing drain lines from releasing
devices are not pinched or crushed which could prevent
proper releasing of the EX Valve.
7. Testing alarms — Open the alarm test valve permitting water
from the supply to flow to the electric sprinkler alarm switch
and to the mechanical sprinkler alarm (water motor). After
testing, close this valve securely. Push in on the plunger of
ball drip valve until all water has drained from the alarm line.
8. Operational test — Open the Model B Manual Emergency
Station. Alternatively, deplete pneumatic pressure from
the sprinkler system. Note: AN OPERATIONAL TEST WILL
CAUSE THE MODEL EX VALVE TO OPEN AND FLOW
WATER INTO THE SPRINKLER SYSTEM.
9. Secure the Model B Manual Emergency Station in the OFF
position with nylon tie after EX Valve is reset.
Testing Detection System Without Operating
Model EX Valve
1. Close the valve controlling water supply to the system valve
and open the main drain valve.
2. Verify that valve supplying hydraulic pressure to the piston/
pushrod chamber is open, allowing water to enter the pushrod
chamber.
3. Deplete pneumatic pressure from the sprinkler system.
4. Loss of pneumatic pressure must result in a sudden drop of
water pressure in the pushrod chamber, as indicated by the
pressure gauge on the hydraulic release trim.
5. Reset the valve per the reset instructions.
Maintenance
The owner is responsible for maintaining the re protection system
in proper operating condition. Any system maintenance or testing
that involves placing a control valve or detection/control system out
of service may eliminate the re protection that is provided by the re
protection system.
The Reliable Model EX valve and associated equipment shall
periodically be given a thorough inspection and test. NFPA 25,
“Inspection, Testing, and Maintenance of Water Based Fire Protection
Systems,” provides minimum maintenance requirements. System
components shall be tested, operated, cleaned, and inspected
7.
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at least annually, and parts replaced as required. Replace any
components found to be corroded, damaged, worn, or non-operable.
Increase the frequency of inspections when the valve is exposed
to corrosive conditions or chemicals that could impact materials or
operation of the assembly.
If face plate is removed during maintenance, torque face plate bolts
to the following values during re-installation:
• 35 ft-lbs. (47 N-m) for 2” through 4” valves
• 70 ft-lbs. (95 N-m) for 6”-8” valves
Draining Excess/Condensate Water from the System
1. Notify the owner and monitoring company that maintenance is
being performed on the system.
2. Close the main water control valve.
3. Open the Main Drain Valve.
4. Open the Condensate Drain Valve until all water has drained.
5. Close Condensate Drain Valve.
6. Partially open the Main Water Control Valve.
7. Slowly close the Main Drain Valve.
8. Fully open the Main Water Control Valve.
9. Notify the owner and monitoring company that the system has
been returned to service.
Clapper Gasket and Seat Replacement Procedure
1. Disable detection system and supervisory pneumatic supply
to system.
2. Shut down the valve controlling the water supply to the system
and open the main drain valve. Open the condensate drain
valve. Close the pushrod chamber supply valve and open the
Model B Manual Emergency Station.
3. Remove the EX Valve front (handhold) cover and inspect the
seat, clapper, and seal assembly for damage. If inspection
indicates damage to the seal assembly only, replace as
follows:
4. Remove the bumpstop nuts and remove the seal assembly
. Install a new seal assembly and thread the bumpstop nuts
onto the threaded studs of the seal assembly. Tighten nger
tight plus ¼ to ½ turn.
5. If inspection indicates damage to the clapper, proceed to step
6.
6. At the rear of the valve, disconnect the condensate drain
trim section starting with the elbow connector. Then remove
the ¼” globe valve, followed by the ¾”x¼” reducing bushing.
Remove the retaining rings from the clapper hinge pin, push
the hinge through the condensate drain opening and remove
the clapper subassembly. Install a new clapper subassembly
in the reverse order making sure the clapper spacers are in
their proper position.
7. If the seat is damage, or it is suspected that the leakage is
through the seat O-rings, proceed to step 8.
8. Using Reliable P/N 6881603000 Seat Wrench for 2” (50mm),
2½” (65mm), 76mm and 3” (80mm) valve sizes, Reliable
P/N 6881604000 for 4” (100mm) valve size, Reliable P/N
6881606000 for the 6” (150mm) and 165mm valve sizes or
Reliable P/N 6881608000 Seat Wrench for 8” (200mm) valve
size, remove the seat by unscrewing. This will loosen the seat-
clapper-mounting ring subassembly.

8.
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Solenoid Valve
WARNING: The owner is responsible for maintaining the
re protection system in proper operating condition. Any
system maintenance or testing that involves placing a control
valve or detection system out of service may eliminate the
re protection of that system. Prior to proceeding, notify
all authorities having jurisdiction. Consideration should be
given to employment of a re patrol in the affected area.
WARNING: Prior to operating the solenoid valve, be sure to close the
system control valve to avoid unintentional operation of the system.
1. Inspections: It is imperative that the system be inspected
and tested in accordance with NFPA 25 on a regular
basis. The frequency of the inspections may vary due to
contaminated water supplies, corrosive water supplies,
or corrosive atmospheres. In addition, the alarm devices,
detection systems, or other connected trim may require a
more frequent schedule. Refer to the system description
and applicable codes for minimum requirements.
2. The valve must be inspected at least monthly for cracks,
corrosion, leakage, etc., cleaned and replaced as necessary.
3. If leakage is suspected through the solenoid
valve, it should be replaced.
Troubleshooting
1. Mechanical sprinkler alarm not operating: This is most
likely caused by a clogged screen in the strainer of the water
motor. Proceed as follows: Remove plug from the strainer.
Remove and clean the screen. Replace the screen and
the plug, and then tighten securely (Ref. Bulletin 613).
2. Water leaking from Ball Drip. This can be
caused by either a water column on top of
the clapper or a supply water leakage.
a. Leakage due to water column. This condition is
caused by leakage past the clapper seal assembly. Be
sure the clapper seal and seat are free of any type of
debris or damage. If necessary, follow steps below to
replace the seal assembly and/or seat.
b. Supply water leakage. This condition is caused by
leakage past the lower seat O-ring. Follow steps below for
inspection and/or replacement of lower seat O-ring.
3. Air or nitrogen leaking from Ball Drip. This
condition is caused by leakage past either the
clapper seal assembly or the upper seat O-ring.
a. Clapper seal leak. Be sure the clapper seal and seat
are free of any type of debris or damage. If necessary,
follow steps below to replace the seal assembly and/or
seat.
b. Upper seat O-ring. Follow steps below for inspection
and/or replacement of upper seat O-ring.
Clapper Gasket and Seat Replacement Procedure (cont.)
8 (cont). Reach into the valve and grasp the seat and remove
it from the valve. Then remove the clapper-mounting ring
subassembly from the valve. Visually examine all components
of the seat-clapper-mounting ring subassembly replacing
any component that appears damaged. New O-rings should
always be used for reassembly.
9. Reassembly: clean the bore of the valve body. Lubricate the
bore with O-ring grease. Lubricate and install the O-rings onto
the seat. Lubricate and install the mounting ring O-ring into the
body (8” (200mm) valve size only). Insert the clapper-mounting
ring subassembly into the handhold opening of the EX Valve
using caution to not damage or dislodge the mounting ring
O-ring (8” (200mm) valve size only). Align the mounting ring
so that the Lever is near the pushrod and the mounting ring
“ears” are between the tabs of the valve body. Insert the seat
into the valve body and through the clapper-mounting ring
subassembly. Start to tread the seat into the body by hand,
then tighten the seat with the seat wrench until it bottoms out
on the mounting ring. Verify that the seat-clapper-mounting
ring subassembly is in the fully down position between the
tabs of the body, and check to see that the lever lines up with
the pushrod. Reassemble the handhold cover and set up the
Model EX Valve as per the section “Resetting Model EX Valve
Single Interlock Preaction Systems”.
Pushrod Chamber Diaphragm and O-Ring Replacement
Procedure
A small bleed hole is located on the underside of the pushrod
chamber. If there is air or water leakage coming out of the bleed
hole:
a. Disable detection system and supervisory pneumatic supply
to system.
b. Shut down the valve controlling water supply to the system.
Relieve the inlet pressure by opening the main drain valve.
Close the valve that supplies water to the pushrod chamber,
and open the Model B Manual Emergency Station.
c. Remove the trim at the unions nearest to the pushrod chamber
cover.
d. Take the pushrod chamber cover off by removing the six
retaining screws.
CONDITION ONE (Water coming out of the bleed
hole):
Water coming out of the bleed hole is caused by a leaking
diaphragm. Visually inspect the pushrod chamber cover and
piston to determine what could have damaged the diaphragm and
then correct. Install a new diaphragm. NOTE: The diaphragm has
two different surfaces; it is not bi-directional. It will fail if installed
backwards! Roll the diaphragm so that the smooth surface (the
pressure side) conforms to the inside of the pushrod chamber
cover and the fabric side engages the pushrod, and reassemble
the six retaining screws with an installation torque of 15 foot-pounds
in a star pattern. Set up the Model EX Valve as per the section
“Resetting Model EX Valve Single Interlock Preaction Systems”.

CONDITION TWO (System Air coming out of the
bleed hole):
System air coming out of the bleed hole is caused by a worn O-ring
assembled to the pushrod guide. Remove the piston-pushrod
subassembly, pushrod spring, and pushrod guide. installation
torque for the pushrod guide is 35 inch-pounds. CAUTION: Do
not over tighten the pushrod guide. Reassemble the components
that were initially removed. Re-install the diaphragm if it appears
to be in good shape, otherwise, replace it also. NOTE: The
diaphragm has two different surfaces; it is not bi-directional. It will
fail if installed backwards! Roll the diaphragm so that the smooth
surface (the pressure side) conforms to the inside of the pushrod
chamber cover and the fabric side engages the pushrod, and
reassemble the six retaining screws with an installation torque of
15 foot-pounds in a star pattern. Set up the Model EX Valve as per
the section “Resetting Model EX Valve Single Interlock Preaction
Systems”.
Listing & Approvals
The LPCB approval for Single Interlock Preaction systems states
the system must comply with the general requirements of the
“LPC Rules for Automatic Sprinkler Systems (incorporating
EN12845)” and in particular Technical Bulletin 208 “Supplemen-
tary requirements for sprinkler installations which can operate in
the dry mode”.
Loss Prevention Certication Board (LPCB)
Installation Requirements of Preaction Systems Include:
1. The equipment must be installed, congured and maintained
in accordance with the manufacturers specications, by
appropriately trained personnel.
2. The system shall be electrically monitored and be capable of
indicating “ready to operate” at all times.
3. Detectors should be LPCB approved and must be compatible
with the Control Panel.
4. Connecting cables shall comply with BS6387 (classication
C, W, Z).
5. Two LPCB approved Solenoid Valves shall be installed in
parallel, shall function in the pneumatic condition only and be
protected by a strainer.
6. Clean dry air (or Nitrogen) shall be used. An air maintenance
device shall be used, such that the inflow of air cannot
exceed the egress of air through one sprinkler, or any other
means of operating the valve.
Ordering Information
Specify:
Model EX Single Interlock Preaction System Type A
• Size
• 2” (50mm)
• 2-1/2” (65mm)
• 3” (80mm)
• 76mm
• 4” (100mm)
• 6” (150mm)
• 165mm
• 8” (200mm)
• End Conguration
• See Table A
Service Kits
Service kits are available for routine servicing of the valve (refer-
ence assembly drawings on website). Service kits for the Model
EX Single Interlock Preaction Type A valve include the following
components:
• Clapper Seal Assembly (item 8)
• Cover Gasket (item 9)
• Bumpstop(s) (item 10)
• Push rod chamber diaphragm (item 18)
• Pneumatic Actuator Diaphragm Assembly (items 41, 42, 43,
and 44)
• Grease (item 50)
2”, 2-1/2”, & 3” Model EX Service Kit: PN 6501200R09
4” Model EX Service Kit: PN 6501200R10
6” Model EX Service Kit: PN 6501200R11
8” Model EX Service Kit: PN 6501200R12
9.
Bulletin 739
January 2021
Page 9 of 9
www.reliablesprinkler.com