Reliable Single Interlock Preaction System Instructions For Installation Manual

Instructions for
Installation, Operation
Care and Maintenance

For Single Interlock Preaction Systems
With Dual Solenoid Actuation
Of Pneumatic Pilot Release

Bulletin 739

Single Interlock
Preaction System

4"(100mm),
6"(150mm) & 165mm
Sizes with Trim

LPCB Approved

•

Redundant Solenoid Valve

•

Release

Rated to 175 psi (12.1 bar)

•

Externally Resetable

•

Clapper
One Main Drain

•

Bulletin 739

The Reliable Automatic Sprinkler Co., Inc., 103 Fairview Park Drive, Elmsford, New York 10523

General Description

Reliable Single Interlock Preaction Systems are de
signed for water-sensitive areas that require protection
from inadvertent water flow into the sprinkler system pip
ing.

Sprinkler piping in single interlock systems can effec
tively be supervised by means of a Reliable Model A-2

Pressure Maintenance Device 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 DDX Deluge
Valve and into the system piping. A significant loss of
pneumatic pressure will activate a trouble-annunciating
device when the system pressure falls below a predeter
mined pressure level.

When one electrical detector senses the presence of
fire, the electrical releasing control panel activates fire
alarm devices and energizes the two redundant, nor
mally-closed solenoid valves in the open position (
Arranging detectors in a cross-zoned pattern will require
operation of two detectors before the solenoid valves
can open). These solenoid valves, when closed, retain
sufficient AIR pressure in the Model LP Pilot Line Actua
tor, which in turn preserves sufficient WATER pressure in
the push rod chamber of the Model DDX Deluge Valve in
order to maintain it closed.

Energizing the solenoid valves relieves the air pressure
in the Model LP Dry Valve Actuator (see Fig. 8), thereby
releasing the water pressure that it was retaining. This is
turn relieves the pressure in the push rod chamber of the
Model DDX Deluge Valve. Venting this push rod cham­ber will open the Model DDX Deluge Valve and allow wa­ter to flow into the sprinkler system.

To fully operate a cross-zoned single interlock system,

two electrical detectors must activate and a sprinkler
head must open. During the early stages of a fire, smoke
or heat activates the first detector, which causes the con­trol panel to produce a local alarm and an alarm at the
main fire alarm panel. Electrical relays inside the releas
ing control panel can be used to shut down airmoving
equipment or activate security doors and other electrical
devices. Subsequent activation of a second, nearby or
adjacent detector will cause the panel to energize the
solenoid valves open and release water into the sprinkler
system piping. 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 pressureswitch can electrically
initiate the shutdown or startup of equipment, such as
computers or other second alarm devices. This flow of
water into the sprinkler system piping effectively con
verts the dry system into a wet pipe system. In the event
that the fire subsequently produces sufficient heat to op
erate a sprinkler head, water will flow from that sprinkler,
controlling or suppressing the fire.

The major benefits of a single interlock preaction sys
tem, when compared with a wet pipe (deluge) system
are as follows:

Note:

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A. A fire alarm sounds prior to the operation of a
sprinkler head, which may enable extinguishing
the fire by handheld means before the actual oper
ation of any sprinklers and subsequent water dam
age.

B. A trouble annunciator signals whenever the in

tegrity of the piping or sprinklers is accidentally or
intentionally disturbed; however, no water flow or
water damage will occur at that time.

C. Speedy detection and an early fire alarm are

provided by fire detectors, without the delay asso
ciated with water delivery time in the event of a fire.

with a wet pipe system, the fire alarm is de

Note:

layed until after water has begun flowing from an
operated sprinkler head.

At the heart of Reliable’s Single Interlock Preaction Sys
tem is the Model DDX DelugeValve. This Deluge Valve is
a hydraulically operated, straight-through-design, differ
ential-type valve (see Fig. 1). System maintenance is
simplified since priming water is not required and the
deluge valve can be reset externally without cover re
moval. This is accomplished by pushing in and turning
the external reset knob at the rear of the deluge valve
(see Fig. 1). This feature provides a significant 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 Model DDX Deluge Valve’s pushrod
chamber inlet and outlet ports, the 2” (50mm) main
drain, alarm devices, air supply, water supply, and re­quired pressure gauges. This trim set is available in indi­vidual parts, in time-saving, segmentally assembled kit
forms, or fully assembled to the Model DDX Deluge
Valve.

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Listing & Approvals

The 4” (100mm), 6’ (150mm) and 165mm Single Inter

lock Preaction Systems shown in this bulletin must only
be used in the combination described herein to be Loss
Prevention Certification Board (LPCB) approved. Instal
lation of these systems must be according the require
ments of Technical Bulletin TB21:1994:1.

The majority of the system’s components are individu

ally Listed by Underwriters Laboratories Inc. and Fac
tory Mutual Approved.

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2.

Loss Prevention Certification Board
(LPCB) Installation Requirements of
Preaction systems Include:

1. Solenoid valves shall be installed in parallel.

2. Solenoid valves shall function in pneumatic condi

tions only, and be protected by a strainer.

3. LPCB Certified detectors compatible with the control

and indicating equipment shall be used.

4. Suitable electrical detection, control and indicating

equipment and pneumatic systems shall be used.
The control and indicating equipment shall be LPCB
approved / certificated.

5. Connecting cables shall comply with BS 6387:1983,

classification C, W, Z evidenced by LPCB certifica
tion.

6. Pre-action systems shall be electrically monitored to

demonstrate that they are in a ‘ready to operate’
state at all times.

7. Clear dry air shall be used. Compressor tank must

have provision for draining.

8. Pre-action system equipment shall be installed, oper

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ated and maintained as prescribed in the firm’s instal
lation , operating and maintenance manual.

9. Pre-action systems shall be configured in accordance

with the manufacturer’s defined specifications.

10.Pre-action systems shall comply with the details spec

ified in the relatedLPC Technical Bulletin (Ref. TB21).

11.The firm responsible for the complete pre-action sta

tion, including electrics, shall be identified.

12.Normally un-energized solenoids may be used, pro

vided that they are continuously monitored for ‘open’
and ‘short circuit.’

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Fig. 1

3.

Fig. 2

3.

SINGLE INTERLOCK PREACTION SYSTEM PARTS LIST (REFER TO FIG. 2)

ITEM

NO.

1

2 78653004

3 98048000

4 98048015

5 98048022

6 98048025

7 92056809

8 92056810

9 92056811

10 92056702

11 92056704

12 98085666

13 98050004

14 98174400

15 98174403

16 98174401

17 98174404

18 98174405

19 98174402

20 96920912

21 98240006

22 98240101

23 6304000100

24 78653000

25 71030010

26 94616917

27 98543222

28 98543266

29 98543213

30 98543223

31 98543210

32 98543216

33 98543209

34 98543230

35 98543237

36 98543226

PART

NUMBER

6103040026

6103060028

DESCRIPTION

MODEL DDX VALVE,
ASSEMBLY, 4" (100MM)

MODEL DDX VALVE,
ASSEMBLY, 6" (150MM)

MODEL DDX VALVE,
ASSEMBLY, 165 MM

ASSEMBLY, VALVE CAUTION
STATION, 1/2"

BUSHING, REDUCER,
1/2" x 1/4", GALV.

BUSHING, REDUCER,
2" SPIGOT x 1" NPTF, PVC

BUSHING, REDUCER,
3/4" X 1/2", GALV.

BUSHING, REDUCER,
3/4" X 1/4", GALV.

CONNECTOR ASSEMBLY,
NO-LOSS, 3/8 x 1/2 NPT

CONNECTOR,
3/8" ID TUBE x 1/2" NPT

CONNECTOR,
3/8" ID TUBE x 1/4" NPT

CONNECTOR,
3/8" TUBING x 1/4" NPT

CONNECTOR, ELBOW,
3/8" ID TUBE x 1/2" NPT

REDUCER, 1/2" x 1/4"

DRAIN CUP, PVC

ELBOW, STREET, 1/2"

ELL, 1"

ELL, 1/2"

ELL, 1/4"

ELL, 2"

ELL, 3/4"

FLEX LINE, 12"

GAUGE, WATER PRESSURE
(16 BAR) W/ CONNECTOR

GAUGE, WATER PRESSURE
(6 BAR) W/ CONNECTOR

MOD. A-2 AUTO AIR
MAINTENANCE DEVICE, 10PSI

MODEL B MANUAL
EMERGENCY STATION

MODEL LP
DRY VALVE ACTUATOR

NAMEPLATE,
SINGLE INTERLOCK

NIPPLE, STEEL, 1" X 3-1/2"

NIPPLE, STEEL, 1" X 6"

NIPPLE, STEEL, 1" X CLOSE

NIPPLE, STEEL, 1/2" X 1-1/2"

NIPPLE, STEEL, 1/2" X 2-1/2"

NIPPLE, STEEL, 1/2" X 3-1/2"

NIPPLE, STEEL, 1/2" X 2"

NIPPLE, STEEL, 1/2" X 3"

NIPPLE, STEEL, 1/2" X 8"

NIPPLE, STEEL, 1/4" X 1-1/2"

NO

REQ'D

16103060024

1

4

1

1

2

1

1

1

1

1

4

1

1

1

1

1

1

2

1

2

2

1

1

1

1

1

1

1

17

1

1

2

1

1

21

ITEM

NO.

37 98543225

38 98543244

39 98543220

40 98543243

41 98543227

42 98543208

43 98543238

44 98543215

45 98543233

46 98543232

47 98543279

48 99080002

49 98750003

50 98604406

51 98614403

52 98614401

53 98681630

54 78650201

55 98727607

56 96556922

57 96606627

58 96606607

59 98761649

60 98761651

61 96606608

62 96606612

63 96606601

64 89141112

65 98815204

66 98815200

67 98815201

68 98815202

69 98840160

70 98840101

71 98840100

72 78653100

73 98840110

74 98840144

75 98840145

76 98840181

77 98840171

78 6871020010

79 6871020000

80 98840193

81 96686722

82 96686756

PART

NUMBER

DESCRIPTION

NIPPLE, STEEL, 1/4" X 2-1/2"

NIPPLE, STEEL, 1/4" X 2"

NIPPLE, STEEL, 1/4" X 3"

NIPPLE, STEEL, 1/4" X 4"

NIPPLE, STEEL, 1/4" X CLOSE

NIPPLE, STEEL, 2" X 3"

NIPPLE, STEEL, 2" X CLOSE

NIPPLE, STEEL, 3/4" X 1-1/2"

NIPPLE, STEEL, 3/4" X 2-1/2"

NIPPLE, STEEL, 3/4" X 2"

NIPPLE, STEEL, 3/4" X CLOSE

PAD-ADHESIVE

PIPE CROSS, 1/2"

PLUG, SQ. HD., 1/2"

PLUG, SQ. HD., 1/4"

PLUG, SQ. HD., 3/4"

REGULATOR, AIR LINE

STRAINER, 1/2" NPT

STRAINER, 1/4"

SWITCH, PRESSURE,
BAILEY & MACKEY

TEE, GLVN, 2 X 2 X 1

TEE, GLVN., 1/2 X 1/2 X 1/4

TEE, GLVN., 1/2 X 1/4 X 1/2

TEE, GLVN., 1/2"

TEE, GLVN., 1/4 X 1/4 X 1/4

TEE, GLVN., 3/4 X 1/2 X 1/2

TEE, GLVN., 3/4"

TIE, RETAINING

UNION, "O" RING SEAL, 1/2"

UNION, 1/2", IRON, G.J., GALV.

UNION, 1/4", IRON, G.J., GALV.

UNION, 3/4", IRON, G.J., GALV.

VALVE, 3-WAY, 1/4"

VALVE, ANGLE, 1/4"

VALVE, ANGLE, 2"

VALVE, BALL DRIP, 1/2"

VALVE, BALL, 1/4"

VALVE, CHECK GAUGE

VALVE, CHECK, 1"

VALVE, CHECK, 1/2"

VALVE, GLOBE, 1/2"

VALVE, SOLENOID ASCO

VALVE, SOLENOID SKINNER

VALVE, SPRING CHECK, 1/4"

TUBING, COPPER,
3/8" O.D. X 2 FT

TUBING,PVC,3/8"I.D.x6FT

NO

REQ'D

1

1

2

1

1

2

1

1

1

1

3

1

2

1

5

3

1

1

1

1

1

1

2

2

3

1

2

3

1

2

3

1

4

1

1

1

1

2

1

1

1

1

1

2

1

1

3.

Fig. 3

System Operation

To fully operate a Reliable Single Interlock Preaction Sys­tem, two independent events must coexist beforewater flow
will occur. One electrical detector (two detectors in a
cross-zoned system) must activate and a sprinkler head
must open. Operation of either one of these items will only
cause an alarm to annunciate, but will not cause water to
discharge from the sprinkler system piping.

When set correctly for service, the Model DDX Deluge

Valve is hydraulically established to withhold the supply wa
ter from the sprinkler system piping. The Reliable Model
DDX Deluge Valve is shown in both closed and open posi
tions in Fig.1. 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 re
sultant force due to the supply pressure acting on the push
rod is multiplied by the mechanical advantage of the lever
and is more than sufficient to hold the clapper closed
against normal supply pressure surges.

When a fire is detected, the energized solenoid valves vent

the air from the Model LP Dry Valve Actuator (see Fig. 8),
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 instanta
neously. 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 deluge valve into the system piping. Water also
flows through the deluge valve alarm outlet to the
alarm devices.

After system shutdown, resetting the Model DDX De

luge Valve is quite simple. Doing so only requires
pushing in and turning the reset knob at the rear of the
valve (see Fig.1). The external reset feature of the
Model DDX Deluge Valve provides a means for sim
ple, economical system testing, which is one essential
facet of a good maintenance program.

The external reset feature does not, however, elimi
nate another important facet of good maintenance,

namely, periodic cleaning and inspection of the inter
nal valve parts. In the event that water builds up inside
the valve due to condensate from the air supply sys
tem 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 sec
tion titled “Draining Excess/Condensate Water From
System” in this bulletin for the detailed procedure.

The Model B Manual Emergency Station (see Fig. 3)

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, as shown in Fig.
3, 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

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506) is also available and can be provided as an op­tion.

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Whenever ambient temperature conditions are high,

the water temperature in the Model DDX Deluge

Valve’s pushrod chamber could possibly increase,

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thereby increasing the pressure in the chamber to val
ues exceeding the rated pressure of the system. In an
indoor installation where standard room 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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6.