Victaulic FireLock NXT 768N User manual

WARNING
• Read and understand all instructions before attempting to install, remove, adjust, or perform maintenance on any Victaulic piping products.
• Depressurize and drain piping systems before attempting to install, remove, adjust, or perform maintenance on any Victaulic piping
products.
• Wear safety glasses, hardhat, and foot protection.
• Save this installation, maintenance, and testing manual for future reference.
Failure to follow instructions and warnings could cause system failure, resulting in death or serious personal injury and property damage.
I-768N/769N.RBKITREBUILD KIT INSTRUCTIONS
Rebuild Kit Instructions for Series 768N FireLock NXT™Dry Valves,
Series 769N FireLock NXT™Deluge Valves, and
Series 769N FireLock NXT™Actuated Valves with Preaction Trim
I-768N/769N.RBKIT
REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
TABLE OF CONTENTS
Hazard Identification ......................................1
Overview of Replacement Parts ..............................2
Removing the System from Service ...........................3
Instructions for Replacing Internal Valve Components .............4
Maintenance of Air, Priming, and Alarm Manifold
Assemblies and Actuators ...............................10
Replacing the Cartridge in the Air and Priming
Manifold Assemblies ...................................11
Replacing the O-Rings in the Alarm and Priming
Manifold Assemblies ...................................11
Replacing the O-Ring and Filter in the Actuator ...............11
Placing the System Back in Service ..........................11
HAZARD IDENTIFICATION
Definitions for identifying the various hazard levels are
provided below. When you see this symbol, be alert to the
possibility of personal injury. Carefully read and fully
understand the message that follows.
WARNING
• The use of the word “WARNING” identifies the presence of
hazards or unsafe practices that could result in death or serious
personal injury and property damage if instructions are not
followed.
CAUTION
• The use of the word “CAUTION” identifies possible hazards or
unsafe practices that could result in personal injury and product
or property damage if instructions are not followed.
NOTICE
• The use of the word “NOTICE” identifies special instructions
that are important but not related to hazards.
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I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
OVERVIEW OF REPLACEMENT PARTS
The following drawing identifies components with replaceable parts for a typical Series 768N FireLock NXT™Dry Valve. NOTE: The trim for Series
769N FireLock NXT™ Deluge Valves and Actuated Valves with Preaction Trim will vary from what is shown below; however, the alarm manifold and
priming manifold assemblies and internal valve components are consistent throughout all valve trim configurations. Refer to the instructions on the
following pages for removing the system from service to replace these components.
Air Manifold
Actuator
Priming
Manifold
Assembly
Alarm
Manifold
Assembly
Valve Body
Orange shaded areas have internal components that are replaceable.
Pressure gauges, identied above, are replaceable items.
Water Pressure Gauge
(0 – 300 psi/0 – 2068 kPa/
0 – 20.7 Bar)
Air/Water Pressure Gauge
(0 – 80 psi/0 – 550 kPa/
0 – 5.5 Bar,
80 – 250 psi/550 – 1724 kPa/
5.5 – 17.2 Bar Retard)
with Air Pressure Label
Water Pressure Gauge
(0 – 300 psi/0 – 2068 kPa/
0 – 20.7 Bar)
with QR Code Label
WARNING
• Depressurize and drain the piping system before attempting to perform any maintenance on the valve.
• The building owner or their representative is responsible for maintaining the fire protection system in proper
operating condition.
• To ensure proper system operation, valves shall be inspected in accordance with current NFPA-25
requirements or in accordance with the requirements of the local authority having jurisdiction (whichever
is more stringent). Always refer to the instructions in this manual for additional inspection and testing
requirements.
• The frequency of inspections shall be increased in the presence of contaminated water supplies, corrosive/
scaling water supplies, and corrosive atmospheres.
• Any activities that require taking the valve out of service may eliminate the fire protection provided. A fire
patrol is strongly recommended for the affected areas.
• Before servicing or testing the system, notify the authority having jurisdiction.
Failure to follow these instructions could cause system failure, resulting in death or serious personal injury and
property damage.
I-768N/769N.RBKIT_2 REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
REMOVING THE SYSTEM FROM SERVICE
1. Notify the authority having jurisdiction, remote station alarm
monitors, and those in the affected area that the system is being
taken out of service.
2. Open the water supply main drain valve fully to flush the water
supply of any contaminants.
3. Close the water supply main drain valve.
4. Close the water supply main control valve to take the system out of
service.
5. Open the water supply main drain valve.
6. Confirm that water is not flowing from the water supply main drain
valve.
7. Close the charge line ball valve.
8. Open the system main drain valve to drain any water that has
accumulated and to release system air pressure.
NOTE: If the system has operated, open the remote system test valve
(inspector’s test connection) and any auxiliary drain valves.
9. Isolate any applicable air supply.
10. PUSH DOWN ON THE AUTO DRAIN SCREW TO REMOVE
PRESSURE IN THE CHARGE LINE. VERIFY THAT THERE IS NO
PRESSURE ON THE GAUGES.
Water
Supply
Main
Control
Valve
(Step 4)
System Main
Drain Valve
(Step 8)
Water
Supply Main
Drain Valve
(Steps 2, 3, & 5)
Charge
Line Ball
Valve
(Step 7)
Auto Drain
Screw
(Step 10)
I-768N/769N.RBKIT_3REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
INSTRUCTIONS FOR REPLACING INTERNAL VALVE COMPONENTS
12
11
7
13
13
9
6
1
3
2
4
58
12
11
10
Item Description
1Clapper Seal
2Seal Ring
3Seal Washer*
4Clapper Shaft
5Latch Shaft
6Clapper Spring
7Latch Spring
8Diaphragm
Item Description
9Cover Plate Gasket
10 Seal Assembly Bolt/Bolt Seal
11 Clapper Shaft Bushing O-Ring
12 Latch Shaft Bushing O-Ring
13 Spring Insertion Tool
* Item 3 (Seal Washer) is not used in 1½-inch/48.3-mm and 2-inch/60.3-mm valve sizes.
The 1½-inch/48.3-mm and 2-inch/60.3-mm valve sizes contain washers under the heads of the
cover plate bolts.
I-768N/769N.RBKIT_4 REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
WARNING
• Verify that the valve is depressurized and drained completely
before the cover plate bolts are removed.
Failure to follow this instruction could result in death or serious
personal injury and property damage.
1. After all pressure is released from the system, loosen the cover
plate bolts slowly. NOTE: DO NOT remove any cover plate bolts
until all cover plate bolts are loosened.
1a. Remove all cover plate bolts, along with the cover plate and
cover plate gasket. Discard the cover plate gasket. NOTE: The
1 ½-inch/48.3-mm and 2-inch/60.3-mm valve sizes contain
washers under the heads of the cover plate bolts. Keep these
washers for re-installation.
Latch
2. Push the latch back (toward the diaphragm).
3. Remove the clapper shaft bushings from the valve body. Remove
and discard the clapper shaft bushing o-rings. Keep the clapper
shaft bushings for re-installation.
4. Remove the clapper shaft. NOTE: As the clapper shaft is being
removed, the clapper spring will drop out of position. Discard the
clapper shaft and clapper spring.
5. Remove the clapper assembly from the valve body seat ring. Clean
the valve body seat ring.
6. Remove the latch shaft bushings from the valve body. Remove
and discard the latch shaft bushing o-rings. Keep the latch shaft
bushings for re-installation.
WARNING
• DO NOT allow the latch to drop onto the valve body seat ring.
Failure to follow this instruction will damage the valve body seat
ring and cause improper valve operation, resulting in death or
serious personal injury and property damage.
7. Remove the latch shaft. NOTE: As the latch shaft is being
removed, the latch and latch spring will drop out of position.
BE PREPARED TO SUPPORT THE LATCH AND LATCH SPRING
DURING REMOVAL OF THE LATCH SHAFT. DO NOT ALLOW
THE LATCH TO DROP ONTO THE VALVE BODY SEAT RING.
Discard the latch shaft and latch spring. Keep the latch for
re-installation.
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I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
This side shall
face toward the
diaphragm
This side shall
face toward the
opening of the
valve
8. Insert the new latch shaft (supplied with the kit) through the valve
body and into the first arm of the latch. VERIFY THAT THE SIDE
OF THE LATCH WITH THE RECESS IS FACING TOWARD THE
OPENING OF THE VALVE. THE FLAT SIDE OF THE LATCH
SHALL FACE TOWARD THE DIAPHRAGM, AS SHOWN ABOVE.
9. Place a spring insertion tool (supplied with the kit) onto each arm
of the new latch spring (supplied with the kit). Use the spring
insertion tool to close the latch spring arms together slightly, then
install the latch spring onto the latch shaft, as shown above.
9a. Continue to pass the latch shaft through the other arm of the latch
and into the valve body.
9b. REMOVE THE SPRING INSERTION TOOL FROM EACH ARM OF
THE LATCH SPRING.
10. Place a new latch shaft bushing o-ring (supplied with the kit) onto
each latch shaft bushing.
10a. Apply thread sealant to each latch shaft bushing. Install the latch
shaft bushings into the valve body until hand-tight.
10b. Tighten the latch shaft bushings until metal-to-metal contact
occurs with the valve body. DO NOT exceed 10 ft-lbs/14 N•m of
torque on the latch shaft bushings.
11. Place the clapper assembly onto the valve body seat ring. Ensure
that the holes in the clapper arms align with the holes in the valve
body.
12. Insert the new clapper shaft (supplied with the kit) halfway into the
valve body.
12a. Install the new clapper spring (supplied with the kit) onto the
clapper shaft. Ensure that the loop of the clapper spring is facing
the clapper, as shown above.
12b. Finish inserting the clapper shaft through the clapper arm and
valve body.
I-768N/769N.RBKIT_6 REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
13. Place a new clapper shaft bushing o-ring (supplied with the kit)
onto each clapper shaft bushing.
13a. Apply thread sealant to each clapper shaft bushing. Install the
clapper shaft bushings into the valve body until hand-tight.
13b. Tighten the clapper shaft bushings until metal-to-metal contact
occurs with the valve body. DO NOT exceed 10 ft-lbs/14 N•m of
torque on the clapper shaft bushings.
13c. Check the clapper for freedom of movement.
14. Rotate the clapper out of the valve body. Remove the seal
assembly bolt/bolt seal from the clapper seal, as shown above.
Discard the seal assembly bolt/bolt seal.
15. Remove the seal-retaining ring. Save the seal-retaining ring for
re-installation.
16. Pry the edge of the seal washer out from the inside of the clapper
seal, as shown above. Remove and discard the seal washer.
17. Carefully pry the old clapper seal, along with the seal ring, out of
the clapper. Discard the clapper seal and seal ring.
18. Remove any debris from the clapper. Inspect the clapper for
damage that may affect the sealing capabilities of the new clapper
seal. Contact Victaulic if the clapper requires replacement.
19. Install the new clapper seal (supplied with the kit) into the
clapper carefully. Ensure that the seal ring snaps into the clapper
completely.
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I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
20. Place the seal-retaining ring onto the seal washer of the clapper
seal. Install the new seal assembly bolt/bolt seal (supplied with the
kit) through the seal-retaining ring and clapper.
21. Tighten the seal assembly bolt/bolt seal to the torque value listed
in the table below to ensure a proper seal.
REQUIRED SEAL ASSEMBLY BOLT/BOLT SEAL TORQUES
Nominal Size
inches or mm
Required Torque
inch-lbs/N•m
1 ½ 40
5
240
5
2 ½ 90
10
76.1 mm 90
10
390
10
4110
12
165.1 mm 160
18
6160
18
8160
18
22. Align the holes of the new cover plate gasket (supplied with the kit)
with the holes in the cover plate.
22a. Insert one cover plate bolt through the cover plate and cover plate
gasket to ease alignment. NOTE: For 1½-inch/48.3-mm and
2-inch/60.3-mm valve sizes, a washer shall be re-installed under
the head of each cover plate bolt.
CAUTION
• DO NOT over-tighten the cover plate bolts.
Failure to follow this instruction could cause damage to the cover
plate gasket, resulting in valve leakage.
23. Align the cover plate/cover plate gasket to the valve. Ensure that
the clapper spring’s arms are rotated to their installed position.
Tighten all cover plate bolts into the cover plate/valve body.
23a. Torque all cover plate bolts in an even, crossing pattern. Refer
to the “Required Cover Plate Bolt Torques” table below for the
required torque values. DO NOT over-tighten the cover plate bolts.
REQUIRED COVER PLATE BOLT TORQUES
Nominal Size
inches or mm
Required Torque
ft-lbs/N•m
1 ½ 30
41
230
41
2 ½ 60
81
76.1 mm 60
81
360
81
4100
136
165.1 mm 115
156
6115
156
8100
136
I-768N/769N.RBKIT_8 REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
24. Break the unions that connect the trim to the diaphragm cover.
Refer to the applicable trim drawing for details.
25. Remove the cap screws from the diaphragm cover, and pull the
diaphragm cover/trim off the valve.
26. Remove the diaphragm from the valve body. Discard the
diaphragm.
27. Clean the back of the valve body to remove any debris that may
interfere with proper diaphragm seating.
27a. Clean the inside of the diaphragm cover.
CAUTION
• Use caution when installing a new diaphragm into the valve
body.
Failure to follow this instruction could cause damage to the
diaphragm, resulting in improper valve operation and valve leakage.
28. Align the holes in the new diaphragm (supplied with the kit) with
the holes in the valve body. Use caution to prevent damage to the
diaphragm during installation.
29. Align the holes of the diaphragm cover with the holes in the
diaphragm/valve body. Tighten all cap screws into the diaphragm
cover/valve body in an even, crossing pattern to a torque of
10 ft-lbs/14 N•m. Repeat this tightening sequence to verify that all
cap screws have been torqued to 10 ft-lbs/14 N•m.
30. Re-attach the trim at the unions that were loosened in step 24.
Refer to the applicable trim drawing for details. VERIFY THAT
ALL UNIONS THAT WERE LOOSENED TO PERMIT ACCESS TO
THE DIAPHRAGM COVER HAVE BEEN RE-TIGHTENED BEFORE
ATTEMPTING TO PLACE THE SYSTEM BACK IN SERVICE.
I-768N/769N.RBKIT_9REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
MAINTENANCE OF AIR, PRIMING, AND ALARM MANIFOLD ASSEMBLIES AND ACTUATORS
Face of cartridge for air manifold assembly is
stamped “AM” for identication purposes.
Replacement
Cartridge for Air
Manifold
Assembly
Air Manifold Assembly
DO NOT
apply any thread
sealant during
reassembly
NOTE: The o-ring indicated is the same for the alarm
manifold assembly and priming manifold assembly.
Refer to replacement instructions on the following page.
O-Ring
Alarm Manifold Assembly
Priming Manifold Assembly
NOTE: The o-ring indicated is the same for
the alarm manifold assembly and priming
manifold assembly.
O-Ring
Face of cartridge for priming
manifold assembly is stamped “PM”
for identication purposes.
Replacement
Cartridge for
Priming Manifold
Assembly
DO NOT
apply any thread
sealant during
reassembly
Actuator
O-Ring
Filter
NOTE: A Series 776 Low-Pressure Actuator is shown.
However, the lter is accessible in the same location for
Series 767 and 798 Actuators
DO NOT
apply any thread
sealant during
reassembly
I-768N/769N.RBKIT_10 REV_A

I-768N/769N.RBKIT / Series 768N and Series 769N FireLock NXT™Valves / Rebuild Kit Instructions
Replacing the Cartridge in the Air and Priming Manifold Assemblies
NOTE: Some Series 769N FireLock NXT™ Deluge Valve and Actuated
Valve with Preaction trim configurations do not contain air manifolds;
however, all trim configurations contain a priming manifold.
1. Remove the existing cartridge from the air manifold and priming
manifold assemblies, shown above.
2. Install the new corresponding cartridge, supplied with the kit,
into the priming manifold and air manifold assemblies. DO NOT
APPLY ANY THREAD SEALANT TO THE CARTRIDGES DURING
REASSEMBLY. NOTE: The face of the air manifold cartridge is
stamped “AM” and the face of the priming manifold cartridge is
stamped “PM.” These cartridges are designed so that they cannot
be interchanged.
Replacing the O-Rings in the Alarm and Priming Manifold Assemblies
1. Break the union above the priming manifold assembly and the
union of the alarm manifold assembly to gain access to the o-rings.
Discard the o-rings.
2. Use only new, Victaulic-supplied o-rings (supplied with the kit),
install the new o-rings onto the alarm and priming manifold
assemblies.
3. Carefully reconnect the unions to the alarm and priming manifold
assemblies. DO NOT APPLY ANY THREAD SEALANT TO THE
UNIONS DURING REASSEMBLY. Use caution to prevent damage
to the o-rings in the alarm and priming manifold assemblies.
Replacing the O-Ring and Filter in the Actuator
NOTE: The following o-ring and filter replacement section may not apply
to some Series 769N FireLock NXT™ Deluge Valve and Actuated Valve
with Preaction trim configurations.
NOTE: The Series 776 Low-Pressure Actuator is shown above.
1. Remove the actuator from the trim. Refer to the applicable trim
drawing for details.
2. Remove the filter adapter from the actuator. Discard the o-ring and
filter.
CAUTION
• DO NOT re-use filters. After removal, the old filter shall be
replaced with a new, Victaulic-supplied filter.
Failure to follow this instruction could cause improper valve
operation, resulting in property damage.
3. Use only new, Victaulic-supplied o-rings and filters. Install the new
o-ring and filter onto the filter adapter, as shown above.
4. Carefully re-install the filter adapter into the actuator. Use caution
to prevent damage to the o-ring. DO NOT APPLY ANY THREAD
SEALANT TO THE FILTER ADAPTER DURING REASSEMBLY.
5. Re-install the actuator into the trim. Refer to the applicable trim
drawing for details.
PLACING THE SYSTEM BACK IN SERVICE
After all maintenance procedures have been completed, place the
system back in service by following the “Resetting the System” section
in the applicable installation, maintenance, and testing manual.
Inspect all trim components to confirm that there are no leaks. Any
leaks shall be corrected immediately by depressurizing the system and
tightening any affected components.
I-768N/769N.RBKIT_11REV_A

I-768N/769N.RBKITREBUILD KIT INSTRUCTIONS
Rebuild Kit Instructions for Series 768N FireLock NXT™Dry Valves,
Series 769N FireLock NXT™Deluge Valves, and
Series 769N FireLock NXT™Actuated Valves with Preaction Trim
For complete contact information, visit victaulic.com
I-768N/769N.RBKIT 8964 REV A UPDATED 11/2016 Z000768NRB
VICTAULIC AND FIRELOCK NXT ARE REGISTERED TRADEMARKS OR TRADEMARKS OF VICTAULIC COMPANY AND/OR ITS AFFILIATED ENTITIES
IN THE UNITED STATES AND/OR OTHER COUNTRIES. © 2016 VICTAULIC COMPANY. ALL RIGHTS RESERVED.