I-768N
/ Series 768N FireLock NXT
™
Dry Valve
/ Installation, Maintenance, and Testing Manual
TABLE OF CONTENTS
Hazard Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installer Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Important Installation Information . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Hydrostatic Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Receiving the Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Trim Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Trim Components - Exploded View Drawing. . . . . . . . . . . . . . . . . . . 7
Internal Valve Components - Section View and
Exploded View Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Air Supply Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Base- or Riser-Mounted Air Compressors . . . . . . . . . . . . . . . . . . . . 9
Shop Air or Tank-Mounted Air Compressors. . . . . . . . . . . . . . . . . . . 9
Compressor Requirements and Settings for a Series 768N FireLock
NXT Dry Valve Installed with a Series 746-LPA Dry Accelerator . . . . 9
Settings for Air Supervisory Pressure Switches and Alarm
Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
SECTION I
Initial System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
SECTION II
Resetting the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
SECTION III
Weekly External Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Monthly External Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
SECTION IV
Required Main Drain Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Required Water Flow Alarm Test . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Required Water Level and Low-Air Alarm Tests . . . . . . . . . . . . . . . 21
Required Partial Operational Trip Test . . . . . . . . . . . . . . . . . . . . . . 22
Required Full Operational Trip Test . . . . . . . . . . . . . . . . . . . . . . . . 23
SECTION V
Required Internal Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
SECTION VI
Removing and Replacing the Clapper Seal. . . . . . . . . . . . . . . . . . . 27
Removing and Replacing the Clapper Assembly. . . . . . . . . . . . . . . 28
Installing the Cover Plate Gasket and Cover Plate. . . . . . . . . . . . . . 29
Removing and Replacing the Diaphragm Assembly . . . . . . . . . . . . 30
Cleaning the Cartridge in the Air and Priming
Manifold Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Replacing the Filter in Series 776 Low-Pressure Actuators. . . . . . . 31
SECTION VII
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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
u nderstand 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.
INSTALLER SAFETY INFORMATION
WARNING
• An experienced, trained installer must install this product in
accordance with all instructions. These i nstructions contain
important information.
• Depressurize and drain the piping system before attempting to
install, remove, adjust, or maintain any Victaulic piping products.
Failure to follow these instructions can cause product failure,
resulting in death or serious personal injury and property damage.
1. Read and understand all instructions and refer to the trim
diagrams before installing, maintaining, or testing this Victaulic
Series 768N FireLock NXT Dry Valve.
For proper operation
and approval, the Series 768N FireLock NXT Dry Valve and
accessories must be installed in accordance with the specific trim
diagrams included with the shipment.
2. Use only recommended accessories.
Accessories and equipment
that are not approved for use with this dry valve may cause
improper system operation and property damage.
3. Wear safety glasses, hardhat, foot protection, and hearing
protection.
Wear hearing protection if you are exposed to long
periods of noisy jobsite operations.
4. Prevent back injury.
Valve assemblies require more than one
person (or mechanical lifting equipment) to position and install the
assembly. Always practice proper lifting techniques.
5. Keep work areas clean.
Keep the work area clean and well lit, and
allow enough space to accommodate proper installation of the
valve, trim, and accessories.
6. Avoid pinch points.
Due to the weight of the valve body, use
caution around pinch points and spring-loaded components
(i.e. clapper assembly) in order to prevent bodily injury.
IMPORTANT INSTALLATION INFORMATION
1. Confirm that adequate space is available for valve, trim, and
accessories.
Refer to page 6 for dimensional information.
2. Flush water supply piping.
Before installing the Series 768N
FireLock NXT Dry Valve, flush the water supply piping thoroughly
to remove all foreign material.
3. Protect system from freezing temperatures.
Series 768N FireLock
NXT Dry Valves and supply piping MUST NOT be located in an
area where the valve can be exposed to freezing temperatures or
mechanical damage.
4. Confirm material compatibility.
It is the system designer’s
responsibility to confirm material compatibility of the Series 768N
FireLock NXT Dry Valve, trim, and associated accessories when a
corrosive environment or contaminated water is present.
5. Supply air or nitrogen to the system.
Air or nitrogen supply to the
dry piping system must be clean, dry, and oil-free and must be
regulated, restricted, and uninterrupted. Refer to the “Air Supply
Requirements” section. Observe the system air pressure over a
24-hour period to confirm system integrity. If there is degradation
in system air pressure, find and correct all leaks.
NOTE:
NFPA
requires less than 11/2-psi/10-kPa/0.1-Bar leakage in 24 hours.
6. Supply water to the system.
Supply pressure to the charge line
by providing an uninterrupted source of water from upstream of
the main control valve. When an uninterrupted water flow alarm is
required, Victaulic recommends the use of a low-pressure alarm
I-768N_4
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