Specification

Pressure Vacuum Breaker assemblies shall be installed a minimum
of 12" (300mm) above the highest downstream outlet, and the
highest point in the downstream piping. The assembly shall be
rated to 150psi working pressure and water temperature from
32°F to 140°F. The assembly shall meet the specifications of the
USC FCCC & HR Manual.
Pressure Vacuum Breaker assemblies shall be FEBCO Series 765
or prior approved equal.
Approvals – Standards
• Approved by the Foundation for Cross-Connection Control and
Hydraulic Research at the University of Southern California.
Applications
PVB assemblies are used to protect against health hazard and
non-health hazard backsiphonage conditions in industrial plants,
cooling towers laboratories, laundries, swimming pools and lawn
sprinkler systems.
Typical Installation
Pressure Vacuum Breaker assemblies should be installed at least
12" (300mm) above the highest piping and outlet downstream of
the assembly to preclude backpressure. Assemblies should be
installed so they are easily accessible for maintenance, periodic
testing, and where discharge will not be objectionable. They
should be protected from freezing. If the assemblies are subject
to freezing temperatures, the freeze protection procedures
outlined in "Service Instruction Freeze Protection Model 765"
must be followed. Assemblies must not be installed where
backpressure could occur.
The discharge pressure shall be maintained above 3.0psi on
1
⁄2" - 1
1
⁄4" (15 - 32mm) sizes and 5.0psi on 1
1
⁄2"- 2" (40 - 50mm)
sizes to insure seating of the spring loaded air inlet poppet.
ES-F-765
Series 765
Pressure Vacuum Breakers
Size:
1
⁄2" - 2" (15mm - 50mm)
For Non-Health Hazard Applications
Job Name
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Approval
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Engineer
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FEBCO product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements,
please contact FEBCO Technical Service. FEBCO reserves the right to change or modify product design, construction, specifications, or materials with-
out prior notice and without incurring any obligation to make such changes and modifications on FEBCO products previously or subsequently sold.
The FEBCO Series 765 Pressure Vacuum Breakers are used to
protect against health hazard and non-health hazard backsiphonage
conditions in industrial plants, cooling towers laboratories, laundries,
swimming pools and lawn sprinkler systems.
Features
• All bronze body for durability. One check valve and an air
opening port in one assembly.
• Lightweight poppet seals air opening under minimum flow
conditions.
• Simple service procedures. All internal parts serviceable in line
from the top of the unit.
• Designed for minimum head loss.
• Engineered plastic bonnet protect valve bodies from freeze
damage.
• Optional union end ball valves for easy removal and ultimate
freeze protection.
• End Connections – NPT ANSI/ASME B1.20.1
Operation
The FEBCO 765 PVB is designed to be installed to provide
protection against backsiphonage of toxic or non-toxic liquids.
It consists of a spring loaded check valve which closes tightly when
the pressure in the assembly drops below 1psi or when zero flow
occurs, plus, an air relief valve that opens to break a siphon when
the pressure in the assembly drops to 1psi.
Specifications
Pressure Vacuum Breaker assemblies shall be in stalled to withstand
pressure for long periods and to prevent backflow of contaminated
water into the potable water system in backsiphonage conditions.
The Pressure Vacuum Breaker assembly shall consist of a single
spring loaded check valve which closes tightly when water flow
through the assembly drops to zero, and a single air relief valve
that opens to break the siphon when pressure drops to 1psi.
The assembly shall include two resilient seated shut-offs and two
resilient seated test cocks, considered integral to the assembly.
Assemblies must be factory backflow tested. The check valve
and air inlet valve must be constructed to allow in-line servicing
of the assembly. The valve body shall be constructed of bronze.
The check, poppet and bonnet assembly shall be constructed of
engineered plastic to protect the valve body from freeze damage.
765
765 U
Thermal water expansion and/or water hammer down stream of
the backflow preventer can cause pressure increases. Excessive
pressure should be eliminated to avoid possible damage to the
system and assembly.
12" (300mm) above the highest downstream
outlet and the highest point in
the downstream piping
Flow
1020 B64.1.2
It is illegal to use this product in any plumbing system providing water for
human consumption, such as drinking or dishwashing, in the United States.
Before installing standard material product, consult your local water authority,
building and plumbing codes.
WARNING
!