Product Overview

Series 800M4FR
Freeze-Resistant Pressure Vacuum
Breakers
Sizes:
1
⁄2" – 2" (15 – 50mm)
Series 800M4FR is designed to prevent back-siphonage of
contaminated water under continuous pressure into the
potable water supply. Its superior design protects the valve
body and internal components during sudden freeze condi-
tions. Water inside the PVB freezes from the outside-inward.
As the ice forms and expands, causing a buildup of pressure,
the 800M4FR relieves the pressure through a unique relief valve
built into the plastic float.
Test cocks are positioned at the lowest point of the valve for
winterization draining. The 800M4FR is reusable with the relief
valve designed to automatically re-seat. It will not discharge
through the relief valve during normal operation. (The built-in
relief valve is not designed to provide freeze protection for the
entire irrigation system.)
Features
• Unique built-in relief valve relieves pressure caused by ice
formation
• Replaceable plastic seat
• Easy maintenance of internal parts
• O-ring bonnet seal for less possibility of fouling
• Silicone seat disc for durability
• Test cocks positioned for easy testing and winterization
• Compact space saving design
• Standardly equipped with tee handle quarter turn ball valve
shutoffs
1
⁄2" – 1" (15 – 25mm). The 1
1
⁄4" – 2" (32 – 50mm)
feature lever handles
• No special tools required for servicing
• Bronze body for durability
Available Models
Prefix: U – union connections (
3
⁄4" - 1" only)
Suffix: QC – Quick-Connect Adapters
For Health Hazard Applications
ES-800M4FR
Job Name
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Approval
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Engineer
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Approval
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Representative
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800M4FR
Patent #5551473
Specifications
Pressure Vacuum Breakers
A pressure anti-siphon vacuum breaker shall be installed where
indicated on the plans to prevent the back-siphonage of con-
taminated water. This assembly is not to be used where there
is a possibility that a back pressure condition may develop. The
assembly will incorporate an acetal bonnet with silicone rubber
O-ring seal and silicone rubber seat disc. The valve shall have
replaceable seats. Check assembly shall be guided over its full
stroke by ‘V’ notch guides.
The assembly shall include an internal, built-in relief valve
designed to protect the internal components and the backflow
body from freezing. The relief valve shall be repeatable, auto-
matically re-seating when the pressure within the valve is below
the set point of the freeze relief valve.
The assembly shall meet the requirements of ANSI/ASSE
Standard 1020.
The valve shall be a Watts Regulator Company Series
800M4FR.
Now Available
WattsBox Insulated Enclosures.
For more information, send for literature ES-WB.
Watts product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements,
please contact Watts Technical Service. Watts 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 Watts products previously or subsequently sold.