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Watts 800M4QT PVB Backflow Preventer 1 in. FPT | WA800M4QT-100

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Sales Price $195.95 Our Price $249.95 You save 22%

Watts 800M4-QT 1 in. Backflow Preventer

Series 800M4QT Anti-Siphon Pressure Vacuum Breakers prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage. It consists of bronze body construction, silicone rubber check valve disc, plastic check valve seat, stainless steel springs, a bonnet with silicone rubber O-ring seal, a lightweight plastic disc float, tee handle or lever handle shutoffs, and test cocks for winterization draining. Series 800M4QT is ideal in health hazard continuous pressure applications such as irrigation systems and industrial process water systems where the water enters the equipment at or below its flood rim. Maximum Pressure:150psi (10.3 bar), Minimum Pressure: 15psi (55kPa). Note: Needs to be protected from ice damage.

Features & Benefits
  • Replaceable plastic seat
  • Easy maintenance of internal parts
  • Acetal bonnet acts as “freeze plug” to prevent body damage
  • 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 11/4" 2" (32 50mm) feature lever handles
  • No special tools required for servicing
  • Bronze body for durability


  • Temperature Range: 33 F to 140 (0.5 C to 60 C)
  • Maximum Working Pressure: 150psi (10.3 bar)
  • Stainless Steel Springs
  • Celcon Bonnet
  • Silicone Rubber Vent Disc
  • Polypropylene Disc Holder Float
  • Silicone Rubber Check Valve Disc
  • Noryl Plastic Check Valve Seat
  • Bronze Body
  • Adequate drainage/freeze protection must be provided in cold weather applications.
  • 1.5psi (10 kPa) must be exerted against the float spring to seal the float and air inlet.
  • *Typical maximum flow rate (7.5 feet/sec.)
More Information
Brand Watts
Test Cocks 2 MALE
Max Working Pressure 150 PSI
Hydrostatic Test Pressure 300 PSI
Temperature Range 33F to 140F
Main Valve Body Materials Bronze
Elastomers Silicone
Springs Stainless Steel
Warranty 1 Year
Size 1 in.
Connection FPT
Lead Free Not Lead Free
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