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Back Flows

Protect your potable water—and comply with code—by selecting the right back-flow prevention devices for your irrigation system. Our Back Flow Preventers & Parts collection offers trusted assemblies and accessories built for homeowners, DIYers, and pros alike.

Whether you’re installing a new lawn sprinkler system or upgrading an existing irrigation setup, a proper back-flow preventer is a critical safeguard. These devices stop the reversal of water flow—known as back-siphonage or back-pressure—which can draw fertilizers, soil bacteria, and other contaminants into your drinking water supply.

Shop by type

  • PVB (Pressure Vacuum Breaker): common for lawn irrigation; must be installed above grade and typically 12" above highest downstream outlet.
  • RPZ / RP (Reduced Pressure Zone): highest protection for high-hazard or fertilizer/chem injection; requires drain/relief discharge area.
  • DC / DCVA (Double Check Valve Assembly): used where allowed for low-hazard irrigation without chemicals.
  • AVB (Atmospheric Vacuum Breaker): zone-level protection; not for continuous pressure (typically one per zone where permitted).

What you'll find

  • Sizes: 3/4", 1", 1-1/2", 2" (select larger commercial sizes available)
  • Options & parts: union ball valves, test cocks, lead-free models, repair kits (bonnets, checks, relief assemblies), freeze covers
  • Brands: Febco, Watts Water, Apollo, Zurn (Wilkins)

Why choose Big Frog Supply? We focus on irrigation, plumbing and landscape lighting supplies—so you’re not just buying a part, you’re tapping into expert-curated gear, reliable inventory, and a partner who speaks “sprinkler system” language.

  • Sold out

    Apollo - 4A204A4F - 3/4 in. Bronze FIP Reduced Pressure Backflow Preventer with Union Shut-Off Valves

    Apollo
    $ 323.85 - $ 323.85
    $ 323.85
    $ 323.85 - $ 323.85
    $ 323.85

    This item with threaded connections is designed to prevent the back flow of polluted water from entering into the potable water supply due to back ...

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    $ 323.85 - $ 323.85
    $ 323.85
    $ 323.85 - $ 323.85
    $ 323.85
    Sold out
  • Sold out

    Apollo - Backflow Preventer, Reduced Pressure, Bronze with Ball Valves and SAE Test Cocks

    Apollo
    $ 274.00 - $ 327.14
    $ 274.00 - $ 327.14
    $ 274.00 - $ 327.14
    $ 274.00

    This vacuum breaker prevents contamination of the potable water due to back siphon-age. A integrated freeze protection relief valve serves to reduc...

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    $ 274.00 - $ 327.14
    $ 274.00 - $ 327.14
    $ 274.00 - $ 327.14
    $ 274.00
    Sold out

  • Febco - 860-QT RP 100 - 1" 860 Reduced Pressure Zone Assembly

    Febco
    $ 206.18 - $ 206.18
    $ 206.18
    $ 593.68
    $ 593.68 - $ 593.68
    $ 593.68

    Spec Sheet Freeze Prevention Maintenance   The FEBCO Series 860 Reduced Pressure Zone Assemblies are for use in health-hazard applications. The s...

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    $ 206.18 - $ 206.18
    $ 206.18
    $ 593.68
    $ 593.68 - $ 593.68
    $ 593.68

  • Watts - LF25AUB-Z3 - Water Pressure Reducing Valve 1 Inch Pipe Size 0009309

    Watts Water Technologies
    $ 429.97 - $ 429.97
    $ 429.97
    $ 429.97 - $ 429.97
    $ 429.97

    Spec Sheet Pressure reducing valves are usually installed in front of piping to help maintain pressure throughout your home. Watts Water Pressure R...

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    $ 429.97 - $ 429.97
    $ 429.97
    $ 429.97 - $ 429.97
    $ 429.97
  • Sold out

    Watts - 1-LF009M2-QT - Backflow System Low Pressure, 1" FIP 0391004

    Watts Water Technologies
    $ 713.36 - $ 713.36
    $ 713.36
    $ 713.36 - $ 713.36
    $ 713.36

    This 1 inch Lead Free reduced pressure zone assembly is designed to prevent the backflow of polluted water from entering into the potable water su...

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    $ 713.36 - $ 713.36
    $ 713.36
    $ 713.36 - $ 713.36
    $ 713.36
    Sold out
  • Sold out

    Watts - 2-LF009M2-QT - Backflow System Low Pressure, 2" FIP

    Watts Water Technologies
    $ 1,111.71 - $ 1,111.71
    $ 1,111.71
    $ 1,111.71 - $ 1,111.71
    $ 1,111.71

    This 2 inch reduced pressure zone assembly is designed to prevent the flow of polluted water from entering into the potable water supply due to...

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    $ 1,111.71 - $ 1,111.71
    $ 1,111.71
    $ 1,111.71 - $ 1,111.71
    $ 1,111.71
    Sold out

  • Watts - 11/2-LF009M2-QT - 1.5-LF009M2-QT Backflow System Low Pressure, 1 1/2" FIP

    Watts Water Technologies
    $ 1,171.76 - $ 1,171.76
    $ 1,171.76
    $ 1,171.76 - $ 1,171.76
    $ 1,171.76

      This 1 1/2 inch reduced pressure zone assembly is designed to prevent the flow of polluted water from entering into the potable water supply...

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    $ 1,171.76 - $ 1,171.76
    $ 1,171.76
    $ 1,171.76 - $ 1,171.76
    $ 1,171.76

  • Watts 0125572 3/4" LF25AUB-Z3 Pressure Reducing Valve (Press) Lead Free

    Watts Water Technologies
    $ 223.36 - $ 223.36
    $ 223.36
    $ 223.36 - $ 223.36
    $ 223.36

    Specs Installation   Maximum Working Pressure: 300psi (21 bar)Adjustable Reduced Pressure Range: 25 to 75psi (172 to 517 kPa)Standard Pressure ...

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    $ 223.36 - $ 223.36
    $ 223.36
    $ 223.36 - $ 223.36
    $ 223.36
  • Sold out

    Watts - 34-LF009M3-QT - Backflow System Low Pressure, 3/4" FIP

    Watts Water Technologies
    $ 483.32 - $ 483.32
    $ 483.32
    $ 483.32 - $ 483.32
    $ 483.32

    This 3/4 inch reduced pressure zone assembly is designed to prevent the flow of polluted water from entering into the potable water supply due to...

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    $ 483.32 - $ 483.32
    $ 483.32
    $ 483.32 - $ 483.32
    $ 483.32
    Sold out

  • Watts - 1-LF007M1-QT - 1 inch LF007M1-QT 1 Double Check Valve 0063232

    Watts Water Technologies
    $ 455.99 - $ 455.99
    $ 455.99
    $ 455.99 - $ 455.99
    $ 455.99

    This 1 inch lead free double check valve backflow preventer assembly is designed to prevent the backflow of polluted water from entering into the p...

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    $ 455.99 - $ 455.99
    $ 455.99
    $ 455.99 - $ 455.99
    $ 455.99

  • Febco 1" RPZ Principal Assembly (Top Access) 1" 860-QT-FS RP F1313

    Febco
    $ 525.99 - $ 525.99
    $ 525.99
    $ 525.99
    $ 525.99 - $ 525.99
    $ 525.99

    This 1 inch reduced pressure zone backflow preventer assembly prevents the reverse flow of high hazard (toxic) fluids found in the water from ente...

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    $ 525.99 - $ 525.99
    $ 525.99
    $ 525.99
    $ 525.99 - $ 525.99
    $ 525.99

  • Febco -F1314 - 1 1/4 IN Bronze Reduced Pressure Zone Backflow Preventer Assembly with Quarter Turn Shutoff, Small Diameter & Flood Sensor 860-QT-RP-FS

    Febco
    $ 0.00 - $ 0.00
    $ 0.00
    $ 885.90
    $ 885.90 - $ 885.90
    $ 885.90

    This 1 1/4 inch reduced pressure zone backflow preventer assembly prevents the reverse flow of high hazard (toxic) fluids found in the water from e...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 885.90
    $ 885.90 - $ 885.90
    $ 885.90

  • Febco - 860-QT-FS 2 - 2 IN Bronze Reduced Pressure Zone Backflow Preventer Assembly, Quarter Turn Shutoff, Small Diameter, Backflow Flood Sensor F1316

    Febco
    $ 1.00 - $ 1.00
    $ 1.00
    $ 1,391.24
    $ 1,391.24 - $ 1,391.24
    $ 1,391.24

    2 IN Bronze Reduced Pressure Zone Backflow Preventer Assembly, Quarter Turn Shutoff, Small Diameter, Backflow Flood Sensor  This item does not comp...

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    $ 1.00 - $ 1.00
    $ 1.00
    $ 1,391.24
    $ 1,391.24 - $ 1,391.24
    $ 1,391.24

  • Febco - 860U-QT-FS 3/4 - 3/4 IN Bronze Reduced Pressure Zone Backflow Preventer Assembly, Quarter Turn Shutoff, Union Ball Valves, Small Diameter, Backflow Flood Sensor

    Febco
    $ 0.00 - $ 0.00
    $ 0.00
    $ 464.97
    $ 464.97 - $ 464.97
    $ 464.97

    3/4 IN Bronze Reduced Pressure Zone Backflow Preventer Assembly, Quarter Turn Shutoff, Union Ball Valves, Small Diameter, Backflow Flood Sensor Thi...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 464.97
    $ 464.97 - $ 464.97
    $ 464.97

  • Zurn Wilkins 1-975XL 1" 975XL Reduced Pressure Principle Assembly

    Zurn Wilkins
    $ 777.99 - $ 777.99
    $ 777.99
    $ 777.99 - $ 777.99
    $ 777.99

    The 975XL Reduced Pressure Principle Backflow Assembly is used on non-potable water applications for high health hazard protection from both backsi...

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    $ 777.99 - $ 777.99
    $ 777.99
    $ 777.99 - $ 777.99
    $ 777.99

  • Zurn Wilkins 1-975XLS 1" 975XL Reduced Pressure Assembly w/ Bronze Wye Strainer (Discontinued)

    Zurn Wilkins
    $ 902.99 - $ 902.99
    $ 902.99
    $ 902.99 - $ 902.99
    $ 902.99

    The Zurn Wilkins 975XL Reduced Pressure Principle Backflow Preventer provides high hazard protection for non-potable water applications. The wye p...

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    $ 902.99 - $ 902.99
    $ 902.99
    $ 902.99 - $ 902.99
    $ 902.99

  • Zurn 1-975XL3 1" Reduced Pressure Principle Backflow Preventer

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 936.99
    $ 936.99 - $ 936.99
    $ 936.99

    The Zurn Wilkins 975XL3 Reduced Pressure Principle Backflow Assembly provides high hazard protection against backsiphonage and backpressure in pota...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 936.99
    $ 936.99 - $ 936.99
    $ 936.99

  • Zurn Wilkins 34-975XL 3/4" Reduced Pressure Principle Backflow Preventor

    Zurn Wilkins
    $ 732.99 - $ 732.99
    $ 732.99
    $ 732.99 - $ 732.99
    $ 732.99

    The Zurn Wilkins 975XL Reduced Pressure Principle Backflow Preventer provides high hazard protection for non-potable water applications. The wye p...

    View full details
    $ 732.99 - $ 732.99
    $ 732.99
    $ 732.99 - $ 732.99
    $ 732.99

  • Zurn Wilkins 34-975XL2 3/4" 975XL2 Reduced Pressure Principle Assembly (Lead Free)

    Zurn Wilkins
    $ 1,025.99 - $ 1,025.99
    $ 1,025.99
    $ 1,025.99 - $ 1,025.99
    $ 1,025.99

    Spec Sheet   Install Manual The Zurn Wilkins 975XL2 Reduced Pressure Principle Backflow Preventer provides high hazard protection for potable wa...

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    $ 1,025.99 - $ 1,025.99
    $ 1,025.99
    $ 1,025.99 - $ 1,025.99
    $ 1,025.99

  • Zurn 1" 375 RP Ball Vlv NPT Top Access Lead Free Red Pressure Principle Backflow Preventer

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 936.99
    $ 936.99 - $ 936.99
    $ 936.99

    The Zurn Wilkins 375XL Reduced Pressure Principle Backflow Preventer provides high hazard protection for potable water applications. The EZSwap Pr...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 936.99
    $ 936.99 - $ 936.99
    $ 936.99

  • Zurn 1-975XL2 1" Reduced Pressure Principle Backflow Preventer No Lead

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,084.99
    $ 1,084.99 - $ 1,084.99
    $ 1,084.99

    The 975XL2 Reduced Pressure Principle Assembly is used in high health hazard, potable water applications for protection from both backsiphonage and...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,084.99
    $ 1,084.99 - $ 1,084.99
    $ 1,084.99

  • Zurn Wilkins 34-375XL 3/4" 375 Reduced Pressure Principle Backflow Preventer

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 884.99
    $ 884.99 - $ 884.99
    $ 884.99

    375 Reduced Pressure Principle Backflow Assembly Spec Sheet The 375 Reduced Pressure Principle Backflow Assembly is utilized where a potential hig...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 884.99
    $ 884.99 - $ 884.99
    $ 884.99

  • Zurn 1/2" 975 Reduced Pressure Principle Backflow Preventer Lead Free

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 981.99
    $ 981.99 - $ 981.99
    $ 981.99

    The Zurn Wilkins 975XL2 Reduced Pressure Principle Backflow Preventer provides high hazard protection for potable water applications. The wye patte...

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 981.99
    $ 981.99 - $ 981.99
    $ 981.99

  • Zurn Wilkins 4-375AST 4" 375 Reduced Pressure Principle Backflow Preventer with Stainless Steel Body

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 6,401.99
    $ 6,401.99 - $ 6,401.99
    $ 6,401.99

    375 Reduced Pressure Principle Backflow Assembly Spec Sheet The 375 Reduced Pressure Principle Backflow Assembly is utilized where a potential hig...

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 6,401.99
    $ 6,401.99 - $ 6,401.99
    $ 6,401.99

Before installing, check your local water-utility or code requirements—many jurisdictions mandate annual testing or specific assembly types based on flow, hazard level or chemical injection. Choose the correct device, install it properly (above grade or per elevation specs), and test or maintain it regularly to ensure protection long-term.

Browse through the collection to find the right size, type and brand for your project—then install with confidence knowing your potable supply is locked down.

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