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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

    Watts Water Technologies 1 in Pressure Vacuum Breaker Vent Float Kit

    Watts Water Technologies
    $ 18.00 - $ 18.00
    $ 18.00
    $ 18.00 - $ 18.00
    $ 18.00

    This 1 IN 800M4 vent repair kit provides all the parts necessary to repair the vent float of the applicable pressure vacuum breaker. This kit inclu...

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    $ 18.00 - $ 18.00
    $ 18.00
    $ 18.00 - $ 18.00
    $ 18.00
    Sold out

  • Febco - 905211 - Bonnet Repair Kit for 765 Pressure Vacuum Breakers and Backflow Preventers, 1/2 Inch and 3/4 Inch

    Febco
    $ 54.63 - $ 54.63
    $ 54.63
    $ 54.63 - $ 54.63
    $ 54.63

    This Febco 905211 Bonnet Repair Kit is designed for 765 Pressure Vacuum Breakers and Backflow Preventers, with sizes of 1/2” and 3/4”. This kit con...

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    $ 54.63 - $ 54.63
    $ 54.63
    $ 54.63 - $ 54.63
    $ 54.63

  • Watts RK 800M4-CK 1" Repair Kit 0887704

    Watts Water Technologies
    $ 34.29 - $ 34.29
    $ 34.29
    $ 34.29 - $ 34.29
    $ 34.29

    Check Valve Repair Kit for 1" 800M4-QT / 800M4-FR Pressure Vacuum Breaker This kit contains the following: Check Spring Check Disk Holder Check Di...

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    $ 34.29 - $ 34.29
    $ 34.29
    $ 34.29 - $ 34.29
    $ 34.29

  • Watts - 0887709 - 1/2"& 3/4" Float & Vent KIT, White Repair PVB

    Watts Water Technologies
    $ 14.57 - $ 14.57
    $ 14.57
    $ 14.57 - $ 14.57
    $ 14.57

    Repair kit contains: float vent, disc assembly, seal and spring, and bonnet o-ring To repair Watts 800M4-1/2 and 3/4 vacuum breaker float vent

    $ 14.57 - $ 14.57
    $ 14.57
    $ 14.57 - $ 14.57
    $ 14.57

  • Watts RK 800M4-B 1 1 IN Pressure Vacuum Breaker Bonnet Assembly Kit 0887701

    Watts Water Technologies
    $ 0.00 - $ 0.00
    $ 0.00
    $ 47.81
    $ 47.81 - $ 47.81
    $ 47.81

    This 1 IN 800M4 bonnet assembly repair kit provides all the parts necessary to replace the bonnet of the applicable pressure vacuum breaker. This ...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 47.81
    $ 47.81 - $ 47.81
    $ 47.81

  • Febco - 905212 - Bonnet and Poppet Assembly Kit for 1 inch and 1-1/4 inch Febco 765 Valves

    Febco
    $ 61.71 - $ 61.71
    $ 61.71
    $ 61.71 - $ 61.71
    $ 61.71

    Febco Bonnet and Poppet Assembly Kit 905212 is designed for 1 inch and 1-1/4 inch Febco 765 Valves. It provides long-lasting protection for pressur...

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    $ 61.71 - $ 61.71
    $ 61.71
    $ 61.71 - $ 61.71
    $ 61.71

  • Watts LFFPTC-F 1/8" - 1/8 In Lead Free Full Port Test Cock 781074LL

    Watts Water Technologies
    $ 0.00 - $ 0.00
    $ 0.00
    $ 23.60
    $ 23.60 - $ 23.60
    $ 23.60

    1/8 In Lead Free Full Port Test Cock 781074LL   This 1/8 IN lead free full port test cock is used for testing 1/2 to 1 inch lead free backflow pre...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 23.60
    $ 23.60 - $ 23.60
    $ 23.60

  • Watts LFFPTC-F 1/4" - 1/4 In Lead Free Full Port Test Cock 781075LL

    Watts Water Technologies
    $ 0.00 - $ 0.00
    $ 0.00
    $ 23.60
    $ 23.60 - $ 23.60
    $ 23.60

    This 1/4 IN lead free full port test cock is used for testing 1 1/4 to 2 inch lead free backflow preventer, as an isolation valve for gauges or as...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 23.60
    $ 23.60 - $ 23.60
    $ 23.60

  • Febco Poppet Assembly Kit for 1/2", 3/4" 765 Pressure Vacuum Breaker

    Febco
    $ 26.08 - $ 26.08
    $ 26.08
    $ 26.08
    $ 26.08 - $ 26.08
    $ 26.08

    Febco: 1/2" - 3/4" - Poppet Assembly for a 765 Pressure Vacuum Breaker

    $ 26.08 - $ 26.08
    $ 26.08
    $ 26.08
    $ 26.08 - $ 26.08
    $ 26.08
  • Sold out

    Zurn Wilkins RK1-720A 1/2" - 2" Pressure Vacuum Breaker Repair Kit

    Zurn Wilkins
    $ 81.99 - $ 81.99
    $ 81.99
    $ 81.99 - $ 81.99
    $ 81.99

    Complete repair kit for the 720A Pressure Vacuum Breaker. Kits fits the 1/2" - 2" models of the Wilkins 720A Includes poppet assembly, spider asse...

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    $ 81.99 - $ 81.99
    $ 81.99
    $ 81.99 - $ 81.99
    $ 81.99
    Sold out
  • Sold out

    Zurn Wilkins 721-20 Bonnet for 720A

    Zurn Wilkins
    $ 0.00 - $ 0.00
    $ 0.00
    $ 37.18
    $ 37.18 - $ 37.18
    $ 37.18

    Dimensions: 2" x 2" x 0.3" Weight: 1.6 oz

    $ 0.00 - $ 0.00
    $ 0.00
    $ 37.18
    $ 37.18 - $ 37.18
    $ 37.18
    Sold out

  • Watts RK 009M2-CK2 1 1 IN Reduced Pressure Zone Assembly Backflow Repair Kit, Second Check Kit, for 009M2 0887790

    Watts Water Technologies
    $ 0.00 - $ 0.00
    $ 0.00
    $ 73.60
    $ 73.60 - $ 73.60
    $ 73.60

    This 1 IN 009M2 second check repair kit provides all the parts necessary to replace the major internal components of the applicable reduced pressu...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 73.60
    $ 73.60 - $ 73.60
    $ 73.60

  • Watts - 0887789 - 1st Check Kit for 1" RPZ

    Watts Water Technologies
    $ 80.75 - $ 80.75
    $ 80.75
    $ 80.75 - $ 80.75
    $ 80.75

     1ST CHECK ASSEMBLY REPAIR KIT

    $ 80.75 - $ 80.75
    $ 80.75
    $ 80.75 - $ 80.75
    $ 80.75
  • Sold out

    Watts - 0888521 - 2nd Check Repair Kit for 3/4 Inch Reduced Pressure Zone Assembly Series 009M3

    Watts Water Technologies
    $ 0.00 - $ 0.00
    $ 0.00
    $ 36.73
    $ 36.73 - $ 36.73
    $ 36.73

    This WATTS 0888521 Second Check Repair Kit for 3/4 Inch Reduced Pressure Zone Assembly Series 009M3 is a direct replacement manufactured by Watts. ...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 36.73
    $ 36.73 - $ 36.73
    $ 36.73
    Sold out

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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The difference between a Pressure Vacuum Breaker and a Reduced Pressure Zone

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