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.
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Zurn Wilkins 114-600XL 1-1/4" 600XL Pressure Reducing Valve
Zurn WilkinsOriginal price $ 861.99 - Original price $ 861.99Original price$ 861.99$ 861.99 - $ 861.99Current price $ 861.99The 600XL Pressure Reducing Valve handles sandy, debris-laden water systems for high-flow capacity in residential, commercial, and new construction...
View full detailsOriginal price $ 861.99 - Original price $ 861.99Original price$ 861.99$ 861.99 - $ 861.99Current price $ 861.99Sold out -
Zurn Wilkins 112-720A 1-1/2" 720A Pressure Vacuum Breaker Assembly
Zurn WilkinsOriginal price $ 795.99 - Original price $ 795.99Original price$ 795.99$ 795.99 - $ 795.99Current price $ 795.99Our Pressure Vacuum Breaker protects against back siphonage in high health hazard, non-potable residential and commercial irrigation applications. ...
View full detailsOriginal price $ 795.99 - Original price $ 795.99Original price$ 795.99$ 795.99 - $ 795.99Current price $ 795.99Sold out -
Zurn Wilkins 114-NR3XL 1 1/4 in. NR3XL Pressure Reducing Valve, Single Union FNPT Connection
Zurn WilkinsOriginal price $ 659.99 - Original price $ 659.99Original price$ 659.99$ 659.99 - $ 659.99Current price $ 659.99Our time-tested Pressure Reducing Valves are ideal for residential applications that require frequent cleaning of sediment and debris prevent build...
View full detailsOriginal price $ 659.99 - Original price $ 659.99Original price$ 659.99$ 659.99 - $ 659.99Current price $ 659.99Sold out -
Zurn Wilkins 112-NR3XLDUC 1-1/2" NR3XL Pressure Reducing Valve with Double Union FNPT Copper Sweat Connection
Zurn WilkinsOriginal price $ 1,096.99 - Original price $ 1,096.99Original price$ 1,096.99$ 1,096.99 - $ 1,096.99Current price $ 1,096.99Our time-tested Pressure Reducing Valves are ideal for residential applications that require frequent cleaning of sediment and debris prevent build...
View full detailsOriginal price $ 1,096.99 - Original price $ 1,096.99Original price$ 1,096.99$ 1,096.99 - $ 1,096.99Current price $ 1,096.99Sold out -
Zurn Wilkins 34-NR3XLDU 3/4" Lead Free Water Pressure Reducing Valve w/ Integral By-Pass Check Valve
Zurn WilkinsOriginal price $ 232.99 - Original price $ 232.99Original price$ 232.99$ 232.99 - $ 232.99Current price $ 232.99Ideal for use where lead free valves are required. Designed for installation on potable water lines to reduce high inlet pressure to a lower outle...
View full detailsOriginal price $ 232.99 - Original price $ 232.99Original price$ 232.99$ 232.99 - $ 232.99Current price $ 232.99Sold out -
Zurn Wilkins 1-70XLDU 1" Pressure Reducing Valve w/ FNPT Double Union Connections
Zurn WilkinsOriginal price $ 298.99 - Original price $ 298.99Original price$ 298.99$ 298.99 - $ 298.99Current price $ 298.99The model 70XL has been providing residential and commercial customers with ruggedness and ease of repair for over 40 years. Ideal for use where Le...
View full detailsOriginal price $ 298.99 - Original price $ 298.99Original price$ 298.99$ 298.99 - $ 298.99Current price $ 298.99Sold out -
Zurn Wilkins 112-975XL2S 1-1/2" Lead Free Wilkins 975XL2 Reduced Pressure Principle Assembly w/ Bronze "Y" Strainer
Zurn WilkinsOriginal price $ 2,260.99 - Original price $ 2,260.99Original price$ 2,260.99$ 2,260.99 - $ 2,260.99Current price $ 2,260.99The 975XL2 Reduced Pressure Principle Assembly is used in high health hazard, potable water applications for protection from both backsiphonage and...
View full detailsOriginal price $ 2,260.99 - Original price $ 2,260.99Original price$ 2,260.99$ 2,260.99 - $ 2,260.99Current price $ 2,260.99Sold out -
Zurn Wilkins 1-600XL 1" Lead Free FNPT Union x FNPT Pressure Reducing Valve
Zurn WilkinsOriginal price $ 483.99 - Original price $ 483.99Original price$ 483.99$ 483.99 - $ 483.99Current price $ 483.99Zurn Wilkins Model 34-600XL 1" Water Pressure Reducing Brass Valve with Integral By-pass Check Valve and Strainer, FNPT Union x FNPT, Lead Free ...
View full detailsOriginal price $ 483.99 - Original price $ 483.99Original price$ 483.99$ 483.99 - $ 483.99Current price $ 483.99Sold out -
Zurn Wilkins 1-NR3XL 1" NR3 Water Pressure Reducing Valve
Zurn WilkinsOriginal price $ 274.99 - Original price $ 274.99Original price$ 274.99$ 274.99 - $ 274.99Current price $ 274.99The NR3XL Pressure Reducing Valve provides reliable pressure reduction for residential applications, and is available with a variety of end connec...
View full detailsOriginal price $ 274.99 - Original price $ 274.99Original price$ 274.99$ 274.99 - $ 274.99Current price $ 274.99Sold out -
Zurn Wilkins 34-950XLT2 3/4" Wilkins 950XLT2 Double Check Valve Assembly (Lead Free)
Zurn WilkinsOriginal price $ 486.99 - Original price $ 486.99Original price$ 486.99$ 486.99 - $ 486.99Current price $ 486.99The Zurn Wilkins 950XLT2 Double Check Valve Assembly provides top access check covers. Suitable for below grade installation in standard valve box...
View full detailsOriginal price $ 486.99 - Original price $ 486.99Original price$ 486.99$ 486.99 - $ 486.99Current price $ 486.99Sold out -
Zurn Wilkins RK1-720A 1/2" - 2" Pressure Vacuum Breaker Repair Kit
Zurn WilkinsOriginal price $ 81.99 - Original price $ 81.99Original price$ 81.99$ 81.99 - $ 81.99Current price $ 81.99Complete repair kit for the 720A Pressure Vacuum Breaker. Kits fits the 1/2" - 2" models of the Wilkins 720A Includes poppet assembly, spider asse...
View full detailsOriginal price $ 81.99 - Original price $ 81.99Original price$ 81.99$ 81.99 - $ 81.99Current price $ 81.99Sold out -
Zurn Wilkins 114-720A 720A 1.25 inch PVB Backflow Preventer
Zurn WilkinsOriginal price $ 716.99 - Original price $ 716.99Original price$ 716.99$ 716.99 - $ 716.99Current price $ 716.99Designed for installation on potable water lines to protect against backsiphonage of contaminated water into the potable water supply. Assembly sh...
View full detailsOriginal price $ 716.99 - Original price $ 716.99Original price$ 716.99$ 716.99 - $ 716.99Current price $ 716.99Sold out -
Zurn Wilkins 34-600XL 600XL FNPT Union x FNPT Pressure Reducing Valve (Lead Free)
Zurn WilkinsOriginal price $ 334.99 - Original price $ 334.99Original price$ 334.99$ 334.99 - $ 334.99Current price $ 334.99Zurn Wilkins Model 34-600XL 3/4" Water Pressure Reducing Brass Valve with Integral By-pass Check Valve and Strainer, FNPT Union x FNPT, Lead Free ...
View full detailsOriginal price $ 334.99 - Original price $ 334.99Original price$ 334.99$ 334.99 - $ 334.99Current price $ 334.99Sold out -
Zurn Wilkins 721-20 Bonnet for 720A
Zurn WilkinsOriginal price $ 0.00 - Original price $ 0.00Original price $ 0.00$ 37.18$ 37.18 - $ 37.18Current price $ 37.18Dimensions: 2" x 2" x 0.3" Weight: 1.6 oz
Original price $ 0.00 - Original price $ 0.00Original price $ 0.00$ 37.18$ 37.18 - $ 37.18Current price $ 37.18Sold out
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Freeze Protecting Your Pressure Vacuum Breaker
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The difference between a Pressure Vacuum Breaker and a Reduced Pressure Zone
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