PlumbingSupply.com® logo
The Leading Online Plumbing Supplier Since 1995
Product Search:

Largest Inventory - Best Service - Lowest Prices
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Same day shipping on in-stock orders placed before 4:30pm Pacific Time M-F



Simple, straightforward and low shipping rates for these backflow preventers.


Double Check Backflow Preventers
By Watts


Help to protect yourself, your family and your customers with backflow devices from PlumbingSupply.com®. These industrial quality backflow preventers are offered in an array of configurations that will take care of your heavy duty and commercial needs, helping protect your water supply from the potential risk of contamination.

Series 007 Double Check Valve Backflow Preventer
w/ Quarter Turn Valves
example of the Watts 007-QT double check back flow preventer
Shown: 007QT
    This double check valve features:
  • Prevents the backflow of polluted water from contaminating the potable water supply
  • Single cover for ease of maintenance
  • Top mounted test cocks
  • No special tools required for servicing
  • Maximum working pressure: 175 psi
  • Meets lead-free legislation requirements
  • Click here for dimensions

Series 007
Size Body QT NRS OSY
1/2" Bronze $420.15 -- --
3/4" Bronze $471.18 -- --
1" Bronze $539.45 -- --
1-1/4" Bronze $793.42 -- --
1-1/2" Bronze $997.30 -- --
2" Bronze $1110.68 -- --
2-1/2" Iron $2097.20 $3696.02 $4071.70
3" Iron $2311.74 $4074.87 $4676.62

- Or -
View Button



Series 007 Double Check Valve Backflow Preventer
Stainless Steel w/ Quarter Turn Shutoff
picture of the stainless steel Watts double check backflow preventer series 007
    This double check valve features:
  • Cast 316 stainless steel assembly is designed for corrosion resistance, making it ideal in applications where bronze valves are undesirable
  • Typical low-hazard installations may be found in industrial or chemical plants, pulp and paper industries, hospitals, and corrosive atmospheres
  • Nonreversible checks with captured springs prevents the backflow of polluted water from contaminating the potable water supply
  • Bolted on, top entry single access cover for ease of maintenance
  • Top mounted vandal resistant test cocks include dust covers to protect the threads from dirt, dust and insects
  • No special tools required for servicing
  • Maximum working pressure: 175 psi
  • Meets lead-free legislation requirements
  • Click here for detailed dimensions

Series 007 Stainless Steel
Size Price & Quantity
1/2" $1494.80
3/4" $1568.50
1" $2093.01

- Or -
View Button



709 Series Double Check Valve Backflow Preventer
photo of the 709 series double check back flow preventer by Watts
Shown: #709 with shutoff valves
    This double check valve assembly features:
  • Prevents the reverse flow of polluted water from entering the potable water supply
  • FDA approved epoxy coated cast iron body construction
  • Maximum flow at low pressure drop
  • Design simplicity for easy maintenance
  • No special tools required for servicing
  • Captured spring assemblies for safety
  • Approved for vertical flow up installation
  • Available in a variety of valve configurations
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • Click here for dimensions

Series 709 Iron Body
Size OSY NRS LESS valves
2-1/2" $4665.91 $4393.34 $3061.52
3" $5351.04 $4791.15 $3376.96
4" $5937.08 $5312.94 $3863.85
6" $9348.61 $8559.97 $6324.37
8" $15335.82 $15083.43 $12560.87
10" $20313.06 $18714.40 $15383.81
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 719 Double Check Valve Backflow Preventer
w/ Quarter Turn Shutoff
picture of the Watts double check backflow preventer series 719
    This double check valve features:
  • Non-reversible checks with captured springs prevents the backflow of polluted water from contaminating the potable water supply
  • Plastic on plastic check guiding reduces potential binding due to mineral deposits
  • Separate access, top entry check valve design
  • Reversible seat disc rubber extends check valve life
  • Chloramine resistant elastomers
  • Compact design allows for efficient installation
  • 1/2", 3/4", and 1" sizes have tee handles
  • No special tools required for servicing
  • Maximum working pressure: 175 psi
  • Meets lead-free legislation requirements
  • Click here for detailed dimensions

Series 719
Size Price & Quantity
1/2" $400.97
3/4" $451.80
1" $511.23
1-1/4" $752.88
1-1/2" $944.50
2" $1058.64

- Or -
View Button



Series 757 Double Check Backflow Preventer
image of the Watts 757 OSY backflow preventer
Shown: 757OSY
    This double check valve assembly features:
  • Protects against both back pressure and back siphonage, preventing backflow from entering into the potable water supply
  • Compact housing is 70% lighter than traditional designs
  • Suitable for installation under continuous pressure service
  • 304 Schedule 40 stainless steel housing and quick-access sleeve
  • Approved for horizontal, vertical, or "N" pattern installations
  • Patented link-check assemblies allow ease of serviceability
  • Four test cocks
  • No special tools needed for servicing
  • Complies with lead free legislation
  • Maximum working pressure 175psi

Series 757 Stainless Steel
Size NRS OSY Butterfly LESS valves
2-1/2" $3031.98 $3241.96 $3573.00 $3181.14
3" $3360.70 $3579.10 $3880.38 $3516.94
4" $3718.05 $3909.47 $4243.50 --
6" $5960.54 $6137.51 $6435.47 --
8" $11951.40 $12045.55 $10364.77 --
10" $12200.65 $13293.39 -- --
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 757N Double Check Backflow Preventer
image of the Watts 757 OSY backflow preventer
Shown: 757N OSY
    This double check valve assembly features:
  • Protects against both back pressure and back siphonage, preventing backflow from entering into the potable water supply
  • Compact housing is 70% lighter than traditional designs
  • Suitable for installation under continuous pressure service
  • 304 Schedule 40 stainless steel housing and quick-access sleeve
  • Approved for horizontal, vertical, or "N" pattern installations
  • Patented link-check assemblies allow ease of serviceability
  • Four test cocks
  • No special tools needed for servicing
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • click here for detailed dimensions

Series 757N Stainless Steel
Size NRS OSY Butterfly LESS valves
2-1/2" $4288.00 $4624.75 $4993.96 $4278.45
3" $4633.21 $5003.40 $5283.96 $4635.27
4" $5770.33 $6158.97 $6463.90 --
6" $9432.89 $9789.66 $10171.84 --
8" $15199.95 $15769.11 $13097.47 --
10" $16645.71 $16125.57 -- --
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 774 Double Check Backflow Preventer
picture of the backflow preventer Watts series 774
Shown: 774OSY
    This double check valve features:
  • Prevents contamination of potable water systems from backflow of non-potable water
  • Ideal in applications by local authorities as non-health hazard, such as commercial swimming pools
  • Stainless steel construction provides long term corrosion protection and maximum strength
  • Compact design and short lay length makes it a great choice for retrofit installations
  • Patented torsion spring check valve provides low head loss
  • Single top access cover with two-bolt grooved style coupling for ease of maintenance
  • No special tools required for servicing
  • May be installed in horizontal or vertical "flow up" position
  • Available with OSY valves (outside stem yoke) with grooved inlet/flanged outlet or flanged inlet/grooved outlet
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • Click here for dimensions

Series 774 Stainless Steel
Size NRS OSY OSY GxF OSY FxG LESS valves
2-1/2" $3492.66 $3499.98 $3489.09 $3492.20 $2285.60
3" $3855.38 $4005.99 $4015.77 $4011.31 $2505.21
4" $4038.11 $4145.69 $4142.47 $4154.89 $2670.15
6" $6518.19 $6442.02 $6475.81 $6463.59 $4391.17
8" $13008.79 $12814.51 $11759.07 $11747.70 $9441.51
10" $15356.23 $14667.17 $11759.07 $15598.64 $11131.69
12" $19725.37 $19375.40 -- -- $14333.98
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 009 Reduced Pressure Zone Backflow Preventer
w/ Quarter Turn Valves
image of the Watts 009QT backflow preventer
Shown: 009 QT
    This backflow preventer features:
  • Designed to protect potable water supplies as required by national plumbing codes and water authority requirements
  • Large body passages provides low pressure drop
  • Compact, space saving design
  • Single access cover and modular check construction for ease of maintenance
  • Top entry so all internals are immediately accessible
  • Internal relief valve for reduced installation clearances
  • Screwdriver slotted ball valve test cocks
  • No special tools required for servicing
  • Complies with lead free legislation
  • Maximum working pressure: 175 psi
  • Click for internal diagram
  • Click here for detailed dimensions

Series 009
Size Body QT NRS OSY
1/2" Bronze $622.50 -- --
3/4" Bronze $828.44 -- --
1" Bronze $979.42 -- --
1-1/4" Bronze $1538.37 -- --
1-1/2" Bronze $1612.17 -- --
2" Bronze $1901.47 -- --
2-1/2" Bronze -- $4903.74 $4539.15
3" Bronze -- $5693.45 $5105.63
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 009 Reduced Pressure Zone Backflow Preventer
Stainless Steel w/ Quarter Turn Valves
image of the stainless steel Watts 009 backflow preventer
    This backflow preventer features:
  • Designed to protect potable water supplies as required by national plumbing codes and water authority requirements
  • Durable cast 316 stainless steel assembly is designed for corrosion resistance, making it ideal in applications where bronze valves may be damaged
  • Typical applications are industrial or plant use, carbonated beverage machines, breweries/distilleries, paper and pulp industry, chemical plants and aggressive atmospheres
  • Large body passages provides low pressure drop
  • Constructed with NPT body connections
  • Bolted on, top entry single access cover for ease of maintenance
  • Stainless steel, top-mounted, vandal-resistant EZ-TC test cocks with dust covers provide easy access for testing
  • Internal relief valve for right and left hand installations
  • No special tools required for servicing
  • Complies with lead free legislation
  • Maximum working pressure: 175 psi
  • Click for dimensions

Series 009 Stainless Steel
Size Price & Quantity
1/4" $1947.98
3/8" $2047.49
1/2" $2090.66
3/4" $2255.10
1" $2358.26

- Or -
View Button



Series 919 Reduced Pressure Zone Backflow Preventer
w/ Quarter Turn Valves
image of the Watts 919 reduced pressure backflow preventer
    This reduced pressure backflow preventer features:
  • A pressure differential relief valve is located in a zone between two positive-seating check valves to prevent backflow due to back siphonage and/or back pressure
  • Compact, space saving design
  • Separate access covers for the check valves and relief valve for ease of maintenance
  • Top entry so all check internals are easily accessible
  • All rubber elastomers of chloramine resistant material
  • Check valve poppet assemblies are fully guided by innovative plastic seat guide
  • Bottom mounted relief valve provides reduced installation clearances
  • NPT body connections
  • No special tools required for servicing
  • Complies with lead free legislation
  • Maximum working pressure: 175 psi
  • Click for dimensions

Series 919
Size Price & Quantity
3/4" $787.75
1" $933.20
1-1/4" $1453.26
1-1/2" $1531.02
2" $1802.84

- Or -
View Button



Series 909 Bronze Reduced Pressure Zone Backflow Preventer
image of the Watts 909 reduced pressure backflow preventer
Shown: 909QT
    This reduced pressure backflow preventer features:
  • A pressure differential relief valve located in a zone between two positive seating check valves prevents back siphonage and back pressure of hazardous materials into the potable water supply
  • Model HW includes stainless steel check modules suitable for temperatures up to 210°F and harsh water conditions
  • Sizes 3/4" and 1" shutoffs have tee handles
  • Compact design for ease of installation
  • Designed for horizontal or vertical installations
  • No special tools required for servicing
  • NPT threaded connections
  • Complies with lead free legislation
  • Maximum working pressure: 175 psi
  • Click for dimensions

Series 909
Size QT HW
3/4" $1379.30 $2009.56
1" $1635.06 $2375.21
1-1/4" $2576.79 $3717.42
1-1/2" $2776.60 $4027.31
2" $3196.07 $4599.41

- Or -
View Button



Series 909 Iron Reduced Pressure Zone Backflow Preventer
image of Watts reduced pressure backflow preventer series 909 with NRS configuration
Shown: 909NRS
    This reduced pressure zone assembly features:
  • Designed to prevent back siphonage and back pressure backflow of hazardous materials into the potable water supply
  • Air-in/water out relief valve design provides maximum capacity during emergency conditions
  • FDA approved epoxy coated cast iron body
  • Stainless steel internal parts
  • Industrial strength sensing hose
  • Field reversible relief valve
  • No special tools required for servicing
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • Click for dimensions

Series 909 Iron Body
Size NRS OSY LESS valves
2-1/2" $5828.04 $6026.18 $4754.33
3" $6586.32 $7001.84 $5351.34
4" $7990.03 $8223.07 $6722.86
6" $11669.18 $12144.81 $9918.78
8" $18237.20 $18903.84 $16259.91
10" $23742.86 $26062.57 $21379.29
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 957 Reduced Pressure Backflow Preventer
image of the Watts model 957, show with OSY configuration
Shown: Model 957 OSY
    This reduced pressure backflow preventer features:
  • Prevents the reverse flow of polluted water from entering into the potable water supply due to back siphonage and/or back pressure
  • Utilizes groove connections for ease of installation and pipe alignment
  • Patented torsion spring check modules for lowest pressure loss
  • Compact design allows for small enclosures to be used
  • Bottom mounted cast stainless steel relief valve
  • Entire valve body and closure manufactured from 300 series stainless steel
  • Quarter-turn ball valve series offers fast operation with low operating torque
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • Click for dimensions

Model 957
Size OSY NRS NRS w/ cast iron strainer QT
2-1/2" $4131.92 $3407.55 $3936.78 $3605.87
3" $4602.48 $4179.58 $4806.28 $4401.74
4" $5100.95 $4810.68 $5882.90 --
6" $8116.84 $7633.48 $9641.73 --
8" $12042.80 $11636.97 $13914.73 --
10" $15267.46 $13449.26 $17899.90 --
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 957N Reduced Pressure Backflow Preventer
image of the Watts model 957n, shown with butterfly valve shutoffs
Shown: Model 957N BFG
    This reduced pressure backflow preventer features:
  • Prevents back siphonage and/or back pressure to keep contaminated water away from the potable water supply
  • Patented torsion spring check modules for lowest pressure loss
  • Compact design allows for wider variety of installation options
  • Bottom mounted cast stainless steel relief valve
  • Entire valve body and closure manufactured from 300 series stainless steel
  • Quarter-turn ball valves for quick operation
  • Butterfly valves have built in tamper switch wiring and flow indicator flag
  • Groove fittings allow integral pipeline adjustment
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • Click for dimensions

Model 957N
Size OSY NRS BFG QT
2-1/2" $5530.69 $4802.81 $6094.62 $3605.87
3" $6033.09 $5598.31 $6682.30 $5611.99
4" $7334.46 $7058.89 $8100.22 --
6" $11931.32 $11352.38 $12031.38 --
8" $14141.37 $12991.19 -- --
10" $17587.71 $15212.36 -- --
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 957Z Reduced Pressure Backflow Preventer
image of the Watts model 957z, shown with butterfly shutoffs
Shown: Model 957Z BFG
    This reduced pressure backflow preventer features:
  • Prevents the reverse flow of polluted water from entering into the potable water supply due to back siphonage and/or back pressure
  • Patented torsion spring check modules for lowest pressure loss
  • Compact design allows for small enclosures to be used
  • Bottom mounted cast stainless steel relief valve
  • Entire valve body and closure manufactured from 300 series stainless steel
  • Quarter-turn ball valve series offers fast operation with low operating torque
  • Butterfly valves have built in tamper switch wiring and flow indicator flag
  • Groove fittings allow integral pipeline adjustment
  • Complies with lead free legislation
  • Maximum working pressure 175psi
  • Click for dimensions

Series 957Z
Size OSY NRS BFG QT
2-1/2" $5520.84 $4802.81 $6072.27 $4776.18
3" $6046.54 $5618.83 $6629.77 $5579.65
4" $7327.91 $7015.11 $8100.22 --
6" $11923.39 $10325.86 $12005.24 --
8" $15084.87 $13024.54 -- --
10" $17429.84 $15313.60 -- --
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Series 994 Reduced Pressure Backflow Preventer
image of the Watts model 994, show with OSY configuration
Shown: Model 994 OSY
    This reduced pressure backflow preventer features:
  • Designed to provide protection of the potable water supply in accordance with national codes
  • Stainless steel construction provides long term corrosion resistance and maximum strength
  • Short end-to-end dimensions make this model a great choice for retrofit installations
  • Compact construction allows for smaller enclosures
  • Bottom mounted relief valve reduces clearance requirements when installed against an outside wall
  • Patented torsion spring check valves provides maximum flow at low pressure drop
  • Thermoplastic and stainless steel check valves for trouble-free operation
  • No special tools required for servicing
  • Available with OSY valves (outside stem yoke) with grooved inlet/flanged outlet or flanged inlet/grooved outlet
  • Complies with lead free legislation
  • Maximum working pressure 175psi

Model 994 Stainless Steel
Size NRS OSY OSY GxF OSY FxG LESS valves
2-1/2" $4103.07 $4416.18 $4417.65 $4393.21 $3234.64
3" $4628.78 $5127.64 $5106.60 $5131.05 $3687.01
4" $5339.09 $5679.51 $5666.30 $5658.75 $4357.70
6" $8450.10 $8976.51 $8964.49 $9029.56 $7042.14
8" $12841.84 $13861.60 $14835.30 $13830.04 $11395.80
10" $17715.11 $17529.40 $17424.27 $17421.88 $13635.90
 
Due to weight and to ensure safe delivery, these items ship by truck and have a $175 additional shipping fee.
Please select your type of address: Commercial -or- Residential

- Or -
View Button



Pressure Vacuum Breakers For Sprinkler Systems
example of a small Watts pressure vacuum breaker
    This vacuum breaker features:
  • For use with sprinkler systems
  • Bronze body
  • Silicon rubber check valve disc
  • Plastic check valve seat
  • Stainless steel springs
  • Lightweight plastic disc float
  • Click here for detailed dimensions
Size Price & Quantity
1/2" $109.73
3/4" $156.36
1" $168.11
1-1/4" $339.75
1-1/2" $313.57
2" $354.59

- Or -
View Button



need any pipe thread sealing tape?



Woodford Double Check Backflow Preventers
example of a hose threaded backflow preventer
# 50H
    This backflow preventer features:
  • Prevents backflow contamination and freezing by automatically draining when hose is removed
  • 120°F maximum temperature rating
  • Maximum pressure 125 p.s.i.
  • 3/4" male hose outlet connection
  • 3/4" female hose inlet connection
  • Available in brass and chrome finishes

Model Description Chrome Brass
50H 3/4" FHT x 3/4" MHT Backflow Preventer $24.83 $20.50

- Or -
View Button



Brass Vacuum Breaker
image of a simple brass hose bibb vacuum breaker
Click here for larger image
Brass vacuum breaker for hose bibbs = $3.69

Order 12 or more brass vacuum breaker hose bibbs for additional savings.
Order 100 or more brass vacuum breaker hose bibbs for even greater savings.
volume pricing will show up in your shopping cart

- Or -
View Button

to standard check valves



PTFE Thread sealing tape:
photo of PTFE thread sealing tape
1/2" x 260" = $0.79

- Or -
View Button



Frequently Asked Questions

Q. "Where would I find double check backflow preventer valves?"
A. Double check valve assembly backflow preventers are often found on water lines servicing fire sprinkler systems, commercial swimming pools, water treatment tanks, to name a few. Local code will specify what items in your area requires which specific type of backflow prevention device. Always consult your local code authorities with any questions regarding backflow prevention.

Q. "I'm hearing a lot about lead-free these days. What does that have to do with plumbing products and how does the new lead-free legislation affect me?"
A. Basically, the laws implemented Jan. 1st, 2014 require plumbing products that come in contact with drinking water to be essentially lead free (less than 0.25% weighted average). For further information about how the law determines what is lead free, rules regarding which plumbing products must be lead free, and who these laws will affect, please visit our LEAD FREE Plumbing Information page.

Q. "What does the term NRS and OSY mean?"
A.This means the inlet and outlet gate valves have a "non rising stem" (NRS) or "outside stem and yoke" (OSY). The non rising stem allows a more compact installation if there are height restrictions. For instance, installing these valve assemblies into a valve box. The outside stem and yoke gate valves rise upwards as rotated to the open position. The outside stem and yoke valves are preferred in some instance because it is easier to see from a distance if the valves are open or closed.

Q. "What is a test cock?"
A.Test Cocks are used to facilitate backflow assembly testing or as isolation valves for gauges or small equipment lines.



return to top ↑

We hope that we have helped you on this page with backflow prevention products,
and thank you for helping to make PlumbingSupply.com® the most famous Internet plumbing supplier.


Fun, inspirational quote of the day:
"Logic will get you from A to B. Imagination will take you everywhere."
- Albert Einstein



Is there something else that you are looking for?

Enter search terms:

OR - find plumbing supplies starting with: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z



Easy payment methods