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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
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

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Series 007 Double Check Valve Backflow Preventer Stainless Steel w/ Quarter Turn Shutoff

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

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709 Series Double Check Valve Backflow Preventer
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"	$18335.82	$17083.43	$13560.87
10"	$25313.06	$22714.40	$17383.81

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Series 719 Double Check Valve Backflow Preventer w/ Quarter Turn Shutoff

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

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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	$12364.77	--
10"	$15200.65	$15293.39	--	--

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Series 757N Double Check 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

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"	$17199.95	$17769.11	$13097.47	--
10"	$20645.71	$21125.57	--	--

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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

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	$12759.07	$12747.70	$9441.51
10"	$17356.23	$17667.17	$12759.07	$17598.64	$12131.69
12"	$24725.37	$24375.40	--	--	$17333.98

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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
2-1/2"	Bronze	--	$5693.45	$5105.63

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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

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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

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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

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

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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"	$12669.18	$13144.81	$10918.78
8"	$22237.20	$22903.84	$19259.91
10"	$29742.86	$33062.57	$25379.29

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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"	$14042.80	$13666.97	$16914.73	--
10"	$17267.46	$16449.26	$21899.90	--

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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	$13031.38	--
8"	$18141.37	$14991.19	--	--
10"	$21587.71	$18212.36	--	--

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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	$11325.86	$13005.24	--
8"	$18084.87	$15024.54	--	--
10"	$21429.84	$18313.60	--	--

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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"	$14841.84	$15861.60	$15835.30	$15830.04	$12395.80
10"	$19715.11	$21529.40	$21424.27	$21421.88	$16235.90

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Pressure Vacuum Breaker
	This vacuum breaker features: 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"	$116.36
1"	$126.11
1-1/4"	$281.42
1-1/2"	$313.57
2"	$354.59

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need any pipe thread sealing tape?

Woodford Double Check Backflow Preventers
# 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 Available in brass and chrome finishes

Model	Description	Chrome	Brass
50H	3/4" FHT x 3/4" MHT Backflow Preventer	$24.83	$20.50
50HA	Fits Woodford 27 - 1-1/8" special thread inlet x 3/4" MHT outlet	$24.94	$20.46
50HF	Fits Woodford faucets: 26, B26, Y26, Y2, and H34 - 13/16" special thread inlet x 3/4" MHT	$24.79	$20.44

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PTFE Thread sealing tape:

1/2" x 260" = $0.38

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Brass Vacuum Breaker

image of a simple brass hose bibb vacuum breaker

Click here for larger image

Brass vacuum breaker for hose bibbs = $3.49

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

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to standard check valves

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. "What does it mean to have ANSI Certification for lead free plumbing products?"
A. Laws requiring plumbing products that come in to contact with drinking water to be essentially lead-free (0.25% weighted average) have been passed in California and Vermont. In order for companies to ship these plumbing products to locations in CA and VT, they must be ANSI certified lead free.

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.

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Double Check Backflow PreventersBy Watts

Double Check Backflow Preventers
By Watts