About Backflow-Prevention Valves
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Easy-Maintenance Threaded Two-Stage
Backflow-Prevention Valves for Drinking Water
- For Use With: Drinking Water
- Seal Material: Buna-N Rubber
Integral shutoff valves isolate flow for inline maintenance, and a top-entry cover provides easy access to internal components. These valves meet NSF/ANSI 61 for use with drinking water. For maximum protection from system contamination, they consist of a primary check valve and a secondary check valve. If the first check fails to close when flow stops or reverses, the secondary check valve engages to prevent backflow. A strainer prevents debris from blocking the check valves.
| Pipe Size  | Max. Pressure | Min. Opening Pressure, psi | Temperature Range, °F | End-to-End Lg. | Features | Specifications Met | Each | |
Bronze Body—Dual-Check Valve | ||||||||
|---|---|---|---|---|---|---|---|---|
NPT Female × NPT Female | ||||||||
| 1/2 | 175 psi @ 180° F | 30 | 35° to 180° | 12 3/4" | Strainer | ASSE 1015, CSA Certified, NSF/ANSI 61, USC Foundation Approved | 0000000 | 0000000 |
| 3/4 | 175 psi @ 180° F | 30 | 35° to 180° | 14 5/16" | Strainer | ASSE 1015, CSA Certified, NSF/ANSI 61, USC Foundation Approved | 0000000 | 000000 |
| 1 | 175 psi @ 180° F | 30 | 35° to 180° | 17" | Strainer | ASSE 1015, CSA Certified, NSF/ANSI 61, USC Foundation Approved | 0000000 | 000000 |
| 1 1/2 | 175 psi @ 180° F | 30 | 35° to 180° | 21 5/8" | Strainer | ASSE 1015, CSA Certified, NSF/ANSI 61, USC Foundation Approved | 0000000 | 000000 |
| 2 | 175 psi @ 180° F | 30 | 35° to 180° | 24 13/16" | Strainer | ASSE 1015, CSA Certified, NSF/ANSI 61, USC Foundation Approved | 0000000 | 00000000 |
Threaded Two-Stage Backflow-Prevention Valves for Drinking Water
- For Use With: Drinking Water
- Seal Material: EPDM Rubber
Keep backflow from contaminating your drinking water supply—these valves meet NSF/ANSI 61 for use with drinking water. They consist of a primary check valve and a secondary check valve. If the primary check fails to close when flow stops or reverses, the secondary check valve engages to prevent backflow.
Single-union valves have a union fitting on one end.
Double-union valves have a union fitting on both ends.
For technical drawings and 3-D models, click on a part number.
| Pipe Size | Max. Pressure | Min. Opening Pressure, psi | Temperature Range, °F | End-to-End Lg. | Each | |
Brass Body—Single Union | ||||||
|---|---|---|---|---|---|---|
NPT Female Inlet × NPT Female Outlet | ||||||
| 3/4 | 175 psi @ 180° F | 5 | 35° to 180° | 3 3/4" | 00000000 | 000000 |
| 1 | 175 psi @ 180° F | 5 | 35° to 180° | 3 3/4" | 00000000 | 000000 |
NPT Male Inlet × NPT Female Outlet | ||||||
| 3/4 | 175 psi @ 180° F | 5 | 35° to 180° | 3 3/4" | 00000000 | 000000 |
Brass Body—Double Union | ||||||
NPT Female Inlet × NPT Female Outlet | ||||||
| 1/2 | 175 psi @ 180° F | 5 | 35° to 180° | 3 3/4" | 0000000 | 000000 |
| 3/4 | 175 psi @ 180° F | 5 | 35° to 180° | 3 3/4" | 0000000 | 000000 |
| 1 | 175 psi @ 180° F | 5 | 35° to 180° | 4" | 0000000 | 000000 |
Threaded Two-Stage Backflow-Prevention Valves
- For Use With: Air, Water
- Disc Material: EPDM Rubber
- Seal Material: EPDM Rubber
For maximum protection from system contamination, these valves have two integral check valves with a vent between them. If the primary check valve fails to close when flow stops or reverses, overflow is discharged through the vent and the secondary check valve prevents backflow.
Strainers prevent debris from blocking the check valves.
Chrome-plated brass valve is more corrosion resistant than plain brass valves.
Valve with an unthreaded vent is commonly used on laboratory faucets and other applications with intermittent flow. It discharges overflow directly and should not be installed in areas where spillage could cause water damage.
Valves with a threaded vent can be connected to drain pipes to prevent spillage. They are designed for applications with continuous flow and are often installed on water supply lines to boilers, processing tanks, and other equipment.
For technical drawings and 3-D models, click on a part number.
| Pipe Size | Max. Pressure | Min. Opening Pressure, psi | Temperature Range, °F | End-to-End Lg. | Vent Type | Features | Each | |
Brass Body | ||||||||
|---|---|---|---|---|---|---|---|---|
NPT Female Inlet × NPT Female Outlet | ||||||||
| 1/2 | 175 psi @ 250° F | 25 | 35° to 250° | 4 15/16" | Threaded | Strainer | 0000000 | 0000000 |
| 3/4 | 175 psi @ 250° F | 25 | 35° to 250° | 4 1/2" | Threaded | Strainer | 0000000 | 000000 |
Chrome-Plated Brass Body | ||||||||
NPT Male Inlet × NPT Female Outlet | ||||||||
| 3/8 | 150 psi @ 140° F | 25 | 35° to 140° | 2 3/8" | Unthreaded | __ | 0000000 | 000000 |
Two-Stage Backflow-Prevention Valves with Solder-Connect Fittings
- For Use With: Air, Water
- Disc Material: EPDM Rubber
- Seal Material: EPDM Rubber
Solder these valves to copper tubing for a permanent, leak-tight connection. They have two integral check valves with a vent between them for maximum protection from system contamination. If the primary check valve fails to close when flow stops or reverses, overflow is discharged through the threaded vent and the secondary check valve prevents backflow. Attach the vent to drain pipes to prevent spillage. These valves are designed for applications with continuous flow and are commonly used on water supply lines to boilers, processing tanks, and other equipment. All have an integral strainer to prevent debris from blocking the check valves.
For technical drawings and 3-D models, click on a part number.
Vent Port | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| For Copper Tube Size | For Tube OD | Max. Pressure | Min. Opening Pressure, psi | Temperature Range, °F | End-to-End Lg. | Vent Type | Gender | Pipe Size | Thread Type | Features | Each | |
Brass Body | ||||||||||||
Solder Connect × Solder Connect | ||||||||||||
| 1/2 | 5/8" | 175 psi @ 250° F | 25 | 35° to 250° | 4 3/8" | Threaded | Female | 1/2 | NPT | Strainer | 0000000 | 0000000 |
| 3/4 | 7/8" | 175 psi @ 250° F | 25 | 35° to 250° | 4 13/16" | Threaded | Female | 1/2 | NPT | Strainer | 0000000 | 000000 |