About Backflow-Prevention Valves
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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.
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.
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 |