Watts Brass Tubular 9D-M3 1/2 Backflow Preventer 1/2in Fpt

Product Description

The WATTS BRASS TUBULAR 9D-M3 1/2 is a dual check backflow preventer with an intermediate atmospheric vent, designed for 1/2 inch female pipe thread (FPT) union inlet and outlet connections. It protects potable water systems from contamination caused by back siphonage or back pressure on boiler feed lines. ASSE and CSA certified, this device is intended for use on systems that do not contain antifreeze, rust inhibitors, or other chemicals that could compromise potable water safety. Licensed plumbers typically install this device during boiler system commissioning or service.

This backflow preventer is designed for residential and light commercial hydronic heating applications, specifically on boiler feed lines where potable water supply connects to the heating loop. It is rated for systems free of chemical additives. The dual check valve design combined with the intermediate atmospheric vent provides a reliable barrier against both back siphonage and back pressure conditions, meeting the requirements of jurisdictions that mandate ASSE-certified backflow protection on boiler connections.

Key Features

• Dual check valve design prevents backflow from both back siphonage and back pressure
• Intermediate atmospheric vent provides a physical air gap barrier between check valves
• 1/2 inch female pipe thread union inlet and outlet for easy inline installation and serviceability
• ASSE and CSA certified for use in code-compliant potable water protection applications
• Intended for systems without antifreeze, rust inhibitors, or chemical additives

Compatibility

Designed as an OEM-style replacement or new-installation backflow preventer for 1/2 inch boiler feed line connections on hydronic heating systems that use only clean potable water without chemical additives.

Installation Notes

Installation should be performed by a licensed plumber in accordance with local plumbing codes and ASSE device requirements. Shut off the water supply and depressurize the line before installing or servicing this device. Union connections allow for removal and inspection without cutting the line. Do not install on systems containing antifreeze, rust inhibitors, or any chemicals that could contaminate the potable water supply.