The Watts LF9D is a compact, dual check valve backflow preventer designed for non-health hazard applications in small supply lines—ideal for boiler feeds, lab equipment, dairies, and more. Made from a lead-free forged brass body and stainless steel internal components, it features two independent rubber-seated check valves with an intermediate atmospheric vent to guard against backflow when fouling occurs. Its inline, union-connected design allows installation vertically or horizontally, aiding maintenance. It operates continuously with a pressure range from 25 psi minimum to 175 psi maximum and withstands temperatures from 33°F to 250°F, offering reliable and maintenance-friendly protection in compact installations.

Technical Specifications

• Size Range: ½″ and ¾″

• Materials:

  • Body: Lead-free forged brass

  • Internals: Stainless steel and rubber disc check valves

• Pressure Rating: 25 psi minimum to 175 psi maximum

• Temperature Range: 33°F – 250°F

• Installation: Inline union-type, suitable for vertical or horizontal mounting; includes atmospheric vent and integral strainer