Watts LF909-QT-FS 3/4" RPZ Backflow Preventer Valve [F391008].
Product Overview:
The Watts LF909-QT-S-FS 3/4" Reduced Pressure Zone Assembly is engineered to prevent backflow caused by both backsiphonage and backpressure conditions. It includes two check valves and a differential pressure relief valve positioned between them. When both checks fail, the relief valve discharges to atmosphere using Watts’ patented air-in/water-out technology, minimizing contamination risk.
Standard features include:
-
Compact, space-efficient body with full-port quarter-turn shutoff valves
-
Integrated stainless steel relief valve with sensor for flood monitoring
-
Replaceable check valve seats and no special tools required for maintenance
-
Certified for both vertical (flow-up) and horizontal installations
-
Lead-free compliance (≤0.25% lead content)
Product Specifications:
-
Model: LF909-QT-S-FS
-
Size: 3/4"
-
Connection Type: NPT Female Threaded
-
Max Working Pressure: 175 psi (12.1 bar)
-
Temperature Range: 33°F – 140°F continuous, 180°F intermittent
-
Material Construction: Lead-Free Cast Copper Silicon Alloy
-
Certifications: ASSE 1013, AWWA C511, CSA B64.4, NSF, IAPMO, SBCCI
-
Flow Rate Capacity: Up to 18 GPM at 10 psi pressure drop
-
Includes: Quarter-turn shutoff valves, integrated bronze strainer, sensor-equipped relief valve
Installation Tips:
-
Install in a high-visibility location to easily spot discharge and enable regular testing
-
Avoid pit or vault installations; always maintain an air gap below the relief valve port
-
Use a properly sized strainer upstream (avoid for emergency lines like fire sprinklers)
-
Ensure test cocks are accessible and never install the valve in concealed locations
-
Allow gradual filling to avoid damaging internal O-rings during startup
-
For outdoor use in cold climates, install in an insulated WattsBox® enclosure
-
Always have the unit tested by a certified backflow tester after installation
FAQs:
Q: Can this be installed vertically?
Yes. The LF909 3/4" is approved for both horizontal and vertical (flow-up) installation.
Q: Is the flood sensor active out of the box?
Not by default. A sensor connection kit is required for BMS or cellular alert integration.
Q: Is maintenance difficult?
Not at all. Seats are replaceable and accessible with no special tools required.
Q: How often should it be tested?
Annually at minimum—or more frequently as required by local codes or usage.
Technical Downloads:
- Watts LF909-QT-FS RPZ: Specification Submittal
Ready to Order?
Get the dependable, code-compliant protection your system needs. Order the Watts LF909 3/4" RPZ Backflow Preventer today and ensure safe, uninterrupted water supply across your facilities.
Shop now at MasterBuilderMercantile.com – Your source for Watts RPZ valves, backflow preventers, and commercial plumbing essentials.
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
