
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:
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Compact, space-efficient body with full-port quarter-turn shutoff valves
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Integrated stainless steel relief valve with sensor for flood monitoring
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Replaceable check valve seats and no special tools required for maintenance
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Certified for both vertical (flow-up) and horizontal installations
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Lead-free compliance (≤0.25% lead content)
Product Specifications:
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Model: LF909-QT-S-FS
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Size: 3/4"
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Connection Type: NPT Female Threaded
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Max Working Pressure: 175 psi (12.1 bar)
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Temperature Range: 33°F – 140°F continuous, 180°F intermittent
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Material Construction: Lead-Free Cast Copper Silicon Alloy
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Certifications: ASSE 1013, AWWA C511, CSA B64.4, NSF, IAPMO, SBCCI
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Flow Rate Capacity: Up to 18 GPM at 10 psi pressure drop
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Includes: Quarter-turn shutoff valves, integrated bronze strainer, sensor-equipped relief valve
Installation Tips:
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Install in a high-visibility location to easily spot discharge and enable regular testing
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Avoid pit or vault installations; always maintain an air gap below the relief valve port
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Use a properly sized strainer upstream (avoid for emergency lines like fire sprinklers)
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Ensure test cocks are accessible and never install the valve in concealed locations
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Allow gradual filling to avoid damaging internal O-rings during startup
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For outdoor use in cold climates, install in an insulated WattsBox® enclosure
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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.
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