6 957-NRS-FS

Item Number: F111605
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$13,828.14
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Size: 6 inch
  • Weight: 402.0 lb
  • Housing Material: 304 Stainless Steel
  • Shutoff Valves: NRS Resilient Seated Gate Valves
  • Flood Sensor: SentryPlus Alert® Technology
  • Maximum Working Pressure: 175 psi
  • Temperature Range: 33°F - 140°F
  • Lead Free* Bronze Test Cocks
  • Certifications: ASSE 1013, CSA B64.4, UL, FM, NSF 61-G

Description

The Watts Series 957 6-inch Reduced Pressure Zone (RPZ) backflow preventer safeguards potable water systems from contamination caused by backpressure or backsiphonage in health hazard applications. Featuring a compact 304 stainless steel housing and non-rising stem (NRS) gate valves, it includes an integrated SentryPlus Alert® flood sensor to detect excessive relief valve discharge. This assembly is UL Classified, FM Approved, and NSF/ANSI 61-G certified, ensuring reliable performance. Its lead-free* bronze test cocks and groove fittings simplify installation and serviceability for robust water system protection. Item number F111605.

Help Me Connect

Flood Sensor Activation

  • An add-on connection kit is required to activate the flood sensor and enable alert notifications. Without this kit, the sensor is a passive component.
  • Connection kit options include compatibility with Building Management Systems (BMS), cellular communication, or the Sensor Control Monitor for integration with BAS via RS-485 Modbus or the Nexa® platform through Wi-Fi.

Drainage Connection

  • When installing a drain line for this backflow preventer, use 957AG air gaps.
  • Attach air gap brackets directly onto the flood sensor to ensure proper installation and function.
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Additional Details

This 6 inch Watts Series 957 Reduced Pressure Zone (RPZ) assembly backflow preventer protects potable water systems from contamination due to backpressure or backsiphonage, particularly in health hazard applications. Its extremely compact and lightweight design allows for horizontal installation.

The assembly includes a flood sensor with SentryPlus Alert® technology to detect continuous water discharges from the relief valve. When paired with an add-on connection kit, the sensor relays alerts to facility personnel for corrective action, helping to limit flooding and costly damage.

Construction & Design

  • Features a 304 (Schedule 40) stainless steel housing and sleeve.
  • Equipped with UL Classified and FM Approved non-rising stem (NRS) resilient seated gate valves.
  • Designed with patented torsion spring check valves that provide lowest pressure loss.
  • Groove fittings facilitate integral pipeline adjustment and ease of installation.
  • Includes a corrosive-resistant, bottom-mounted cast stainless steel relief valve.
  • Replaceable check disc rubber for simplified maintenance.
  • 70% lighter than traditional designs, offering an extremely compact footprint.
  • Lead-free* bronze body components, such as the test cocks, ensure the wetted surface contains less than 0.25% lead by weight.

Flood Sensor Features

  • SentryPlus Alert® technology detects excessive water discharges from the relief valve.
  • Requires an add-on connection kit to activate flood alerts and enable communication.
  • Compatible with Building Management Systems (BMS) and cellular network communication.
  • Can integrate with the Sensor Control Monitor for alerts via BAS (RS-485 Modbus) or the Nexa® platform through Wi-Fi.

Specifications

General

  • Product Type: Reduced Pressure Zone Assembly Backflow Preventer
  • Series: 957
  • Size: 6 inch
  • Shutoff Valves: Non-Rising Stem (NRS) Resilient Seated Gate Valves
  • Flood Sensor: Integrated with SentryPlus Alert® Technology
  • Installation Orientation: Horizontal

Materials

  • Housing & Sleeve: 304 (Schedule 40) Stainless Steel
  • Elastomers: EPDM, Silicone, Buna-N
  • Torsion Spring Checks: Noryl®, Stainless Steel
  • Check Discs: Reversible Silicone or EPDM
  • Test Cocks: Lead Free* Bronze Body
  • Pins & Fasteners: 300 Series Stainless Steel
  • Springs: Stainless Steel

Performance

  • Maximum Working Pressure: 175 psi (12.1 bar)
  • Temperature Range: 33°F - 140°F (0.5°C - 60°C)

Dimensions & Weight (Approximate)

  • Overall Length (A): 43 1/2 inches (1105 mm)
  • Height (C, NRS): 30 1/8 inches (765 mm)
  • Width (D): 16 inches (406 mm)
  • Inlet/Outlet Spacing (G): 8 1/2 inches (216 mm)
  • Relief Valve to Outlet (H): 44 3/4 inches (1137 mm)
  • Relief Valve Offset (J): 23 3/16 inches (589 mm)
  • Relief Valve to Ground (M): 13 1/16 inches (332 mm)
  • Top to Center (P): 34 1/4 inches (870 mm)
  • Weight: 317 lbs (144 kg)

Certificates & Approvals

  • Approved by: Foundation for Cross-Connection Control and Hydraulic Research at The University of Southern California (FCCCHR-USC)
  • AWWA Standard: C511-97
  • ASSE Standard: 1013
  • CSA Standard: B64.4
  • UL Classified
  • FM Approved
  • NSF Certified: NSF/ANSI 61-G

FAQs

What is the primary function of the Watts Series 957 backflow preventer?

The primary function is to protect potable water systems from contamination caused by backpressure or backsiphonage, especially in health hazard applications, by preventing the reverse flow of non-potable liquids into the clean water supply.

How does the integrated flood sensor work?

The integrated SentryPlus Alert® flood sensor detects excessive water discharges from the relief valve. To activate alerts, an add-on connection kit is required, which can then relay notifications via BMS, cellular communication, or integrate with BAS/Nexa® platforms.

What material is the housing of this backflow preventer made from?

The housing and sleeve of this backflow preventer are constructed from durable 304 (Schedule 40) stainless steel, offering excellent corrosion resistance and longevity.

What type of shutoff valves does this model use?

This 6-inch model is equipped with non-rising stem (NRS) resilient seated gate valves, which are UL Classified and FM Approved for reliable and secure operation.

Is this backflow preventer approved for potable water use?

Yes, this backflow preventer is NSF Certified to NSF/ANSI 61-G, meaning its wetted surfaces contain less than 0.25% lead by weight, making it suitable for potable water applications.

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