3 957-NRS-S-FS

Item Number: F111826
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$6,881.99
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Reduced Pressure Zone Backflow Preventer: 3 inch
  • Weight: 297.0 lb
  • Shutoff Valves: Non-rising Stem (NRS) Resilient Seated Gate Valves
  • Flood Sensor: SentryPlus Alert® technology for discharge detection
  • Housing & Sleeve: 304 (Schedule 40) Stainless Steel
  • Maximum Working Pressure: 175 psi
  • Temperature Range: 33°F to 140°F
  • Lead Free*: Wetted surface less than 0.25% lead
  • Installation: Horizontal orientation approved

Description

This 3 inch Watts Series 957 Reduced Pressure Zone Assembly Backflow Preventer protects potable water systems from contamination caused by backsiphonage or backpressure in health hazard applications. It features a durable 304 stainless steel housing, non-rising stem (NRS) gate valves, and an integral cast iron flanged strainer. A built-in SentryPlus Alert® flood sensor detects relief valve discharge, with optional connectivity kits for remote notifications. This compact, lightweight, and easily serviceable unit is approved for horizontal installation and rated for 175 psi maximum working pressure and temperatures from 33°F to 140°F.

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Connections & Installation

  • This 3 inch Series 957 Reduced Pressure Zone Assembly is designed for horizontal installation.
  • The unit features groove couplings for flexible and precise pipeline adjustment during installation.
  • The integral cast iron flanged strainer connects directly to the inlet piping.
  • For flood sensor activation and remote alerts, an add-on sensor connection kit is required (sold separately), which can integrate with Building Management Systems (BMS) or cellular networks.
  • When installing a drain line for the relief valve, utilize 957AG air gaps for proper compliance and functionality.
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Additional Details

This 3 inch Watts Series 957 Reduced Pressure Zone Assembly Backflow Preventer provides essential protection for potable water systems, safeguarding against contamination from backsiphonage and backpressure in health hazard applications.

The assembly features a flood sensor with SentryPlus Alert® technology to detect excessive water discharges from the relief valve. When an add-on connection kit is utilized (sold separately), the sensor actively relays signals to facility personnel via Building Management Systems (BMS), cellular communication, or the Nexa® platform through Wi-Fi, allowing for timely corrective action and limiting potential flooding and damage.

Construction & Design

  • Features a durable 304 (Schedule 40) stainless steel housing and sleeve for robust performance.
  • Designed to be extremely compact and up to 70% lighter than traditional designs, allowing for installation in smaller enclosures.
  • Equipped with a bottom-mounted cast stainless steel relief valve.
  • Includes non-rising stem (NRS) resilient seated gate valves for reliable shutoff.
  • Groove couplings facilitate ease of installation and integral pipeline adjustment.

Performance & Maintenance

  • Utilizes patented torsion spring checks for optimal performance and lowest pressure loss.
  • Replaceable check disc rubber ensures reliable drip-tight closure against reverse flow.
  • Designed for unmatched ease of serviceability.

Installation must comply with all required instructions, codes, and regulations. A proper drainage system is necessary in the event of discharge from the relief valve.

Specifications

  • Product Type: Reduced Pressure Zone Assembly Backflow Preventer
  • Nominal Size: 3 inch
  • Shutoff Valves: Non-rising Stem (NRS) Resilient Seated Gate Valves
  • Housing & Sleeve Material: 304 (Schedule 40) Stainless Steel
  • Strainer: Cast Iron Flanged Strainer
  • Elastomers: EPDM, Silicone, Buna-N
  • Torsion Spring Check Material: Noryl®, Stainless Steel
  • Check Disc Material: Reversible Silicone or EPDM
  • Test Cock Body Material: Lead Free* Bronze
  • Pins & Fasteners Material: 300 Series Stainless Steel
  • Spring Material: Stainless Steel
  • Temperature Range: 33°F – 140°F (0.5°C – 60°C)
  • Maximum Working Pressure: 175 psi (12.1 bar)
  • Wetted Surface Lead Content: Less than 0.25% by weight

Certificates & Approvals

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

FAQs

What is the primary purpose of this backflow preventer?

This backflow preventer is designed to protect potable water systems from contamination caused by backsiphonage or backpressure, particularly in health hazard applications.

What type of shutoff valves does this Watts Series 957 assembly use?

This specific 3-inch model is equipped with non-rising stem (NRS) resilient seated gate valves, which are known for their durability and reliable shutoff.

How does the integrated flood sensor function?

The SentryPlus Alert® flood sensor detects excessive water discharge from the relief valve. With an optional add-on connection kit, it can activate alerts and send notifications via BMS, cellular communication, or the Nexa® platform to facility personnel.

What materials are used in the construction of this backflow preventer?

The housing and sleeve are constructed from 304 (Schedule 40) stainless steel, while elastomers include EPDM, silicone, and Buna-N. Check discs are reversible silicone or EPDM, and test cocks have a Lead Free* bronze body.

Can this backflow preventer be installed vertically?

This Watts Series 957 Reduced Pressure Zone Assembly is approved for horizontal installation only. Always refer to the full installation instructions and local code requirements.

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