4 957-DNRS-FS

Item Number: F792321
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$17,142.26
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When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Size: 4 inch
  • Weight: 265.0 lb
  • Valve Type: Domestic Non-Rising Stem (NRS) Gate Valves
  • Housing Material: 304 Stainless Steel
  • Flood Sensor: SentryPlus Alert® technology
  • Maximum Working Pressure: 175 psi
  • Temperature Range: 33°F to 140°F
  • Installation: Horizontal
  • Approvals: ASSE 1013, CSA B64.4, NSF 61-G

Description

The 4 inch Watts Series 957 Reduced Pressure Zone (RPZ) backflow preventer is designed to protect water supplies from contamination by preventing backpressure and backsiphonage. This assembly features a durable 304 stainless steel housing and domestic non-rising stem gate valves. An integrated SentryPlus Alert® flood sensor detects excessive water discharge, with options for remote alerts via BMS, cellular, or Wi-Fi connectivity. It operates horizontally, with a maximum working pressure of 175 psi and a temperature range of 33°F to 140°F. The unit holds ASSE 1013, CSA B64.4, and NSF/ANSI 61-G certifications.

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Installation and Connectivity

  • This Watts Series 957 backflow preventer is designed for horizontal installation.
  • Ensure proper drainage is provided when installing a drain line; use 957AG air gaps for optimal performance.
  • Attach air gap brackets directly onto the flood sensor for correct operation.
  • The integrated SentryPlus Alert® flood sensor can be connected via optional add-on kits for enhanced monitoring. These kits enable integration with Building Management Systems (BMS) through RS-485 Modbus, cellular communication, or the Nexa® platform using Wi-Fi.
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Additional Details

This 4 inch Watts Series 957 Reduced Pressure Zone (RPZ) backflow preventer helps stop the reverse flow of liquids in water supply lines due to backpressure or backsiphonage, preventing potential health hazards. This compact assembly is designed for horizontal installation and features a stainless steel body with domestic non-rising stem (NRS) resilient seated gate valves.

Features

  • Equipped with a flood sensor with SentryPlus Alert® technology to detect excessive water discharge from the relief valve.
  • An add-on connection kit (not included) can extend flood monitoring, activating the sensor to relay alerts for potential flooding events.
  • Connection kit options allow integration with Building Management Systems (BMS), cellular communication, or the Nexa® platform via Wi-Fi for remote alerts.
  • Constructed with a 304 (Schedule 40) stainless steel housing and sleeve for durability and corrosion resistance.
  • Torsion spring check valves and a corrosive-resistant stainless steel bottom mounted pressure relief valve.
  • Domestic non-rising stem (NRS) resilient seated gate valves.

Specifications

  • Product Type: Reduced Pressure Zone (RPZ) Backflow Preventer
  • Series: Watts 957
  • Size: 4 inch
  • Valve Type: Domestic Non-Rising Stem (NRS) Resilient Seated Gate Valves
  • Housing & Sleeve Material: 304 (Schedule 40) stainless steel
  • Elastomer Materials: EPDM, silicone, Buna-N
  • Torsion Spring Checks Material: Noryl®, stainless steel
  • Check Discs Material: Reversible silicone or EPDM
  • Test Cocks Material: Lead Free* bronze body
  • Pins & Fasteners Material: 300 Series stainless steel
  • Springs Material: Stainless steel
  • Minimum Operating Temperature: 33°F (0.5°C)
  • Maximum Operating Temperature: 140°F (60°C)
  • Maximum Working Pressure: 175 psi (12.1 bar)
  • Installation Orientation: Horizontal

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 type of valves does this backflow preventer use?

This 4 inch Watts Series 957 RPZ backflow preventer is equipped with domestic non-rising stem (NRS) resilient seated gate valves.

What material is the housing and sleeve made from?

The housing and sleeve of this backflow preventer are constructed from durable 304 (Schedule 40) stainless steel.

Does this backflow preventer include a flood sensor?

Yes, it features an integrated flood sensor with SentryPlus Alert® technology designed to detect excessive water discharge from the relief valve.

What is the maximum operating pressure and temperature range?

The maximum working pressure is 175 psi (12.1 bar), and the operating temperature range is 33°F to 140°F (0.5°C to 60°C).

What certifications does this backflow preventer have?

This assembly is approved by FCCCHR-USC, AWWA C511-97, ASSE 1013, CSA B64.4, and NSF Certified to NSF/ANSI 61-G.

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