4 957NRPDA-OSY-GPM-FS

Item Number: F111640
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$13,783.92
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Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Product Type: Reduced Pressure Detector Backflow Preventer
  • Weight: 266.0 lb
  • Size: 4 inch
  • Body Material: 304 (Schedule 40) Stainless Steel
  • Shutoff Valves: OSY Resilient Seated Gate Valves
  • Installation Pattern: Horizontal N Pattern
  • Includes: Gallon Per Minute (GPM) Meter
  • Flood Sensor: Integrated SentryPlus Alert® Technology
  • Maximum Working Pressure: 175 psi

Description

The Watts 4 inch 957NRPDA Reduced Pressure Detector Assembly is a compact, lightweight backflow preventer for horizontal N pattern installation, protecting potable water from contamination. Constructed with 304 stainless steel, it features OSY gate valves, a bottom-mounted relief valve, and a gallon per minute meter for leak detection. An integrated flood sensor with SentryPlus Alert® technology detects excessive water discharge, offering notification capabilities when paired with an add-on connection kit. Approved by ASSE, AWWA, CSA, UL, and FM, it operates at a maximum of 175 psi within a 33°F to 140°F temperature range. Item number F111640.

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Connection and Installation

  • This Watts Series 957NRPDA assembly is designed for 4 inch connections and is specifically approved for horizontal N pattern installation.
  • The shutoff valves are UL Classified and FM Approved outside stem and yoke resilient seated gate valves, facilitating connection and isolation.
  • An add-on sensor connection kit is required to activate the flood sensor's communication capabilities. Without this kit, the sensor is passive. Kit options include BMS, cellular communication, or the Sensor Control Monitor for integration with BAS via RS-485 Modbus or Nexa® Wi-Fi.
  • Consult local water authority, building, and plumbing codes for specific installation requirements.
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Additional Details

The Watts 4 inch Series 957NRPDA Reduced Pressure Detector Backflow Preventer Assembly is designed to protect potable water systems from contamination due to back-siphonage or backpressure, particularly where health hazards may exist. This assembly is approved for horizontal N pattern installation and is notably more compact and lighter than traditional designs.

This backflow preventer features a stainless steel body with a quick access sleeve, torsion spring check valves, and resilient seated gate valves with Outside Stem and Yoke (OSY). It includes a corrosive-resistant bottom-mounted pressure relief valve and is furnished with a gallon per minute meter for detecting underground leaks or unauthorized water use. A key feature is the integrated flood sensor with SentryPlus Alert® technology, which detects excessive water discharges from the relief valve. When an add-on connection kit is paired, the sensor activates to relay alerts for potential flooding events, compatible with BMS, cellular communication, or the Sensor Control Monitor for integration via RS-485 Modbus or Nexa® Wi-Fi platform.

A WARNING: It is illegal to use this product in any plumbing system providing water for human consumption, such as drinking or dishwashing, in the United States. Before installing, consult your local water authority, building, and plumbing codes.

Features

  • Extremely compact design, 70% lighter than traditional designs
  • Housing and sleeve constructed from 304 (Schedule 40) stainless steel
  • UL and FM approved outside stem and yoke (OSY) resilient seated gate valves
  • Approved for horizontal N pattern installation
  • Furnished with a gallon per minute (GPM) meter for leak detection
  • Bottom mounted cast stainless steel relief valve
  • Integrated flood sensor with SentryPlus Alert® technology to detect continuous relief valve discharge
  • Flood alert feature activated with an add-on sensor connection kit for BMS, cellular, or Wi-Fi communication
  • Groove fittings allow integral pipeline adjustment
  • Patented torsion spring check provides lowest pressure loss
  • Unmatched ease of serviceability with replaceable check disc rubber

Specifications

  • Product Type: Reduced Pressure Detector Backflow Preventer Assembly
  • Series: 957NRPDA
  • Size: 4 inch
  • Body Material: 304 (Schedule 40) Stainless Steel
  • Shutoff Valves: OSY (Outside Stem & Yoke) Resilient Seated Gate Valves
  • Installation Pattern: Horizontal N Pattern
  • Meter: Gallon Per Minute (GPM) Meter
  • Flood Sensor: Integrated Flood Sensor with SentryPlus Alert® Technology

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

Pressure & Temperature

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

Certificates & Approvals

  • ASSE 1047
  • AWWA C511-97
  • CSA B64.4
  • FM Approved (**BFG & OSY Only)
  • UL Classified
  • Approved by the Foundation for Cross-Connection Control and Hydraulic Research at The University of Southern California (FCCCHR-USC)

FAQs

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

The Watts 957NRPDA assembly protects potable water systems from contamination caused by back-siphonage or backpressure, especially in health hazard applications, and monitors unauthorized water use.

What type of shutoff valves are included with this assembly?

This assembly is equipped with UL Classified and FM Approved outside stem and yoke (OSY) resilient seated gate valves.

Does this backflow preventer include a flood sensor?

Yes, it features an integrated flood sensor with SentryPlus Alert® technology to detect excessive water discharges from the relief valve. An add-on connection kit is required to activate its communication features.

What is the maximum operating pressure and temperature range for this unit?

The Watts 957NRPDA can operate at a maximum working pressure of 175 psi (12.1 bar) and within a temperature range of 33°F to 140°F (0.5°C to 60°C).

Is this backflow preventer approved for all installation orientations?

No, this specific 4-inch Watts 957NRPDA model is approved for horizontal N pattern installation only.

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