4 957-NRS-FS

Item Number: F111604
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$8,693.13
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Connection Size: 4 inch
  • Weight: 200.0 lb
  • Shutoff Valve Type: Non-Rising Stem (NRS)
  • Housing Material: 304 Stainless Steel
  • Features Flood Sensor with SentryPlus Alert technology
  • Maximum Working Pressure: 175 psi
  • Temperature Range: 33°F - 140°F
  • Certified Lead Free*, ASSE 1013, CSA B64.4, UL, FM, NSF/ANSI 61-G
  • Compact and lightweight design

Description

The Watts Series 957 4 inch Reduced Pressure Zone (RPZ) Assembly Backflow Preventer is engineered for health hazard applications, protecting potable water systems from contamination due to backpressure or backsiphonage. This compact and lightweight unit features a 304 stainless steel housing, non-rising stem (NRS) shutoff valves, and patented torsion spring checks. An integrated SentryPlus Alert flood sensor detects relief valve discharge, with optional add-on kits for remote alerts via BMS, cellular, or Wi-Fi. It handles pressures up to 175 psi and temperatures from 33°F to 140°F, ensuring reliable performance and ease of serviceability. Item number F111604.

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Connections and Compatibility

  • This 4 inch backflow preventer is designed for 4 inch pipe connections and is suitable for horizontal installation.
  • The non-rising stem (NRS) gate valves ensure reliable shutoff functionality.
  • For flood sensor activation and remote alerts, an add-on sensor connection kit is required. These kits support various communication methods including Building Management Systems (BMS), cellular networks, or integration with the Sensor Control Monitor for BAS via RS-485 Modbus or the Nexa platform via Wi-Fi.
  • Groove couplings simplify installation and allow for integral pipeline adjustment.
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Additional Details

This 4 inch stainless steel Reduced Pressure Zone assembly backflow preventer provides protection to the potable water system from contamination, preventing the reverse flow of liquids caused by backpressure or backsiphonage in health hazard applications.

It features a compact design, non-rising stem (NRS) shutoff valves, and an integrated flood sensor for enhanced monitoring.

Flood Sensor Features

  • Includes a flood sensor with SentryPlus Alert technology to detect continuous discharge from the relief valve.
  • Requires an add-on sensor connection kit to activate flood monitoring and relay alerts.
  • Connection kit options include BMS, cellular communication, or the Sensor Control Monitor for integration with BAS via RS-485 Modbus or the Nexa platform via Wi-Fi.

Construction & Design

  • 304 (Schedule 40) stainless steel housing and sleeve.
  • Extremely compact design, up to 70% lighter than traditional designs.
  • Groove couplings facilitate ease of installation and pipeline alignment.
  • Features patented torsion spring checks for lowest pressure loss.
  • Designed for unmatched ease of serviceability.
  • Includes a bottom mounted cast stainless steel relief valve.

Shutoff Valves

  • Equipped with non-rising stem (NRS) resilient seated gate valves.

Use of the flood sensor does not replace the need to comply with all required instructions, codes, and regulations related to installation, operation, and maintenance of this product, including the need to provide proper drainage in the event of a discharge.

Specifications

General

  • Product Type: Reduced Pressure Zone (RPZ) Assembly
  • Connection Size: 4 inch
  • Shutoff Valve Type: Non-Rising Stem (NRS) Gate Valves
  • Installation: Horizontal
  • Wetted Surface Lead Content: Less than 0.25% (Lead Free*)

Materials

  • Housing & Sleeve Material: 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
  • Relief Valve: Cast Stainless Steel

Performance

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

Certificates & Approvals

  • Lead Free*
  • Approved by: Foundation for Cross-Connection Control and Hydraulic Research at USC (FCCCHR-USC)
  • Standard: AWWA C511-97
  • Standard: ASSE 1013
  • Standard: CSA B64.4
  • Certification: UL Classified
  • Certification: FM Approved
  • Certification: NSF Certified to NSF/ANSI 61-G

FAQs

What is the primary purpose of the Watts Series 957 Reduced Pressure Zone Assembly?

Its primary purpose is to protect potable water systems from contamination by preventing the reverse flow of liquids, specifically in health hazard applications where backpressure or backsiphonage could occur.

How does the flood sensor feature work and what is needed to activate it?

The flood sensor with SentryPlus Alert technology detects continuous discharge from the relief valve. To activate its alerting capabilities, an add-on sensor connection kit is required.

What communication options are available for the flood sensor alerts?

With an add-on connection kit, the sensor can integrate with Building Management Systems (BMS), cellular networks, or the Sensor Control Monitor for BAS via RS-485 Modbus or the Nexa platform via Wi-Fi.

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

The housing and sleeve are made from 304 (Schedule 40) stainless steel. Elastomers include EPDM, silicone, and Buna-N, while test cocks feature a Lead Free* bronze body.

What are the maximum operating pressure and temperature limits for this assembly?

This backflow preventer has a maximum working pressure of 175 psi (12.1 bar) and can operate within a temperature range of 33°F to 140°F (0.5°C to 60°C).

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