2.5 957-OSY-FxG-FS

Item Number: F191637
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$7,470.74
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Assembly Size: 2 1/2 inch
  • Weight: 225.0 lb
  • Housing Material: 304 Stainless Steel
  • Shutoff Valves: UL and FM Approved OSY Gate
  • Inlet Connection: Flanged
  • Outlet Connection: Grooved
  • Features: Flood Sensor with SentryPlus Alert
  • Maximum Working Pressure: 175 PSI
  • Wetted Surface: Lead Free* (<0.25% lead)

Description

The WATTS 2 1/2 inch Series 957 Reduced Pressure Zone (RPZ) backflow preventer with UL and FM Approved OSY shutoff valves provides robust protection for potable water systems against backpressure and backsiphonage. Featuring a 304 stainless steel housing and sleeve, it includes a SentryPlus Alert flood sensor to detect excessive relief valve discharges. Its compact, lightweight design ensures easy installation with flanged inlet and grooved outlet connections. This lead-free* assembly is ASSE 1013, CSA B64.4, UL, FM, NSF/ANSI 61-G, AWWA C511-97, and FCCCHR-USC approved for health hazard applications. Item number F191637.

Help Me Connect

Connections and Installation

  • The inlet side of this assembly requires a flanged connection.
  • The outlet side of this assembly requires a grooved connection.
  • The assembly is approved for horizontal installation. Ensure it is installed in accordance with the direction of the flow arrow.

When installing a drain line for this backflow preventer, use 957AG air gaps. Attach the air gap brackets directly onto the flood sensor for proper function.

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Additional Details

This 2 1/2 inch Reduced Pressure Zone (RPZ) assembly backflow preventer provides protection to potable water systems from contamination in applications where backpressure or backsiphonage poses a health hazard. It features an extremely compact design and is lighter than traditional models, approved for horizontal installation when aligned with the flow arrow.

The assembly includes a 304 (Schedule 40) stainless steel housing and sleeve, torsion spring check valves, and a corrosive-resistant cast stainless steel bottom-mounted pressure relief valve.

Key Features

  • Equipped with a flood sensor with SentryPlus Alert technology to detect continuous discharge from the relief valve.
  • Features UL Classified and FM Approved outside stem and yoke (OSY) resilient seated gate valves.
  • Designed with patented torsion spring check modules for unmatched ease of serviceability and lowest pressure loss.
  • Groove fittings allow for integral pipeline adjustment and ease of installation.
  • Compact design permits use in smaller enclosures.

Flood Sensor Technology

  • The integrated flood sensor actively monitors for excessive water discharges from the relief valve.
  • Requires an add-on sensor connection kit (sold separately) to activate flood alert features, enabling compatibility with BMS, cellular communication, or integration with BAS via RS-485 Modbus or the Nexa platform through Wi-Fi connectivity.

Specifications

  • Assembly Size: 2 1/2 inch
  • Housing & Sleeve Material: 304 (Schedule 40) Stainless Steel
  • Elastomer Materials: EPDM, Silicone, Buna-N
  • Torsion Spring Check Material: Noryl®, Stainless Steel
  • Check Disc Material: Reversible Silicone or EPDM
  • Test Cock Material: Lead Free* Bronze Body
  • Pins & Fastener Material: 300 Series Stainless Steel
  • Spring Material: Stainless Steel

Pressure & Temperature

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

Connections

  • Inlet Shutoff Valve: Flanged OSY Gate Valve
  • Outlet Shutoff Valve: Grooved OSY Gate Valve

Certificates & Approvals

  • ASSE 1013
  • CSA B64.4
  • UL Classified
  • FM Approved
  • NSF/ANSI 61-G
  • AWWA C511-97
  • FCCCHR-USC Approved

FAQs

What is the primary purpose of the WATTS 957-OSY-FxG-FS backflow preventer?

This 2 1/2 inch Reduced Pressure Zone (RPZ) assembly is designed to protect potable water systems from contamination caused by backpressure or backsiphonage, especially in health hazard applications.

How does the flood sensor feature operate?

The integrated flood sensor with SentryPlus Alert technology detects continuous water discharge from the relief valve. To activate its alerting capabilities, an add-on sensor connection kit (sold separately) is required, which enables communication with BMS, cellular networks, or the Nexa platform.

What are the connection types for this specific model?

This model, designated FxG, features a flanged connection for the inlet gate valve and a grooved connection for the outlet gate valve. The groove fittings facilitate pipeline adjustment during installation.

What materials are used for the main components of this backflow preventer?

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

Is this backflow preventer certified for potable water applications?

Yes, it is "Lead Free*" with wetted surfaces containing less than 0.25% lead, and is NSF/ANSI 61-G certified. It also holds approvals from ASSE 1013, CSA B64.4, UL, FM, AWWA C511-97, and FCCCHR-USC.

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