2.5 957Z-OSY-FS

Item Number: F111596
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$10,044.89
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Nominal Size: 2 1/2 inch
  • Weight: 186.0 lb
  • Pattern: Z-Pattern Orientation
  • Shutoff Valves: Outside Stem and Yoke (OSY)
  • Flood Sensor: SentryPlus Alert® technology
  • Housing & Sleeve: 304 (Schedule 40) Stainless Steel
  • Maximum Working Pressure: 175 PSI
  • Temperature Range: 33°F - 140°F
  • Certified: CSA B64.4, AWWA C511-97, ASSE 1013, cULus, FM, NSF/ANSI 61-G

Description

The Watts Series 957 Reduced Pressure Zone (RPZ) Assembly Backflow Preventer, 2 1/2 inch, Z-Pattern, OSY, protects potable water systems from contamination by preventing backpressure and backsiphonage in health hazard applications. This compact, lead-free assembly features a durable 304 stainless steel housing and OSY resilient seated gate valves. It includes an integrated flood sensor with SentryPlus Alert® technology to detect excessive discharge, which can be activated with an optional connection kit for BMS, cellular, or Wi-Fi alerts. Rated for 175 PSI and temperatures from 33°F to 140°F, it is approved by ASSE 1013, CSA B64.4, cULus, FM, and NSF/ANSI 61-G.

Help Me Connect

Installation Orientation

  • This assembly is approved for horizontal Z-pattern installation. Ensure the backflow assembly is installed in accordance with the direction of the flow arrow.

Pipeline Connection

  • Features groove couplings for ease of installation and precise pipe alignment with compatible grooved piping systems.

Flood Sensor Connectivity

  • The integrated flood sensor requires an add-on connection kit to activate its communication features.
  • Connection kit options allow integration with Building Management Systems (BMS), cellular communication networks, or the Sensor Control Monitor for advanced alert capabilities via RS-485 Modbus or the Nexa® platform by Wi-Fi.
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Additional Details

This 2 1/2 inch Reduced Pressure Zone (RPZ) Assembly Backflow Preventer provides critical protection to potable water systems by preventing the reverse flow of liquids due to backpressure or backsiphonage, particularly in health hazard applications. Its Z-pattern orientation is suitable for horizontal installation.

The assembly is designed to be extremely compact and is 70% lighter than traditional designs, featuring a robust 304 (Schedule 40) stainless steel housing and sleeve.

Flood Detection & Alerts

  • Includes a flood sensor with SentryPlus Alert® technology to detect continuous discharge from the relief valve.
  • When activated with an add-on connection kit, the sensor relays signals to facility personnel for corrective action, helping to limit flooding and costly damage.
  • Connection kit options include BMS, cellular communication, and the Sensor Control Monitor for integration with BAS via RS-485 Modbus or the Nexa® platform through Wi-Fi.
  • An add-on connection kit is required to activate the flood sensor's communication features; without it, the sensor is a passive component.

Key Features

  • UL Classified and FM Approved Outside Stem and Yoke (OSY) resilient seated gate valves.
  • Replaceable check disc rubber for easy maintenance.
  • Bottom mounted cast stainless steel relief valve.
  • Groove couplings facilitate ease of installation and pipe alignment.
  • Patented torsion spring checks provide lowest pressure loss.
  • Unmatched ease of serviceability.

NOTICE: 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
  • Nominal Size: 2 1/2 inch
  • Pattern: Z-Pattern Orientation
  • Shutoff Valves: Outside Stem and Yoke (OSY)
  • Flood Sensor: Integrated with SentryPlus Alert® technology
  • Lead Free: Yes (wetted surface contains less than 0.25% lead by weight)

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 Body: Lead Free* Bronze
  • Pins & Fasteners: 300 Series Stainless Steel
  • Springs: Stainless Steel

Performance

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

Certificates & Approvals

  • Approved By: Foundation for Cross-Connection Control and Hydraulic Research (FCCCHR-USC)
  • Standard: AWWA C511-97
  • Standard: ASSE 1013
  • Standard: CSA B64.4
  • Classification: cULus Classified
  • Approval: FM Approved
  • Certification: NSF/ANSI 61-G

FAQs

What is the primary function of this backflow preventer?

This Reduced Pressure Zone (RPZ) assembly protects potable water systems from contamination by preventing the reverse flow of liquids due to backpressure or backsiphonage, especially in health hazard applications.

What is the significance of the Z-pattern orientation?

The Z-pattern orientation indicates that this assembly is designed for horizontal installation, with the flow direction matching the arrow on the unit.

How does the integrated flood sensor work?

The flood sensor with SentryPlus Alert® technology detects excessive water discharges from the relief valve. When paired with an add-on connection kit, it can relay signals and alerts to facility personnel or connected systems.

What materials are used for the main housing and internal components?

The housing and sleeve are constructed from 304 (Schedule 40) stainless steel. Key internal components like check discs and elastomers are made from replaceable silicone, EPDM, or Buna-N, while test cocks feature a Lead Free* bronze body.

Is this backflow preventer lead-free?

Yes, the wetted surface of this product that contacts consumable water contains less than 0.25% of lead by weight, meeting lead-free requirements.

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