2 1/2 957-DOSY

Item Number: 0113040
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$8,445.17
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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 & Sleeve: 304 Stainless Steel
  • Shutoff Valves: Domestic OSY Resilient Seated Gate Valves
  • Maximum Operating Pressure: 175 PSI
  • Temperature Range: 33°F - 140°F
  • Features: Flood Sensor for Discharge Detection
  • Design: Extremely Compact, Lighter Weight
  • Certifications: ASSE 1013, CSA B64.4, CULUS, FM, NSF/ANSI 61-G, AWWA C511-97

Description

The Watts 2 1/2 inch 957-DOSY Reduced Pressure Zone Assembly Backflow Preventer protects potable water systems from contamination by preventing reverse flow from backsiphonage or backpressure. This lead-free, compact assembly features a durable 304 stainless steel housing, OSY shutoff valves, and a bottom-mounted relief valve with an integrated flood sensor. Rated for 175 PSI and temperatures from 33°F to 140°F, it's suitable for health hazard applications and horizontal installation. It meets ASSE 1013, CSA B64.4, UL, FM, NSF/ANSI 61-G, and AWWA C511-97 standards.

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Installation & Connections

  • This assembly is approved for horizontal installation, provided it is installed in accordance with the direction of the flow arrow.
  • Features groove couplings for ease of installation and integral pipeline adjustment.
  • Equipped with domestic outside stem and yoke (OSY) resilient seated gate valves.
  • An add-on connection kit is required to activate the flood sensor for communication with other devices.
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Additional Details

This 2 1/2 inch reduced pressure zone assembly backflow preventer is designed to help prevent the reverse flow of fire protection substances and non-potable water into the potable water supply, protecting against both backsiphonage and backpressure in health hazard applications, in accordance with national plumbing codes.

This extremely compact and lighter-than-traditional design is approved for horizontal installation when installed in accordance with the direction of the flow arrow.

Construction & Features

  • Features a 304 stainless steel housing and sleeve with a quick access sleeve.
  • Includes patented torsion spring check modules for lowest pressure loss and ease of serviceability.
  • Equipped with domestic outside stem and yoke (OSY) resilient seated gate valves.
  • Incorporates a bottom-mounted cast stainless steel relief valve.
  • A flood sensor is included to detect excessive water discharges from the relief valve, providing notification for corrective action.
  • Groove couplings allow for integral pipeline adjustment and ease of installation.
  • Designed for continuous pressure piping applications.

Specifications

  • Assembly Size: 2 1/2 inch
  • Housing & Sleeve Material: 304 (Schedule 40) stainless steel
  • Shutoff Valves: Domestic Outside Stem and Yoke (OSY) Resilient Seated Gate Valves
  • Elastomers: 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
  • Maximum Working Pressure: 175 psi (12.1 bar)
  • Temperature Range: 33°F - 140°F (0.5°C - 60°C)
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
  • CULUS Classified (BFG & OSY Only)
  • FM Approved (BFG & OSY Only)
  • NSF Certified to NSF/ANSI 61-G

FAQs

What is the primary purpose of this backflow preventer?

The Watts 2 1/2 inch 957-DOSY Reduced Pressure Zone Assembly Backflow Preventer is designed to protect potable water systems from contamination due to backsiphonage and backpressure from non-potable sources, especially in health hazard applications.

What materials are used in the construction of this assembly?

The housing and sleeve are made from 304 (Schedule 40) stainless steel. Elastomers include EPDM, silicone, and Buna-N. Test cocks are made from Lead Free* bronze, and other components like pins, fasteners, and springs are stainless steel.

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

This assembly has a maximum working pressure of 175 psi (12.1 bar) and an operating temperature range of 33°F to 140°F (0.5°C to 60°C).

Is this assembly approved for horizontal installation?

Yes, this backflow preventer is approved for horizontal installation, provided it is installed strictly in accordance with the direction of the flow arrow and all relevant codes and instructions.

What is the function of the flood sensor?

The flood sensor detects excessive water discharges from the relief valve. When paired with an add-on connection kit, it can relay a signal to facility personnel for corrective action, helping to limit flooding and potential damage.

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