4 LF957RPDA-DOSY-CFM-FS

Item Number: F792369
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$11,475.06
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Size: 4 inch
  • Weight: 243.0 lb
  • Lead Free* construction
  • Housing & Sleeve: 304 (Schedule 40) stainless steel
  • Maximum Operating Pressure: 175 psi
  • Temperature Range: 33°F - 110°F
  • Flood sensor with SentryPlus Alert® technology
  • UL Classified and FM Approved
  • Domestic OSY resilient seated gate valves

Description

This Watts Series LF957RPDA 4 inch lead free reduced pressure detector backflow preventer assembly protects potable water systems from contamination by backsiphonage or backpressure in health hazard applications. Its compact design features a 304 stainless steel housing, domestic OSY shutoff valves, and a bottom mounted cast stainless steel relief valve. An integrated flood sensor with SentryPlus Alert® technology detects continuous discharge, helping prevent costly damage. Approved by AWWA, ASSE, UL, FM, NSF, and FCCCHR-USC, it operates up to 175 psi from 33°F to 110°F, ensuring reliable performance and compliance.

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Flood Sensor Connectivity

The integrated flood sensor with SentryPlus Alert® technology provides advanced monitoring for continuous discharge from the relief valve. To activate its full alert capabilities, an add-on sensor connection kit is required.

  • When paired with a connection kit, the sensor can relay alerts for potential flooding events.
  • Connection kit options include compatibility with Building Management Systems (BMS) and cellular network communication.
  • Integration with a Sensor Control Monitor enables connectivity to BAS via RS-485 Modbus or the Nexa® platform through Wi-Fi.
  • Without an add-on connection kit, the sensor remains a passive component with no communication functionality.
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Additional Details

The Watts Series LF957RPDA 4 inch lead free reduced pressure detector backflow preventer assembly protects potable water systems from contamination due to backsiphonage and backpressure in health hazard applications, including fire protection systems.

This assembly incorporates a flood sensor to detect continuous discharge from the relief valve, monitoring unauthorized water use and helping to prevent costly damage from potential flooding events.

Features

  • Lead Free* construction meets national plumbing codes for reduced lead content.
  • Extremely compact design, up to 70% lighter than traditional backflow preventers.
  • 304 (Schedule 40) stainless steel housing and sleeve for durability.
  • Groove fittings allow for integral pipeline adjustment and ease of installation.
  • Patented torsion spring check valves provide the lowest pressure loss in its class.
  • Unmatched ease of serviceability with replaceable check disc rubber.
  • Features a bottom mounted cast stainless steel relief valve to reduce clearance requirements.
  • Includes a cubic feet per minute meter in the bypass assembly to detect underground leaks and unauthorized water use.
  • Equipped with a flood sensor with SentryPlus Alert® technology for continuous discharge detection.

An add-on sensor connection kit is required to activate the flood sensor. Without the connection kit, the sensor is a passive component that has no communication with any other device.

Specifications

  • Product Type: Reduced Pressure Detector Assembly
  • Size: 4 inch
  • Lead Content: Less than 0.25% by weight (wetted surfaces)
  • Housing & Sleeve Material: 304 (Schedule 40) stainless steel
  • Elastomer Material: 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
  • Shutoff Valves: Domestic OSY (Outside Stem and Yoke), Resilient Seated Gate Valves
  • Bypass Meter: Cubic Feet per Minute (CFM)
  • Relief Valve: Bottom Mounted Cast Stainless Steel
  • Flood Sensor Technology: SentryPlus Alert®
  • Installation Pattern: Horizontal

Performance

  • Maximum Working Pressure: 175 psi (12.1 bar)
  • Temperature Range: 33°F - 110°F (0.5°C - 43°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 1047
  • CSA B64.4
  • UL Classified
  • FM Approved
  • NSF Certified to NSF/ANSI 372

FAQs

What is the primary function of this 4-inch backflow preventer assembly?

This Watts LF957RPDA backflow preventer protects potable water systems from contamination caused by backsiphonage or backpressure, particularly in health hazard applications like fire protection systems.

What does "Lead Free" construction mean for this product?

"Lead Free" construction signifies that the wetted surfaces of this product, which come into contact with consumable water, contain less than 0.25% lead by weight, complying with national plumbing codes.

What kind of flood detection capabilities does this assembly offer?

It features an integrated flood sensor with SentryPlus Alert® technology that detects continuous water discharge from the relief valve. With an optional add-on connection kit, it can relay alerts via BMS, cellular, or Wi-Fi to prevent flooding and damage.

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

The Watts LF957RPDA is designed to operate with a maximum working pressure of 175 psi (12.1 bar) and within a temperature range of 33°F to 110°F (0.5°C to 43°C).

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

The housing and sleeve are constructed from 304 (Schedule 40) stainless steel. Internal components include EPDM, silicone, and Buna 'N' elastomers, Noryl® and stainless steel torsion spring checks, and Lead Free* bronze test cocks.

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