4 957-NRS-S-FS

Item Number: F111827
1 1
$8,355.00
Special Order
When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Size: 4 inch
  • Weight: 399.0 lb
  • Valve Type: Non-Rising Stem (NRS) Gate Valves
  • Housing Material: 304 Stainless Steel
  • Integrated Flood Sensor: SentryPlus Alert® Technology
  • Maximum Working Pressure: 175 psi
  • Temperature Range: 33°F - 140°F
  • Lead Free Wetted Surface
  • Includes Cast Iron Flanged Strainer

Description

The Watts Series 957 4 inch Reduced Pressure Zone (RPZ) backflow preventer with non-rising stem (NRS) gate valves safeguards potable water systems from contamination due to backpressure and backsiphonage. This compact unit features a durable 304 stainless steel housing, a cast iron flanged strainer, and an integrated SentryPlus Alert® flood sensor for detecting excessive water discharge. Designed for health hazard applications, it includes replaceable check disc rubber and offers unmatched serviceability. The lead-free wetted surfaces ensure water quality. Ideal for horizontal installations, this ASSE 1013 and CSA B64.4 approved assembly provides reliable protection for commercial and industrial settings.

Help Me Connect

Installation Notes

  • This assembly is approved for horizontal installation, provided it is installed in accordance with the direction of the flow arrow.
  • To activate the flood sensor's alert features, an optional add-on sensor connection kit is required. Without this kit, the sensor operates as a passive component with no external communication.
  • For drain line installations, use 957AG air gaps and attach the air gap brackets directly onto the flood sensor.

Flood Sensor Compatibility

The flood sensor's alert capabilities are compatible with various communication options through add-on connection kits, including Building Management Systems (BMS), cellular communication, and the Sensor Control Monitor for integration with BAS via RS-485 Modbus or the Nexa® platform via Wi-Fi.

View full details

Additional Details

The Watts Series 957 Reduced Pressure Zone assembly is a 4 inch backflow preventer designed to protect potable water systems from contamination caused by backpressure or backsiphonage in health hazard applications. This assembly features a compact design, a 304 (Schedule 40) stainless steel housing and sleeve, and non-rising stem (NRS) resilient seated gate valves.

A key component of this unit is the integrated flood sensor with SentryPlus Alert® technology, which detects excessive water discharge from the relief valve. When paired with an add-on connection kit (sold separately), the sensor activates to relay alerts, helping to prevent potential flooding and costly damage. The assembly also includes a cast iron flanged strainer for comprehensive system protection.

Features

  • Provides protection against backsiphonage and backpressure in health hazard applications.
  • Includes an integrated flood sensor with SentryPlus Alert® technology for detecting excessive water discharge.
  • Flood alerts activated with an optional add-on sensor connection kit (compatible with BMS, cellular communication, and Nexa® platform).
  • 304 (Schedule 40) stainless steel housing and sleeve for durability.
  • Non-rising stem (NRS) resilient seated gate valves.
  • Replaceable check disc rubber for easy maintenance.
  • Extremely compact design, up to 70% lighter than traditional models.
  • Groove fittings allow for integral pipeline adjustment and ease of installation.
  • Patented torsion spring checks provide lowest pressure loss.
  • Bottom mounted cast stainless steel relief valve.
  • Equipped with a cast iron flanged strainer.
  • Quick access sleeve for unmatched ease of serviceability.

Specifications

  • Nominal Pipe Size: 4 inch
  • Valve Type: Non-Rising Stem (NRS) Resilient Seated Gate Valves
  • Housing & Sleeve Material: 304 (Schedule 40) Stainless Steel
  • Strainer Material: Cast Iron
  • Relief Valve Material: Cast Stainless Steel
  • Test Cocks Material: Lead Free* Bronze Body
  • Pins & Fasteners Material: 300 Series Stainless Steel
  • Springs Material: Stainless Steel
  • Elastomers: EPDM, Silicone, Buna-N
  • Check Discs: Reversible Silicone or EPDM
  • Torsion Spring Checks: Noryl®, Stainless Steel
  • Maximum Working Pressure: 175 psi (12.1 bar)
  • Temperature Range: 33°F - 140°F (0.5°C - 60°C)
  • Wetted Surface Lead Content: Less than 0.25% by weight

Certificates & Approvals

  • ASSE 1013
  • CSA B64.4
  • NSF/ANSI 61-G
  • AWWA C511-97
  • Foundation for Cross-Connection Control and Hydraulic Research (FCCCHR-USC) Approved

FAQs

What is the primary function of the Watts Series 957 backflow preventer?

Its primary function is to protect potable water systems from contamination that can occur due to backpressure or backsiphonage, particularly in health hazard applications.

Does this backflow preventer come with an active flood sensor?

It includes an integrated flood sensor with SentryPlus Alert® technology. To activate its alert features and enable communication, an optional add-on connection kit must be purchased separately.

What type of shutoff valves does this 4-inch model use?

This 4-inch model is equipped with non-rising stem (NRS) resilient seated gate valves, which are designed for reliable shutoff and isolation.

What material is the housing and sleeve made from?

The housing and sleeve are constructed from durable 304 (Schedule 40) stainless steel, offering excellent corrosion resistance and longevity.

Is this Watts Series 957 assembly approved for horizontal installation?

Yes, this backflow preventer is approved for horizontal installation, provided that the assembly is installed according to the direction of the flow arrow.

Related Products

1 4