4 LF909-DOSY-FS

Item Number: 88009310
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$20,941.13
Limited Stock (1)
Estimated transit time: 2 to 5 Business Days Eligible for Express Shipping

Brand - Watts
  • Size: 4 inch
  • Weight: 640.0 lb
  • Product Type: Reduced Pressure Zone Backflow Preventer
  • Shutoff Valves: Domestic OSY
  • Body Material: Cast Iron with ArmorTek® Coating
  • Maximum Working Pressure: 175 psi
  • Lead Free: Yes
  • Flood Sensor: Included with SentryPlus Alert® technology
  • Temperature Range: 33°F to 110°F continuous

Description

The Watts 4 inch LF909 Reduced Pressure Zone Backflow Preventer Assembly is engineered for cross-connection control in potable water supplies. It prevents backflow from backsiphonage or backpressure in continuous pressure piping, ideal for health hazard protection. Featuring an ArmorTek® coated cast iron body, domestic OSY shutoff valves, and stainless steel internals, it ensures durability. A built-in flood sensor with SentryPlus Alert® technology detects excessive relief valve discharge, offering proactive monitoring. With a maximum working pressure of 175 psi and Lead Free* construction, this assembly meets strict industry standards for safety and performance.

Help Me Connect

Flood Sensor Connectivity

The integrated flood sensor is designed to detect excessive water discharges from the relief valve. To activate its full alert capabilities, an add-on sensor connection kit is required. Without this kit, the sensor operates as a passive component with no external communication.

  • Connection Kit Options: Available kits can enable compatibility with Building Management Systems (BMS), cellular communication, or the Sensor Control Monitor.
  • Integration: The Sensor Control Monitor facilitates integration with Building Automation Systems (BAS) via RS-485 Modbus or the Nexa® platform through Wi-Fi connectivity.

Drain Line Installation

The installation of a drain line is recommended for proper discharge in the event of a relief valve discharge. When installing a drain line, ensure an air gap is maintained.

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Additional Details

The 4 inch Watts Series LF909 Reduced Pressure Zone Backflow Preventer Assembly is designed to prevent the reverse flow of polluted water into the potable water supply due to backsiphonage or backpressure. It is ideal for continuous pressure piping applications and protecting against health hazards at cross-connections.

This assembly features a durable cast iron body with ArmorTek® coating, domestic outside stem and yoke (OSY) resilient seated gate valves, and a flood sensor with SentryPlus Alert® technology for enhanced monitoring.

Construction & Design

  • Features an epoxy coated cast iron body and captured spring check valves.
  • Incorporates replaceable seats and a field reversible pressure differential relief valve for easy maintenance.
  • ArmorTek®, a patented 3-part advanced epoxy coating system, limits microbial induced corrosion (MIC) and protects exposed metal substrates.
  • Utilizes a unique air-in/water-out relief valve design for maximum discharge capacity during emergency conditions.
  • Constructed with Lead Free* materials for compliance with installation requirements.

Flood Detection & Alerts

  • A built-in flood sensor detects excessive water discharges from the relief valve.
  • SentryPlus Alert® technology relays signals for facility personnel notification, helping to limit flooding and costly damage.
  • When paired with an add-on sensor connection kit (sold separately), flood alerts can be activated.
  • Compatible with BMS, cellular communication, or the Sensor Control Monitor for integration with BAS via RS-485 Modbus or the Nexa® platform by Wi-Fi connectivity.

Specifications

General

  • Product Type: Reduced Pressure Zone Backflow Preventer Assembly
  • Size: 4 inch
  • Model: LF909
  • Shutoff Valves: Domestic Outside Stem and Yoke (OSY)
  • Flood Sensor: Yes, with SentryPlus Alert® technology
  • Lead Free: Yes (wetted surface contains less than 0.25% lead by weight)

Materials

  • Check Valve Body Material: Cast Iron
  • Check Valve Body Coating: ArmorTek® powder coating (internal and external surfaces)
  • Relief Valve Body Material: Cast Iron
  • Seat Material: Stainless Steel
  • Trim Material: Stainless Steel
  • Test Cock Material: Lead Free* copper silicon alloy

Performance

  • Maximum Working Pressure: 175 psi (12.06 bar)
  • Continuous Temperature Range: 33°F to 110°F (0.5°C to 43°C)
  • Intermittent Temperature Range: 140°F (60°C)

Certificates & Approvals

  • ASSE 1013
  • AWWA C511-92
  • CSA B64.5
  • UL Classified File No. EX3185
  • IAPMO (UPC)
  • SBCCI (Standard Plumbing Code)
  • USC Manual for Cross-Connection Control, 8th Edition
  • NSF Certified to NSF/ANSI 61-G
  • Approved by the Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California

FAQs

What is the primary purpose of the Watts LF909 Reduced Pressure Zone Backflow Preventer?

Its primary purpose is to prevent the reverse flow of polluted water into the potable water supply due to backsiphonage or backpressure, protecting against health hazards in cross-connections.

What kind of coating is used on the cast iron body and what are its benefits?

The cast iron body is coated with ArmorTek®, a patented three-part advanced epoxy system. This coating is engineered to reduce microbial-induced corrosion (MIC) and protect exposed metal substrates.

Does this backflow preventer come with shutoff valves?

Yes, this assembly includes domestic Outside Stem and Yoke (OSY) resilient seated gate valves as shutoff valves.

What is the function of the flood sensor included with the LF909 assembly?

The flood sensor with SentryPlus Alert® technology detects excessive water discharges from the relief valve. When connected with an add-on kit, it can relay alerts to facility personnel for corrective action.

Is this product suitable for high-pressure applications?

Yes, the Watts LF909 Reduced Pressure Zone Backflow Preventer Assembly has a maximum working pressure of 175 psi (12.06 bar), making it suitable for continuous pressure piping applications.

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