2 1/2 LF909-DOSY-FS

Item Number: 88009328
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$14,732.61
Limited Stock (3)
Estimated transit time: 2 to 5 Business Days Eligible for Express Shipping

Brand - Watts
  • Size: 2 1/2 inch
  • Weight: 198.0 lb
  • Body Material: Cast Iron with ArmorTek® Coating
  • Shutoff Valves: Domestic OSY Gate Valves
  • Pressure Rating: 175 psi Maximum
  • Lead Free: Yes, compliant construction
  • Flood Sensor: Integrated with SentryPlus Alert® technology
  • Relief Valve Design: Air-in/water-out for high capacity discharge
  • Certifications: ASSE 1013, AWWA C511-92, CSA B64.4, UL, FM, NSF/ANSI 61-G

Description

The 2 1/2 inch Watts LF909 Reduced Pressure Zone Backflow Preventer Assembly provides critical protection against backflow and backsiphonage in potable water systems. Featuring a durable cast iron body with advanced ArmorTek® epoxy coating, this assembly is designed to resist corrosion, including microbial-induced corrosion. It includes domestic OSY shutoff valves and a unique air-in/water-out relief valve for high-capacity discharge during emergencies. An integrated SentryPlus Alert® flood sensor detects excessive water discharge, offering enhanced system monitoring when paired with an add-on connection kit. This Lead Free assembly is certified to ASSE 1013, AWWA C511-92, CSA B64.4, UL, FM, and NSF/ANSI 61-G standards.

Help Me Connect

The Watts Series LF909 Backflow Preventer is equipped with domestic outside stem and yoke (OSY) shutoff valves for reliable operation. For effective flood monitoring, an add-on sensor connection kit (sold separately) is required to activate the integrated flood sensor's alert features.

Sensor Connectivity

  • The flood sensor is compatible with Building Management Systems (BMS) and cellular networks.
  • It can also integrate with a Sensor Control Monitor for advanced functionality, allowing connection to BAS via RS-485 Modbus or the Nexa® platform through Wi-Fi connectivity.

Installation Notes

  • When installing a drain line on horizontally mounted Series 909 backflow preventers, Series 909 AG air gaps should be used to ensure proper drainage and an adequate air gap.
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Additional Details

The 2 1/2 inch Watts Series LF909 Reduced Pressure Zone Backflow Preventer Assembly is designed to prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage and backpressure. It is ideal for protection in continuous pressure piping applications and at cross-connections identified as health hazards.

This assembly consists of an epoxy coated cast iron body, domestic outside stem and yoke (OSY) resilient seated gate valves, captured spring check valves, replaceable seats, top mounted test cocks, and a field reversible pressure differential relief valve.

Corrosion Protection

  • Features ArmorTek® coating technology, a patented three-part advanced epoxy system, applied to internal and external surfaces.
  • Engineered to reduce microbial-induced corrosion (MIC) and protect exposed metal substrates.
  • Lead Free* construction complies with current installation requirements.

Flood Detection & Alerts

  • Includes a flood sensor with SentryPlus Alert® technology to detect excessive water discharges from the relief valve.
  • An add-on connection kit (required, sold separately) is necessary to activate the sensor's alert features for facility personnel.
  • Allows for integration with Building Management Systems (BMS), cellular communication, or the Nexa® platform via Wi-Fi connectivity and RS-485 Modbus.

Performance Features

  • Unique patented air-in and water-out relief valve design provides maximum capacity during emergency conditions.
  • Replaceable seats and stainless steel internal parts ensure durability and ease of servicing.

Specifications

General

  • Product Type: Reduced Pressure Zone Backflow Preventer
  • Series: LF909
  • Nominal Size: 2 1/2 inch
  • Body Material: Cast Iron
  • Coating: ArmorTek® Powder Coating (internal and external surfaces)
  • Relief Valve Body Material: Lead Free* Cast Copper Silicon Alloy
  • Seat Material: Stainless Steel
  • Trim Material: Stainless Steel
  • Test Cock Material: Lead Free* Copper Silicon Alloy
  • Shutoff Valves: Domestic Outside Stem and Yoke (OSY) Resilient Seated Gate Valves
  • Lead Free: Yes (wetted surface contains less than 0.25% lead by weight)

Pressure & Temperature

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

Flood Sensor

  • Flood Sensor Type: SentryPlus Alert® Technology
  • Sensor Functionality: Detects excessive water discharges from relief valve
  • Activation Requirement: Add-on connection kit (sold separately)
  • Communication Compatibility: BMS, cellular network, Sensor Control Monitor (BAS via RS-485 Modbus, Nexa® platform via Wi-Fi)

Certificates & Approvals

  • ASSE: 1013
  • AWWA: C511-92
  • CSA: B64.4
  • IAPMO: PS 31 (UPC Listed)
  • SBCCI: (Standard Plumbing Code)
  • UL: Classified File No. EX3185
  • FM: Approved
  • 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 function of the Watts LF909 backflow preventer?

This assembly is designed to prevent the reverse flow of polluted water into the potable water supply due to both backsiphonage and backpressure, making it suitable for health hazard cross-connections.

What type of shutoff valves are included with this assembly?

The Watts LF909-DOSY-FS assembly comes equipped with domestic outside stem and yoke (OSY) resilient seated gate valves.

How does the ArmorTek® coating benefit this backflow preventer?

The patented ArmorTek® three-part advanced epoxy coating system is applied to both internal and external surfaces to reduce microbial-induced corrosion (MIC) and protect exposed metal substrates, extending the life of the unit.

Does this backflow preventer have flood detection capabilities?

Yes, it includes an integrated flood sensor with SentryPlus Alert® technology to detect excessive water discharges from the relief valve. An add-on connection kit is required to activate its alert features.

What is the maximum operating pressure and temperature for this model?

This 2 1/2 inch LF909 assembly has a maximum working pressure of 175 psi (12.06 bar) and operates continuously in temperatures from 33°F to 110°F (0.5°C to 43°C).

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