The Watts LF709-OSY NYC 4 inch Lead Free Double Check Valve Backflow Preventer Assembly prevents contaminated non-potable water from entering the potable water supply. Designed for non-health hazard cross-connections and service lines, it features a fused epoxy coated cast iron body and Outside Stem and Yoke (OSY) gate valves. The assembly utilizes ArmorTek® coating technology for superior corrosion resistance and includes pre-drilled 304SS bolts specifically for NYC tagging requirements. It has a maximum working pressure of 175 psi and is approved for vertical flow up installations. Its modular design allows for simplified maintenance.
The Watts LF709-OSY NYC 4 inch Lead Free Double Check Valve Backflow Preventer Assembly is designed to prevent the reverse flow of contaminated non-potable water into the potable water supply due to backsiphonage and/or backpressure. It is ideal for protection at cross-connections in non-health hazard applications.
This assembly comes with Outside Stem and Yoke (OSY) resilient seated gate valves and specific pre-drilled bolts for NYC tagging requirements.
Construction & Technology
Features a fused epoxy coated cast iron body for durability and corrosion resistance.
Includes a modular check design with a center stem guide for easy maintenance.
Equipped with test cocks for monitoring and inspection.
Utilizes ArmorTek® coating technology, a patented 3-part advanced epoxy system, designed to limit microbial induced (MIC) and exposed metal substrate corrosion.
The captured spring is accessible through a bolted cover plate for safety and simplified servicing.
Pre-drilled bolts: Four sets of 304SS bolts/nuts with a 1/4 inch hole drilled axially through each bolt, specifically for properly tagging backflow preventers as required in NYC.
Features
Modular design concept facilitates complete maintenance and allows assembly to retain spring load.
Replaceable resilient seats for extended service life.
Achieves maximum flow at low pressure drop.
No special tools required for servicing the assembly.
Approved for vertical flow up installation (for 4 inch to 10 inch sizes).
Valve Type: Outside Stem and Yoke (OSY) Gate Valves
Lead Free: Yes
Materials
Body Material: Epoxy coated cast iron
Coating: ArmorTek® powder coating (internal and external)
Seats: Stainless steel
Bolts/Nuts: 304SS (with 1/4 inch drilled hole)
Performance
Maximum Working Pressure: 175 psi (12.1 bar)
Temperature Range (Continuous): 33°F - 110°F (0.5°C - 43°C)
Temperature Range (Intermittent): 140°F (60°C)
Dimensions
Length (A): 52 3/8 inches (1332 mm)
OSY Length (C): 22 3/4 inches (578 mm)
Flange Diameter (D): 4 1/2 inches (114 mm)
Height (L): 34 1/8 inches (867 mm)
Approximate OSY Weight: 383 lbs (174 kg)
Certificates & Approvals
AWWA C510-92
IAPMO PA 31
USC Manual for Cross-Connection Control, 8th Edition
ASSE 1015
UPC Classified
cULus Listed
FM Approved (for 4" to 10" vertical "flow up" with OSY gate valves only)
NSF Certified to NSF/ANSI 61-G
CSA B64.5
Approved by Foundation for Cross-Connection Control and Hydraulic Research at University of Southern California
FAQs
What is the primary purpose of the Watts LF709-OSY NYC backflow preventer?
Its primary purpose is to prevent the reverse flow of non-potable, contaminated water into the potable water supply, protecting against backsiphonage and backpressure.
What makes this a "NYC version"?
This NYC version includes four sets of 304SS bolts/nuts with a 1/4 inch hole drilled axially through each bolt, specifically for properly tagging backflow preventers as required in New York City.
What is ArmorTek® coating technology?
ArmorTek® is a patented 3-part advanced epoxy coating system applied to the internal and external surfaces of the backflow preventer, designed to limit microbial induced (MIC) and exposed metal substrate corrosion.
What are the key materials used in this assembly?
The check valve body is made of epoxy coated cast iron, the seats are stainless steel, and the coating is ArmorTek® powder coating. It also features 304SS bolts/nuts.
What is the maximum operating pressure and temperature for this device?
The maximum working pressure for this backflow preventer is 175 psi. It operates continuously between 33°F and 110°F, and intermittently up to 140°F.
