The Watts Series LF757DCDA is an 8 inch Lead Free Double Check Detector Backflow Preventer Assembly designed to protect potable water systems from non-health hazard pollutants. Primarily installed on fire line sprinkler systems, it also monitors unauthorized water usage with an integrated gallons per minute meter. This assembly features a compact, 70% lighter design with a 304 stainless steel housing, OSY gate shutoff valves, and groove end connections. It can withstand a maximum working pressure of 175 PSI and operates within a temperature range of 33°F to 140°F. Approvals include AWWA C510-97, ASSE 1048, CSA B64.5, UL, FM, and NSF/ANSI 372.
Help Me Connect
Connections
This double check detector assembly features groove end connections for easy and integral pipeline adjustment.
Equipped with OSY (Outside Stem and Yoke) gate shutoff valves on both the inlet and outlet.
The unit can be installed in horizontal, vertical, or N pattern orientations.
The Watts Series LF757DCDA 8 inch Lead Free Double Check Detector Assembly prevents backflow of non-health hazard pollutants from entering potable water supply systems. This assembly is primarily used on fire line sprinkler systems when it is necessary to monitor unauthorized water usage.
Features
Lead Free* construction ensuring less than 0.25% lead by weight in wetted surfaces.
Extremely compact design, approximately 70% lighter than traditional models.
Housing and sleeve constructed from 304 (Schedule 40) stainless steel.
Groove fittings allow for integral pipeline adjustment.
Unique tri-link spring check provides the lowest pressure loss.
Unmatched ease of serviceability with removable and serviceable checks without special tools.
Equipped with OSY (Outside Stem and Yoke) gate shutoff valves.
May be used for horizontal, vertical, or N pattern installations.
Features replaceable check disc rubber.
Construction & Operation
Consists of two independent tri-link check modules within a single housing, sleeve access port, four test cocks, and two drip-tight shutoff valves.
The housing is constructed of 304 Schedule 40 stainless steel pipe with groove end connections.
The bypass assembly includes a meter which registers in gallons or cubic measurement, a double check backflow assembly, and required test cocks for monitoring water usage.
Specifications
Product Type: Double Check Detector Assembly
Model Series: LF757DCDA
Nominal Size: 8 inch
Shutoff Valves: OSY (Outside Stem and Yoke) Gate Valves
Pins & Fastener Material: 300 Series Stainless Steel
Spring Material: Stainless Steel
Performance
Temperature Range: 33°F - 140°F (0.5°C - 60°C)
Maximum Working Pressure: 175 PSI (12.1 bar)
Certificates & Approvals
Approved by: Foundation for Cross-Connection Control and Hydraulic Research (FCCCHR-USC)
AWWA: C510-97
ASSE: 1048
CSA: B64.5
Classified by: UL
Approved by: FM (for OSY and BFG models)
Certified to: NSF/ANSI 372
FAQs
What is the primary purpose of the Watts LF757DCDA 8 inch Double Check Detector Assembly?
This assembly is designed to prevent the backflow of non-health hazard pollutants, such as those found in fire line sprinkler systems, from entering the potable water supply. It also includes a meter to monitor unauthorized water usage.
What does "Lead Free" construction mean for this backflow preventer?
The "Lead Free" construction indicates that the wetted surface of the product, which comes into contact with consumable water, contains less than 0.25% of lead by weight, meeting industry standards for potable water safety.
What are the main materials used in the construction of this assembly?
The housing and sleeve are constructed from 304 Schedule 40 stainless steel. Other components include EPDM, Silicone, and Buna-N elastomers, Noryl® and stainless steel for tri-link checks, and Lead Free* bronze for test cock bodies.
What are the pressure and temperature limitations of the LF757DCDA?
This assembly has a maximum working pressure of 175 PSI (12.1 bar). It is designed to operate within a temperature range of 33°F to 140°F (0.5°C to 60°C).
What type of shutoff valves are included with this backflow preventer?
This model, the LF757DCDA-OSY, is equipped with UL/FM approved OSY (Outside Stem and Yoke) resilient seated gate valves.
