The Watts 774DCDA-OSY-LM 3 is a 3" double check detector assembly (DCDA) with Flanged connections, approved for low health hazard protection. It features a stainless body. Rated to 175 psi and 33°F to 110°F.
This 3" double check detector backflow preventer assembly prevents the backflow of fire protection system substances from being pumped or siphoned into the potable water supply. It consists of a compact construction and short lay length, ideal for retrofit installations. It features a lightweight stainless steel body, thermoplastic and stainless steel check valves, and low head loss. It has outside stem and yoke shutoffs. It can be installed in a horizontal or vertical flow-up position. It is designed for installation on applications identified by local authorities as non-health hazard, such as on fire protection systems. The maximum working pressure is 175 psi (12.06 bar).
Features
- Stainless steel for corrosion resistance
- Designed for minimum head loss
- 150 pound ANSI/AWWA CL D flanged
- Outside screw and yoke shutoffs
Common Questions
- What hazard level is this DCDA approved for?
- It is rated for low health hazard (non-toxic, "pollutant") cross-connections only. Where the substance downstream could be a health hazard, codes require a reduced pressure zone (RPZ) assembly instead. The assembly is listed to ASSE 1048.
- Can this be installed on potable water?
- No. This model is not certified lead-free, so it may not be installed in potable water systems in states enforcing the NSF/ANSI 372 weighted-average lead rule. Use it on non-potable service — fire lines, irrigation or industrial water — or order the LF (lead-free) version of this model for drinking-water use.
- Does this assembly have to be tested every year?
- Yes. This is a field-testable assembly. Most water authorities require it to be tested and certified by a licensed backflow tester at installation and annually thereafter.
- What shutoff valves are included?
- It is supplied with outside screw and yoke (OS&Y) gate valves on the inlet and outlet. OS&Y gates give the visible open/shut indication that fire-line and many water-authority specs require.
- Is this suitable for a fire sprinkler line?
- Yes. Detector assemblies are built for fire sprinkler service: the metered bypass registers the low flows that reveal a leak or an unauthorized tap on the fire line. This model is UL Classified and FM Approved. This is the "less meter" (LM) variant — the bypass line is supplied without the meter, which you specify separately.
- How does this have to be installed?
- It is approved for either horizontal or vertical installation, with the flow arrow on the body pointing in the direction of flow.
Specifications
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Type: Double Check
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Size: 3"
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Inlet Size: 3"
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Outlet Size: 3"
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Connection: Flanged
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Body Material: Stainless
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Max Pressure (psi): 175
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Application: Fire Protection
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Backflow Protection: Backpressure
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Operation: Continuous
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Country of Origin: United States
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Warranty: 1 Year Limited
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MPN: 774DCDA-OSY-LM 3
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Temperature: 33°F to 110°F
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Certifications: CSA-B64, UL, FM
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Lead-Free: No
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Assembly Type: DCDA
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Hazard Protection Level: Low Health Hazard
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ASSE Standard: ASSE 1048
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USC FCCCHR Approved: No
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Fire Protection Listing: UL Classified;FM Approved
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Field Testable: Yes
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Shutoff Valves: OSY Gate
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Approved Orientation: Horizontal & Vertical
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Flood Sensor (SentryPlus Alert): No
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Strainer Included: No
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Air Gap Fitting Included: No
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Bypass Meter: None
