The Watts 757DCDA-OSYXPIV-GPM 4 is a 4" double check detector assembly (DCDA), approved for low health hazard protection. It features a silicone seat. Rated to 175 psi and 33°F to 140°F.
This 4" stainless steel double check detector backflow preventer is a crucial component in safeguarding potable water from contamination. Used primarily in fire line sprinkler systems where it prevents the backflow of fire suppression materials into the potable water supply, its installation is typically mandated by local authorities in areas identified as non-health hazard continuous pressure applications. It has outside stem and yoke resilient seated gate valves and a gallons per minute meter that measures water to detect unauthorized water usage and ground leaks. The post indicator valve allows for easy visual confirmation if the valve is open or closed.
Features
- Post indicator valve
- Stainless steel for corrosion resistance
- Gallons per minute meter
- Protect against both backpressure and backsiphonage
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. It carries USC FCCCHR approval, which many jurisdictions accept as their sole approval list.
- 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. The bypass meter reads in GPM.
Specifications
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Type: Double Check
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Size: 4"
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Inlet Size: 4"
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Outlet Size: 4"
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Seat / Seal Material: Silicone
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Max Pressure (psi): 175
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Application: Fire Protection
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Backflow Protection: Both
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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: 757DCDA-OSYXPIV-GPM 4
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Temperature: 33°F to 140°F
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Certifications: UL, FM, USC
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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: Yes
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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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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: GPM
