Description
Zurn Wilkins 10-350AOSY 10" Double Check Valve Assembly
The Zurn Wilkins 10-350AOSY is a lead-free 10-inch Double Check Valve Assembly designed to protect potable water systems against backsiphonage and backpressure involving polluted water in non-health hazard applications. This large-diameter commercial backflow preventer includes full-port OS&Y gate valves, ANSI Class 125 flanged connections, an epoxy-coated ductile iron body and serviceable Compound Check® modules.
Product Overview
The Zurn Wilkins 10-350AOSY provides dependable backflow protection for large commercial, industrial, institutional and municipal potable water systems. It is intended for applications where polluted water could enter the potable water supply but where a potential health hazard does not exist.
The assembly features a heavy-duty ductile iron main body and access covers protected by an FDA-approved electrostatic epoxy coating. Its full-port OS&Y gate valves provide positive shutoff and a clear visual indication of valve position.
The Compound Check® design helps maintain low pressure loss across the assembly, while the internal check modules remain accessible for service without removing the complete valve body from the pipeline. Stainless steel internal components, NSF-listed NORYL™ check components and FDA-approved elastomers provide durability and corrosion resistance.
With an approximate assembled weight of 1,024 lb (464 kg) in the flanged OS&Y configuration, the 10-350AOSY is engineered for large-diameter commercial and municipal installations requiring substantial flow capacity and dependable backflow protection.
Features & Benefits
- ✓ Lead-Free Construction: Certified to NSF/ANSI 372 for potable water applications requiring lead-free components.
- ✓ 10-Inch Large-Diameter Design: Engineered for high-capacity commercial, industrial and municipal water systems.
- ✓ Compound Check® Technology: Provides reliable backflow protection while helping minimize pressure loss.
- ✓ Full-Port OS&Y Gate Valves: Provide positive shutoff and visible valve-position indication.
- ✓ Epoxy-Coated Ductile Iron Body: Delivers strength, corrosion resistance and long service life.
- ✓ In-Line Serviceability: Internal check components can be accessed without removing the complete assembly from the pipeline.
- ✓ Stainless Steel Internals: 300 Series stainless steel components resist corrosion in demanding installations.
- ✓ NSF-Listed NORYL™ Components: Durable engineered check components are suitable for potable water service.
- ✓ ANSI Class 125 Flanged Connections: Designed for secure connection to large commercial piping systems.
- ✓ Horizontal or Vertical Installation: Approved in either orientation when installed in accordance with applicable codes.
- ✓ 175 psi Working Pressure: Suitable for demanding commercial water distribution systems.
- ✓ Factory-Assembled Configuration: Supplied with test cocks and flanged OS&Y shutoff valves.
Product Applications
- Large commercial buildings
- Municipal water distribution systems
- Industrial facilities
- Institutional campuses
- Hospitals and healthcare facilities
- Universities and school districts
- Large irrigation systems
- Fire protection water services where approved
- Mechanical equipment rooms
- Large potable water service entrances
Ideal For
- Commercial plumbing contractors
- Mechanical contractors
- Municipal infrastructure projects
- Consulting engineers
- Industrial plant operators
- Institutional facility managers
- Large-diameter replacement installations
- Lead-free potable water systems
What's Included
- Zurn Wilkins 10-350A Double Check Valve Assembly
- Flanged OS&Y inlet gate valve
- Flanged OS&Y outlet gate valve
- Dual Compound Check® modules
- Factory-installed test cocks
- ANSI Class 125 flanged connections
- Factory-applied electrostatic epoxy coating
Certifications & Compliance
- ✓ ASSE 1015 Listed
- ✓ AWWA C510 Compliant with Gate Valves
- ✓ AWWA C550 Compliant
- ✓ IAPMO Listed
- ✓ NSF/ANSI 372 Certified
- ✓ NSF Standard 61, Annex G Listed
- ✓ CSA Certified
- ✓ UL Classified
- ✓ C-UL Classified
- ✓ FM Approved
- ✓ Approved by the USC Foundation for Cross-Connection Control and Hydraulic Research
Specifications
| Specification | Details |
| Brand | Zurn Wilkins |
| Series | Model 350A |
| Part Number | 10-350AOSY |
| Product Type | Double Check Valve Assembly |
| Nominal Size | 10 in (250 mm) |
| Shutoff Valves | Flanged OS&Y Gate Valves |
| End Connections | ANSI B16.1 Class 125 Flanged |
| Main Body Material | Ductile Iron, ASTM A536 Grade 4 |
| Access Cover Material | Ductile Iron, ASTM A536 Grade 4 |
| Body Coating | FDA-Approved Electrostatic Epoxy Finish |
| Internal Components | 300 Series Stainless Steel and NSF-Listed NORYL™ |
| Fasteners and Springs | 300 Series Stainless Steel |
| Seal Ring | FDA-Approved EPDM |
| O-Ring | FDA-Approved Buna-N Nitrile |
| Maximum Working Pressure | 175 psi (12.1 bar) |
| Maximum Water Temperature | 140°F (60°C) |
| Hydrostatic Test Pressure | 350 psi (24.1 bar) |
| Installation Orientation | Horizontal or Vertical |
| Approximate OS&Y Assembly Weight | 1,024 lb (464 kg) |
| Lead-Free Compliance | NSF/ANSI 372 |
Approximate Dimensions
| Dimension | Measurement |
| A — Body Assembly Length | 64-5/8 in (1,641 mm) |
| B — Body Length Less Gate Valves | 38-1/2 in (978 mm) |
| C | 10 in (254 mm) |
| D | 12 in (305 mm) |
| E — OS&Y Valve Open | 45-5/8 in (1,159 mm) |
| E — OS&Y Valve Closed | 34-3/4 in (883 mm) |
| F | 8-1/2 in (216 mm) |
| G — Overall Length with Gate Valves | 94-3/8 in (2,397 mm) |
Schedule 40 Pipe Capacity Reference
| Pipe Velocity | Reference Flow |
| 5 ft/sec | 1,229 GPM |
| 7.5 ft/sec | 1,843 GPM |
| 10 ft/sec | 2,458 GPM |
| 15 ft/sec | 3,687 GPM |
Flow values are Schedule 40 pipe-capacity references based on velocity and are not a substitute for engineering calculations or the manufacturer’s pressure-loss curve.
Installation Tips
- Confirm that a Double Check Valve Assembly is suitable for the application and degree of hazard.
- Install in accordance with all applicable plumbing, fire protection and cross-connection control requirements.
- Unless otherwise specified, mount the assembly at least 12 inches (305 mm) and no more than 30 inches (762 mm) above an adequate drain.
- Provide sufficient side and overhead clearance for testing, inspection and maintenance.
- Install the assembly so that no portion of the unit can become submerged.
- Flush upstream piping before installation to remove debris.
- Provide engineered supports for the assembly and adjacent piping. The OS&Y assembly weighs approximately 1,024 lb (464 kg).
- Do not use the adjoining pipe or flanges as the sole means of supporting the assembly.
- Verify the direction-of-flow arrow before tightening flange connections.
- Arrange for commissioning and testing by a qualified backflow tester where required.
Frequently Asked Questions
What is the Zurn Wilkins 10-350AOSY used for?
It protects potable water systems against backpressure and backsiphonage involving polluted water where a potential health hazard does not exist.
Is the 10-350AOSY lead-free?
Yes. It is certified to NSF/ANSI 372 for lead-free potable water applications.
What does OS&Y mean?
OS&Y means Open Stem and Yoke. The rising stem provides a visible indication of whether each gate valve is open or closed.
What type of connections does the assembly use?
The 10-350AOSY uses ANSI B16.1 Class 125 flanged connections.
What is the maximum working pressure?
The maximum working water pressure is 175 psi (12.1 bar).
What is the maximum operating temperature?
The maximum working water temperature is 140°F (60°C).
How much does the 10-350AOSY weigh?
The 10-inch assembly with flanged OS&Y gate valves weighs approximately 1,024 lb (464 kg), excluding packaging.
Can it be installed vertically?
Yes. The Model 350A is listed for horizontal and vertical installation when installed in accordance with local codes and approval requirements.
Can the checks be serviced without removing the complete valve?
Yes. The internal check assemblies are accessible for maintenance without removing the main device from the pipeline.
Is NYC MEA approval included for the 10-inch size?
No. The manufacturer lists NYC MEA 220-04-M Vol. 2 approval only for sizes 2-1/2 inches through 8 inches.
Why Buy From MasterBuilder Mercantile
MasterBuilder Mercantile supplies genuine Zurn Wilkins commercial plumbing products for contractors, engineers, facility managers and infrastructure projects. Our team can assist with product selection, replacement assemblies, technical documentation and compatible repair components.
- ✓ Genuine Zurn Wilkins products
- ✓ Commercial plumbing product expertise
- ✓ Support for large-diameter and project-based orders
- ✓ Shipping throughout Canada and the United States
- ✓ Access to repair kits and replacement components
Recommended Related Products
- Zurn Wilkins Model 350A repair kits
- Replacement Compound Check® modules
- Zurn Wilkins OSY-40 gate valve tamper switches
- Commercial wye strainers
- Backflow test equipment
- Large-diameter pipe supports
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