Description
Zurn Wilkins 1-975XL 1" RPZ Reduced Pressure Backflow Preventer
Product Overview
The Zurn Wilkins 1-975XL 1" backflow preventer is the 1-inch model in the proven Wilkins 975XL Series of reduced pressure principle assemblies. This compact bronze RPZ backflow preventer protects potable water supplies against backsiphonage and backpressure from contaminated water in high-hazard cross-connections.
Designed for commercial plumbing, irrigation, mechanical equipment and industrial water systems, the 1-975XL features a wye-pattern bronze body for a compact installation footprint and convenient in-line service access. Full-port ball valves, replaceable check components and an integrated relief valve help simplify testing, maintenance and repair.
Cast-bronze construction, stainless steel fasteners and springs, Noryl™ internal polymers, and silicone and Buna-N elastomers provide durable performance in demanding installations. The 1" model also provides increased flow capacity over the 3/4" assembly while maintaining the same compact, service-friendly design.
Key Features & Benefits
- 1" RPZ backflow preventer designed for high-hazard cross-connection protection
- Protects potable water supplies against both backsiphonage and backpressure
- Compact wye-pattern bronze body helps reduce required installation space
- Integrated relief valve provides reduced pressure principle protection
- Full-port QT ball valves included with the standard assembly
- 1" female NPT threaded inlet and outlet connections
- First and second check assemblies are accessible for in-line service
- Checks can be serviced without removing the relief valve or complete assembly from the pipeline
- Durable cast-bronze body with 300 Series stainless steel fasteners and springs
- Maximum working pressure of 175 PSI and water temperature up to 180°F
- ASSE® 1013 listed reduced pressure principle assembly
Why Choose the Zurn Wilkins 1-975XL 1" Backflow Preventer?
The Zurn Wilkins 975XL Series combines compact bronze construction with convenient in-line service access. Its wye-pattern configuration allows technicians to reach the first and second check assemblies without removing the relief valve or taking the complete backflow preventer out of the piping system.
The 1-975XL is the 1-inch configuration and is well suited to commercial, irrigation and mechanical systems requiring reduced pressure principle protection. Its integrated relief valve, threaded connections, high-temperature capability and established approval profile make it a practical choice for demanding installations.
The compact footprint also makes the 1" model practical for mechanical rooms, utility spaces and retrofit applications where serviceability and available installation space are important.
Zurn Wilkins 1-975XL at a Glance
- Model: 1-975XL
- Series: Wilkins 975XL
- Size: 1 inch (DN25)
- Type: RPZ / Reduced Pressure Principle Backflow Preventer
- Connections: 1" Female NPT
- Body: Cast Bronze
- Maximum Pressure: 175 PSI
- Maximum Temperature: 180°F
- Shut-Off Valves: Full-Port QT Ball Valves
- Application: High-hazard cross-connection protection
Typical Applications
The Zurn Wilkins 1-975XL 1" RPZ backflow preventer is designed to protect potable water supplies from high-hazard cross-connections serving non-potable systems and equipment. Typical applications include:
- Irrigation and sprinkler systems
- Boiler and HVAC make-up water connections
- Commercial plumbing systems
- Mechanical equipment connections
- Industrial process-water systems
- Laboratory and institutional equipment
- Water treatment equipment
- Other high-hazard non-potable applications
The Zurn Wilkins 975XL protects the potable water supply from a connected hazard; however, Zurn specifies the assembly for non-potable applications only. Final product selection and installation must comply with local plumbing codes, cross-connection-control requirements, and the authority having jurisdiction.
Engineering Specification
The Zurn Wilkins 1-975XL shall be a 1" reduced pressure principle backflow prevention assembly with full-port ball valves. The assembly shall be ASSE® Listed 1013 and rated for a maximum working water temperature of 180°F.
The main valve body and access covers shall be cast bronze conforming to ASTM B584. Seat rings and internal polymer components shall be Noryl™, seat-disc elastomers shall be silicone, and fasteners and springs shall be manufactured from 300 Series stainless steel.
The first and second check assemblies shall be accessible for in-line maintenance without removing the relief valve or complete assembly from the pipeline. Where installed indoors, an air-gap adapter shall be provided. The assembly shall be intended for non-potable applications and shall be Zurn Wilkins Model 1-975XL.
Product Specifications
| Specification | Details |
|---|---|
| Manufacturer | Zurn Wilkins |
| Model | 1-975XL |
| Series | 975XL |
| Assembly Type | Reduced Pressure Principle Assembly |
| Common Abbreviation | RP / RPZ |
| Nominal Size | 1" / DN25 |
| Shut-Off Valves | Full-Port QT Ball Valves |
| End Connections | Female NPT Threaded |
| Thread Standard | ANSI B1.20.1 |
| Maximum Working Pressure | 175 PSI / 12.1 bar |
| Maximum Working Temperature | 180°F / 82°C |
| Hydrostatic Test Pressure | 350 PSI / 24.1 bar |
| Main Body Material | Cast Bronze, ASTM B584 |
| Access Cover Material | Cast Bronze, ASTM B584 |
| Fasteners | 300 Series Stainless Steel |
| Springs | 300 Series Stainless Steel |
| Elastomers | Silicone and Buna-N |
| Internal Polymers | Noryl™ |
| Relief-Valve Discharge-Port Area | 0.63 sq. in. / 406 mm² |
| Application Classification | Non-Potable Applications Only |
| Order Number | 1-975XL |
Dimensions & Weight
| Dimension | Imperial | Metric |
|---|---|---|
| Overall Length with Ball Valves – A | 13" | 330 mm |
| Body Length – B | 7-3/4" | 197 mm |
| Dimension C | 2-1/8" | 54 mm |
| Dimension D | 3" | 76 mm |
| Dimension E | 3-1/2" | 89 mm |
| Dimension F | 5" | 127 mm |
| Overall Height – G | 17-3/8" | 441 mm |
| Approximate Weight | 14 lb | 6.4 kg |
| Order Number | 1-975XL | |
Dimensions and weights are approximate and do not include packaging.
Approximate Schedule 40 Pipe Capacity
| Pipe Velocity | Approximate Flow Capacity |
|---|---|
| 5 ft/sec | 13 GPM |
| 7.5 ft/sec | 20 GPM |
| 10 ft/sec | 27 GPM |
| 15 ft/sec | 40 GPM |
Published values represent approximate Schedule 40 pipe capacity and should not be interpreted as the certified rated flow of the backflow assembly.
Materials of Construction
| Component | Material |
|---|---|
| Main Valve Body | Cast Bronze, ASTM B584 |
| Access Covers | Cast Bronze, ASTM B584 |
| Fasteners | 300 Series Stainless Steel |
| Springs | 300 Series Stainless Steel |
| Elastomers | Silicone and Buna-N |
| Internal Polymers | Noryl™ |
Standards & Approvals
- ASSE® Listed 1013
- cUPC® Listed
- UL® Classified when supplied in qualifying configurations
- cUL® Classified
- CSA® Certified B64.4
- AWWA C511 compliant
- Approved by the Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California
- NYC MEA 425-89-M Volume 3
Approvals may vary by exact configuration, installation orientation and jurisdiction. Verify project-specific requirements before ordering.
Zurn 1-975XL Installation Tips
- Install the assembly in the direction of flow indicated on the valve body.
- Flush the piping before installation to help prevent debris from entering the check assemblies.
- Follow the manufacturer's installation instructions and all applicable plumbing and cross-connection-control requirements.
- Unless otherwise specified, position the assembly at least 12" (305 mm) and no more than 30" (762 mm) above an adequately sized drain.
- Provide sufficient clearance for testing, inspection and maintenance.
- Do not install the assembly where any portion of the unit may become submerged.
- Use an approved air-gap adapter for indoor installations.
- Provide freeze protection and a suitable enclosure for outdoor installations in cold climates.
- Keep the ball valves, test cocks, access covers and relief valve accessible.
- Provide drainage capable of accepting relief-valve discharge.
- Have the completed installation tested by a qualified or certified backflow tester as required by the authority having jurisdiction.
Compatible Zurn 975XL Accessories
- Zurn Model AG air gap
- Zurn Model SXL bronze Y-strainer
- Zurn repair kits
- Zurn Model XT thermal expansion tank
- Zurn Model 40XL2 soft-seated check valve
- Zurn Model 1260XL shock arrester
- QT-SET Quick Test Fitting Set
Accessories are sold separately unless expressly included in the product listing.
Zurn Wilkins 1-975XL Frequently Asked Questions
Is the Zurn 1-975XL the 1-inch version of the 975XL?
Yes. The Zurn Wilkins 1-975XL is the 1-inch (DN25) configuration of the Wilkins 975XL reduced pressure principle backflow preventer series.
Is the Wilkins 975XL an RPZ backflow preventer?
Yes. The Wilkins 975XL is a reduced pressure principle backflow prevention assembly, commonly referred to as an RP or RPZ backflow preventer.
What does the Zurn Wilkins 1-975XL protect against?
The 1-975XL protects the potable water supply from contamination caused by both backsiphonage and backpressure.
What size connections does the Zurn Wilkins 1-975XL use?
The 1-975XL uses 1-inch female NPT threaded inlet and outlet connections conforming to ANSI B1.20.1.
Where is the Zurn 1-975XL commonly used?
Typical applications include irrigation systems, commercial plumbing, boiler and HVAC make-up water connections, mechanical equipment and industrial water systems where reduced pressure principle protection is required.
Does the 1-975XL include a relief valve?
Yes. The 1-975XL is a complete reduced pressure principle assembly with an integrated relief valve for high-hazard cross-connection protection.
Is the 1-975XL intended for potable applications?
The assembly protects a potable water supply, but Zurn specifies the Model 975XL for non-potable applications only.
What shut-off valves are included with the 1-975XL?
The standard 1-975XL configuration includes full-port QT ball valves.
Can the Zurn 1-975XL be serviced in-line?
Yes. The first and second check assemblies can be accessed without removing the relief valve or complete assembly from the pipeline.
What is the maximum working pressure of the 1-975XL?
The maximum working water pressure is 175 PSI, or approximately 12.1 bar.
What is the maximum working temperature?
The maximum working water temperature is 180°F, or approximately 82°C.
Is an air gap required for the Zurn 975XL?
Zurn specifies an air-gap adapter for indoor installations. Local drainage and plumbing requirements must also be followed.
Does the 1-975XL require backflow testing?
Testing requirements are determined by the local authority having jurisdiction. Reduced pressure assemblies commonly require commissioning and recurring testing by a qualified backflow tester.
Zurn Wilkins 1-975XL Product Video
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