Zurn Wilkins 350ASTDA Double Check Detector Assembly

Safeguard commercial, industrial, and residential fire protection systems against backpressure and backsiphonage with the 350ASTDA Double Check Detector Assembly. This assembly installs directly into supply lines to protect potable water infrastructure from contamination. Featuring dual independent check modules and a metered bypass system, it provides backflow prevention and detects leaks or unauthorized water use. Shutoff configuration varies by selected SKU: BFG options use grooved-end butterfly shutoff valves, while OSY options use OS&Y gate valves.

To ensure regulatory compliance and life safety performance, this assembly satisfies the requirements mandated by NFPA 13 and NFPA 25 standards for fire protection system installation and periodic testing. It carries essential third-party agency evaluations including UL and FM approvals alongside ASSE 1015 certification, verifying its performance for demanding installations.

Key Features & Construction

• Durable Body Construction: Built from corrosion-resistant high-grade stainless steel and fusion-bonded epoxy-coated ductile iron to extend service life in harsh environments.
• Dual Check Mechanisms: Utilizes two independent, spring-loaded check modules featuring high-strength glass-filled thermoplastics to create a redundant barrier against reverse flow.
• Integrated Monitoring & Control: Features a metered bypass system that detects low-flow demands, leaks, or unauthorized usage. Select grooved-end butterfly shutoffs (BFG) or OS&Y gate valves according to the exact variant SKU and required end connections.
• Simplified Maintenance: Incorporates accessible internal components and reversible EPDM elastomer seats that allow for servicing without removing the entire valve body from the line.
• Flexible Orientation: Supports both horizontal and vertical flow-up installation configurations to match job-site piping layouts.
• Operating Parameters: Handles maximum working pressures up to 175 PSI and water temperatures ranging from 33°F to 140°F.

Technical Specifications & Compliance Table

Contractors and facility managers must verify local Authority Having Jurisdiction (AHJ) requirements and consult the official Zurn specification sheet for complete engineering data and sizing guidelines prior to system installation.

Documentation: Download Manufacturer Technical Data & Cut Sheet (PDF)