System Sensor WFD20 | Waterflow Detector for 2″ Steel Sprinkler Pipe | NEMA 4 Rated – UL/FM Approved

The System Sensor WFD20 Waterflow Detector is a high-performance vane-type waterflow detector designed to monitor water movement in 2-inch wet pipe fire sprinkler systems. Engineered for dependable fire alarm activation, the WFD20 features a rugged NEMA 4-rated enclosure, dual synchronized SPDT (Form C) contacts, and an adjustable pneumatic retard mechanism that minimizes nuisance alarms caused by pressure surges or trapped air within the sprinkler piping.

Designed for both indoor and outdoor installations, the WFD20 mounts directly to 2-inch Schedule 7 through Schedule 40 steel sprinkler pipe and is ideal for commercial, industrial, institutional, and residential fire sprinkler systems installed in accordance with NFPA 13, NFPA 13D, NFPA 13R, and NFPA 72. The detector features a corrosion-resistant enclosure, wire-ready terminals, visual switch activation, audible switch activation, and a field-replaceable timer/switch assembly for simplified installation and long-term reliability.

Whether you’re installing a new fire sprinkler system or replacing an existing waterflow switch, the WFD20 delivers dependable waterflow detection while meeting the stringent requirements of today’s fire protection industry.

Technical Specifications

• Manufacturer: System Sensor
• Model: WFD20
• Product Type: Waterflow Detector
• Detection Method: Mechanical Vane-Type
• Compatible Pipe Size: 2″
• Compatible Pipe Schedule: Schedule 7–40 Steel Pipe
• Required Hole Size: 1¼”
• Static Pressure Rating: 450 PSI
• Flow Threshold: 4–10 GPM
• Maximum Water Surge: 18 Feet Per Second
• Operating Temperature: 32°F to 150°F (0°C to 66°C)
• Enclosure Rating: NEMA 4
• Contacts: Two SPDT (Form C)
• Electrical Rating: 10A @ 125/250 VAC, 2.5A @ 6/12/24 VDC
• Conduit Entrances: Two ½” conduit openings
• Compatible Systems: Wet Pipe Fire Sprinkler Systems
• NFPA Standards: NFPA 13, NFPA 13D, NFPA 13R, NFPA 72
• Approvals: UL Listed, ULC Listed, FM Approved
• Warranty: 3 Years

Key Features

• Designed for 2″ steel wet pipe fire sprinkler systems
• Vane-type waterflow detector
• Rugged NEMA 4 enclosure
• Suitable for indoor and outdoor installations
• Adjustable pneumatic mechanical retard mechanism
• Minimizes nuisance alarms from water surges
• Visual switch activation indicator
• Audible switch activation (73 dBA)
• Dual SPDT (Form C) synchronized contacts
• Wire-ready terminal block for easy wiring
• Field-replaceable timer and switch assembly
• Corrosion-resistant lightweight housing
• Tamper-resistant cover screws
• Two ½” conduit entrances
• Compatible with Schedule 7–40 steel pipe
• UL Listed
• ULC Listed
• FM Approved
• 3-Year Manufacturer Warranty

Applications

• Commercial Fire Sprinkler Systems
• Industrial Fire Protection Systems
• Warehouses
• Manufacturing Facilities
• Office Buildings
• Hotels
• Schools
• Hospitals
• Apartment Buildings
• Condominium Buildings
• Institutional Buildings
• Wet Pipe Fire Sprinkler Systems