The Potter VSR-F series is a vane-type water flow switch designed for use on wet sprinkler systems. It serves as the industry standard for flow switches in fire protection, providing reliable waterflow detection for alarm signaling. The VSR-F can be mounted on horizontal or vertical pipe and may also be used as a sectional waterflow detector on large systems.

Working Principle

The VSR-F contains two single pole, double throw (SPDT), snap action switches and an adjustable, instantly recycling pneumatic retard. The switches are actuated when a flow of 10 gallons per minute (38 Lpm) or more occurs downstream of the device. The flow condition must exist for a period of time necessary to overcome the selected retard period, preventing false alarms from momentary pressure surges.

Key Features

• Vane Type Design: Proven paddle-type mechanism for reliable waterflow detection in fire sprinkler systems.
• Two SPDT Switches: Provides two sets of Form C contacts rated at 10A @ 125/250VAC, allowing connection to multiple alarm devices (e.g., local bell and remote signaling unit).
• Adjustable Pneumatic Retard: Field-adjustable 0-90 second delay prevents false alarms from water surges or pressure fluctuations.
• NEMA 4/IP54 Enclosure: Suitable for indoor or outdoor use with factory-installed gasket and die-cast housing.
• Wide Pipe Compatibility: UL Listed and FM Approved for use on steel pipe schedules 5 through 40, sizes 2" to 6", and schedules 10 through 40, sizes 2" to 8".
• Tamper-Resistant Cover: Cover held in place with tamper-resistant screws requiring special key for removal; optional cover tamper switch available.
• Hazardous Location Version: VSR-FEX model available for use on wet sprinkler systems located in hazardous locations.
• Non-Corrosive Sleeve: Factory installed in saddle for enhanced durability.

Technical Specifications

• Maximum Surge: 18 FPS (5.5 m/s)
• Minimum Flow to Activate: 10 GPM (38 LPM)
• Contact Rating (Minimum): 10 mA @ 24 VDC
• Conduit Entrances: Two 1/2" knockouts for conduit. Individual switch compartments suitable for dissimilar voltages.
• Environmental: NEMA 4/IP54 Rated Enclosure suitable for indoor or outdoor use with factory installed gasket and die-cast housing when used with appropriate conduit fitting.
• Listings and Approvals: UL, CUL, CSFM Listed, FM Approved, LPCB Approved. For CE Marked (EN12259-5) / VdS Approved model, use VSR-EU.
• Service Use: Automatic Sprinkler (NFPA-13), One or two family dwelling (NFPA-13D), Residential occupancy up to four stories (NFPA-13R), National Fire Alarm Code (NFPA-72).

Applications

The VSR-F series is ideal for flow/no-flow detection and alarm signaling in wet pipe fire sprinkler systems for commercial, industrial, and residential buildings. It is compatible with steel pipe schedules 5 through 40, sizes 2" through 8".

Ordering Information

Models are available for various pipe sizes including VSR-F-2 (2"), VSR-F-2-1/2 (2-1/2"), VSR-F-3 (3"), VSR-F-4 (4"), VSR-F-6 (6"), and VSR-F-8 (8"). For hazardous locations, order VSR-FEX series.