Potter Amseco VSR-S Waterflow Alarm Switch for Small Pipe

The Potter Amseco VSR-S (VSRS) is a vane-type waterflow alarm switch with adjustable retard designed for wet fire sprinkler systems using 1-inch, 1-1/4-inch, 1-1/2-inch, or 2-inch piping. Featuring two SPDT Form C contacts, a 0-90-second pneumatic time delay, and a 300 PSI pressure rating, it detects sustained sprinkler waterflow of 10 GPM (38 LPM) or greater. The switch includes 12 interchangeable paddles, a 1-inch NPT threaded fitting, and a NEMA 4/IP54 weather-resistant enclosure for compatible indoor and outdoor installations.

Potter VSR-S Vane-Type Waterflow Alarm Switch for 1-2 Inch Sprinkler Pipes

The Potter Amseco VSR-S Vane-Type Waterflow Alarm Switch is a mechanical sprinkler flow detection device engineered to monitor water movement in wet-pipe fire sprinkler systems. Designed for 1-inch, 1-1/4-inch, 1-1/2-inch, and 2-inch piping, the VSR-S provides an electrical alarm signal when sustained waterflow indicates sprinkler system operation. Its internal paddle extends into the waterway and responds to moving water, mechanically actuating the switch assembly after the selected time delay expires. The device is suitable for residential sprinkler installations, small commercial fire protection systems, and sectional waterflow monitoring within larger sprinkler networks. Compatible applications include manufacturer-approved CPVC, copper, brass, and iron piping configurations, making the VSR-S a flexible monitoring component for properly designed wet sprinkler installations.

The VSR-S incorporates two independent single-pole, double-throw (SPDT) Form C snap-action switches that provide separate electrical outputs for fire alarm monitoring and auxiliary notification equipment. Each contact set is rated for 10A at 125/250VAC or 2A at 30VDC resistive, with a minimum switching current of 10mA at 24VDC. The flow detection mechanism activates when water movement reaches 10 gallons per minute (38 liters per minute) and continues long enough to overcome the adjustable pneumatic retard. Its 0-90-second field-adjustable delay helps reduce unwanted alarms caused by temporary pressure fluctuations, trapped air, or brief water surges. The pneumatic retard automatically resets when waterflow stops, allowing the detector to respond to subsequent sustained flow conditions without requiring manual reset.

Designed for installation in wet fire sprinkler piping, the Potter VSR-S features a 1-inch NPT threaded connection that installs into a properly sized and approved tee fitting. The unit includes 12 interchangeable paddles for different pipe sizes and approved threaded, sweat, and CPVC tee configurations. Proper paddle selection ensures that the vane responds correctly to water movement without binding against the interior of the pipe fitting. The device can be installed on appropriately configured horizontal or vertical piping, with horizontal installations requiring positioning on the upper side of the pipe. Potter specifies a minimum clearance of 6 inches from fittings that change waterflow direction and 24 inches from valves or drains. These installation requirements help maintain reliable operation and prevent turbulence or mechanical interference from affecting alarm response.

The Potter VSR-S features a NEMA 4/IP54-rated weather-resistant enclosure consisting of a high-impact composite cover and die-cast aluminum base. Its factory-installed gasket and tamper-resistant cover screws help protect the internal switches and pneumatic retard assembly from environmental exposure and unauthorized access. Two 1/2-inch conduit connections provide separate wiring compartments suitable for circuits operating at different voltages, while an optional cover tamper switch enables monitoring of enclosure removal. The VSR-S is rated for 300 PSI (20.68 bar) service pressure, a maximum water surge velocity of 18 feet per second (5.5 m/s), and ambient temperatures from 40 F to 120 F (4.5 C to 49 C). Manufacturer documentation identifies UL/cUL listing and applications associated with NFPA 13, NFPA 13D, NFPA 13R, and NFPA 72, subject to approved system design and installation. Assembled in the United States and backed by a five-year limited manufacturer warranty, the VSR-S provides supervised waterflow signaling for compatible residential and commercial fire sprinkler systems.