Designed for both indoor and outdoor use; Equipped with tamper resistant screws to prevent unauthorized entry. Two synchronized switches are enclosed in a durable terminal block. Terminals are easy to read and wire. Built-In mechanical time delay feature; minimizing the risk of false alarms due to pressure surges or air trapped in the system. Offers excellent performance during riser vibrations caused by large in-rushes of water. Designed and built for accuracy and repeatability. Sealed retard mechanism immune to dust and other contaminants Field-replaceable retard mechanism and SPDT switches Rugged, dual SPDT switches enclosed in a durable terminal block 100 percent synchronization activates both alarm panel and local bell Tamper-resistant cover screws
Manufacturer: SHIELD
Vendor: NAFFCO
505.00 (AED)
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The Model SD-WFD is a vane type waterflow swi tch for use on wet sprinkler system s. The water flow contains two single pole, double throw, snap action switches and an adjustable, instantly recycling pneumatic retard. Vane-type waterflow detectors shall be installed on system piping as designated on the drawing and/or as specified herein. Detectors shall have sensitivity in the range of 4 to 10 gallons per minute and a static pressure rating of 450 psi for 2˝–8˝ pipes. The flow condition must exist for a period of time necessary to overcome the selected retard period that is field adjustable. 

The delay mechanism shall be a sealed mechanical pneumatic unit with visual indication of actuation. The actuation mechanism shall include a polyethylene vane inserted through a hole in the pipe and connected by a mechanical linkage to the delay mechanism. Outputs shall consist of dual SPDT switches. Two conduit entrances for standard fittings of commonly used electrical conduit shall be provided on the detectors.