The Model VSG is a flexible vane type of waterflow switch for use in wet pipe water mist systems where a low flow for alarm is required.  The unit may also be used as a sectional waterflow detector on large systems. The unit contains an output relay and an adjustable electronic retard. The relay is actuated when a flow of 3 gallons per minute (11,4 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.