The new Model DFS 5.1 Doppler Flow Switch controls flow with a non-contacting ultrasonic sensor mounted on the outside of pipes ½ inch diameter or larger. It installs in minutes. No pipe drilling or cutting is required and there is no maintenance. The Greyline DFS 5.1 is designed for pump protection, valve control and flow/no-flow alarms. It is ideal to control wastewater, slurries, caustics, acids and "difficult" liquids. The water tight NEMA4X switch enclosure includes a 5 ampere DPDT control relay with adjustable ON and OFF set point controls, adjustable time delay, flow rate bargraph and relay status LED's. A sensor mounting kit is included with each switch and sensor cable can be extended up to 150 m.