Standard FS-550 switches sense liquid flow in either direction to monitor flow/no-flow conditions. They are supplied in two paddle lengths. The paddle is trimmed during installation to permit switch actuation at the desired flow rate. As flow increases in a pipe, the paddle of the switch pivots to move out of the liquid path, producing less than 3 psig (.21 bar) of pressure drop regardless of pipe size.
Using Gems™ Safe-Pak® Relays and Barriers, these switches provide automatic flow / no flow interlock and are intrinsically-safe without explosion-proof housing and piping.