Designed for installation in pipe lines from 1-1/4” and up, McDonnell & Miller standard FS7-4W series switches sense liquid flow in either direction to monitor flow/no-flow conditions. They are supplied in two paddle lengths, the paddle being 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 thereby activating the switch.
