Abstract: In a flow switch provided for connection in a fluid pipeline, a metering piston or other flow sensor is provided for placement in a pipe in the path of fluid flow. Fluid pressure above a certain minimum will cause the sensor to move, permitting fluid flow and moving the end of a pivot arm. The pivot arm transmits motion, through a flexible rubber-on-dacron seal, to a mechanical linkage which operates an electric switch. Means are provided to adjust the pressure response of the flow sensor and to vary the travel distance of an actuating plunger relative to the electric switch. Improved bearing means are provided for transferring motion between the pivot arm and the mechanical linkage.