McDonnell & Miller 120611 Model FS251 – Snap Liquid Flow Switch
McDonnell & Miller model number FS251 is a 120 volt, single pole, double throw, snap liquid flow switch for starting and stopping electrical equipment such as alarms, motors, and automatic burners. This switch features a sensitivity adjustment screw for easy flow adjustment, 1″ MIP horizontal configuration, NEMA 1, a maximum temperature of 250°F, and a 160 psi operating pressure.