Mechanical devices in the nature of flow meters, sensors, valves, and microcontrollers, and mechanical systems comprised of flow meters, sensors, valves, and microcontrollers, for monitoring and controlling the flow of beverages in dispensing systems, specifically draft beer; foam-detection equipment, comprised of sensors for detecting foam and monitoring carbonation and line pressure, automatic valves, and sight glasses, that can be integrated into beverage lines to automatically stop flow d...