Flow meters; Flow switches for monitoring and controlling the flow of gases or liquids; Automatic liquid-flow control machines and instruments; Automatic valves for controlling flow rates of gases liquids and slurries; Control valves for regulating the flow of gases and liquids; Gas flow meters; Gas flow monitors; Gas appliance alarm timer for detecting and alerting the presence of gas flow after a prescribed period of time; Metering orifices, namely, orifice plates for metering or controllin...