CGA540 valve outlet and 3/4″ NGT inlet. DSW is one of leading suppliers in compressed gas valves. The extensive list of quality features and testing in each valve includes: Heavy-duty forged brass body Precisely machined internal components Unitized plug Pressure Relief Device (PRD) Metal-to-metal seal below bonnet threads Direct-drive stem design with optimized O-ring seal 100% helium leak tested Automated assembly and testing ensures exceptional quality.