6 Manifolds of metal; metal pipes; screw connections in the nature of metal pipe connectors; compressed gas fittings made of metal, namely bushings of metal; metal pipe connectors and metal clamps; valves of metal, other than parts of machines and apparatus, namely, manually operated metal valves for filling cylinders and tanks with gasses or air; valves made of metal other than parts of machines for liquids, gases and air; valves of metal, other than parts of machines, namely, check valves, excess flow valves and pressure relief valves for liquids, gases and air; non-automatic fueling nozzles; non-automatic fueling nozzles for liquefied petroleum, gases, cryogenic liquids and fuel; all of the foregoing for use in connection with liquefied petroleum, gases, cryogenic liquids and fuels