Valves and related accessory components for gas cylinders (bottles). Includes cylinder main valves, regulator connection valves, safety valves, check valves, pressure gauges, gas leak detectors, valve caps, protective covers, etc. Provides safe opening/closing, flow control, and pressure monitoring for various industrial gas cylinders including oxygen/acetylene cylinders for welding/cutting work, nitrogen/argon cylinders for inert gas applications, and standard gas cylinders for analysis. Features pressure-resistant specifications compliant with High Pressure Gas Safety Act, including consumable parts requiring periodic inspection and replacement. Essential component group for ensuring safety of gas supply systems in manufacturing facilities.