Oxylance Oxygen Ball Valves, and Lever Valves, unlike most valves have been specifically designed for Oxygen. Most common ball valves use a Teflon seat to seal the stem of the valve. Our valves were designed with Viton O-rings on the stems instead of a single Teflon seal. All our valves can be rebuilt, and we stock the parts for rebuilding. Both the Ball Valve and the Lever Valve bodies are CNC machined from solid brass instead of a cast part.