shut off valves: 1,copper and stainless steel materials, 2,OEM/ODM service; 3,at most 3 gases available. Description:1,Material: copper ... and zinc-plated steel and welded by silver;2,Full-port and ball-type (double seal) valve with ... requires only one quarter turn of the whole opening or closing;5,The valve is brazed,cleaned for oxygen service and pressure tested and ...