All KPMI Black Diamond ® stainless steel valves are impregnated by a special German process to a depth of .002”, with a surface build up of .0002”. This “Black Diamond®” process improves wear properties, reduces friction, and provides resistance to corrosion and wear that is superior to chrome and nickel electrolysis plating. Black Diamond® Valves are light, strong, one-piece forgings with profiles that provide excellent flow characteristics.