... Flange is a mechanical part which used for connecting pipe.Flange Type: Welded flange, Welding neck flange, Male and female ... public diameter: 6 ~ 4000mm c, Flange structure type: welding, socket welding, threaded connection, loose, butt weld and blind flange d, Flange ... and groove, metal rings connected surface 3, Chinese steel pipe flanges National Standards System GB 1) Nominal pressure: 0.25Mpa ...