... , Japanese standard, the Russian standard.Pipe flange standard system on the international 2,The international pipe flange standard system 1 ... Joint type with neck threaded, Integral type and Blind flange. d, flange sealing surface: flat, raised face,male and female, ... socket welding, threaded connection, loose, butt weld and blind flange d, Flange sealing surface: raised face, male and female, tongue ...