1, according to the chemical industry (HG) specification: integral flange (IF), threaded flange (Th), plate (PL) flat welding flange, butt welding neck flange (WN), with flat welding neck flange, socket welding flange (SO) (SW), the butt welding ring loose flange (PJ/SE), flat welding ring loose flange (PJ/RJ), lining flange cover (BL (S)), flange cover (BL) [2].
2, according to the petrochemical industry standards (SH) points: threaded flange (PT), butt welding flange (WN), flat welding flange (SO), socket welding flange (SW), loose flange (LJ), flange cover (not table).
3, according to the mechanical industry standards (JB) points: integral flange, butt welding flange, plate flat welding flange, butt welding plate loose flange rings, flat welding ring plate loose flange, flange ring plate loose flange, flange cover.
4, according to country standard (GB) : integral flange, threaded flange, butt welding flange, with flat welding neck flange, socket welding neck flange, butt welding band neck loose flange, plate, flat welding flange, butt welding plate loose flange rings, flat welding ring plate loose flange, flange ring plate loose flange, flange cover.
