Flange type introduction

There are many types of flanges, which is a bit confusing. Today we will introduce the types of flanges so that everyone can know more about the types of flanges.
Classified by material:
20# A105 Q235A 12CrMoV16MnR 15CrMo 18-8 321304 304L 316 316L etc. According to the sealing surface form:
Flat surface (FF), raised surface (RF), convex surface (M), concave surface (F),
Concave-convex surface (MF), tongue surface (T), groove surface (G), tongue and groove surface (TG), ring connection surface (RJ)
According to national standards:
Integral flange, threaded flange, butt welding flange, flat-neck welding flange
Socket welding flange with neck, butt welding ring with neck loose flange, plate flat welding flange, butt weld ring plate loose flange, flat weld ring plate, loose flange, flange ring plate loose flange method Flange
According to chemical industry standards, it is divided into:
Integral flange (IF), threaded flange (Th), plate flat welding flange (PL), butt welding flange with diameter (WN),
Neck flat welding flange (SO), socket welding flange (SW), butt welding ring loose flange (PJ/SE), flat welding ring loose flange (PJ/RJ), lining flange cover ( BL (S)), flange cover (BL)
According to the petrochemical industry standards:
Threaded flange (PT), butt welding flange (WN), flat welding flange (PL), socket welding flange (Sw), loose flange (LJ), flange cover (BL)
According to machinery industry standards, it is divided into:
Integral flanges, butt welding flanges, plate flat welding flanges, butt welding ring plate loose flanges, flat welding ring plate loose flanges, flanged ring plate loose flanges, flange covers