JIS B2220 (SOH) neck flange

Neck flanges are the same as plate flat welded flanges, but also extend steel pipes and pipe fittings into the flange to connect with equipment or pipelines through fillet welds.

The sealing surface forms include raised surface (RF), concave surface (FM), convex surface (M), tenon surface (T), groove surface (G), full surface (FF), ring connection surface (RJ).