The sealing surface forms of neck flat welding flanges are:

Raised surface (RF), concave surface (FM), convex surface (M), tenon surface (T), groove surface (G), full surface (FF).

The diameter range of the flat welding flange with neck: DN10~DN600

Advantages: Flat-welded flanges with necks are also flat-welded flanges, because they have a short neck, which increases the strength of the flange and improves the load-bearing strength of the flange. So it can be used on higher pressure pipelines.

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