Classification of weld neck flange
Long weld neck Flange
Long WN flange looks like the typical welding neck flange, but is considered to be elongated. It’s usually used as a nozzle for a column or barrel. You can also choose between the Equal LWN Barrel and LWN Heavy Barrel, which have a thick wall and their own shape.
Reducing Weld Neck Flange
It is also called reducing welding neck flange, because the flange neck has a reducing diameter that to weld to a smaller diameter pipe.
NW Long Weld Neck Flanges
This flange type is regarded as high-hub flanges, which were created so stress could be transferred to the pipe and decreasing the stress concentration at the bottom of the flange.