LWN flange (Long Weld Neck flange) also known as nozzle flange or straight hub welding flange. It is constructed by 2 sections: the upper section is a heavy-wall barrel and the lower section is a disc, like plate flange.

The long weld neck flange is an integral self-reinforcing flange connection majorly applied to the construction of pressure vessel.  The long weld neck flange was designed to be used in the place of a weld neck flange and piece of pipe for a bolt up connection to the vessel, this design reduced the pressure on the neck and transferred it to the base where it connected to the vessel.

The long weld neck flange is the most common of self-reinforced nozzle designs.  Typically the longer the nominal size and pressure, the longer of the length of the neck, the standard bore for the LWN flange is the same as the pipe size but can be ordered to any size bore.

PENGTONG sell long weld neck flange in grade A-105, ST37, P245 GH,  S235 JRG2, A182 F304/304L and A182 F316/316L. Please email or call us for your flange quote!