Welding Neck Flange

Manufacturers of steel flanges follow ansi b16.5 standards when designing or machining a flange. A long weld neck flange, or LWN,is considered a specialty flange because of its protruding neck.The neck extends from the flat surface of the flange and receives and guides the pipe into place— the neck serves as an extension of the boring.Tapering the neck provides extra reinforcement for use in high-pressure or extreme and fluctuating temperature applications.

Weld Neck Flanges are designed to be joined to a piping system by butt welding.Weld Neck Flanges are preferred for high stresses to the pipe, reducing stress applications. The neck, or hub, transmits stress concentration at the base of the flange. The gradual transition of thickness from the base of the hub to the wall thickness at the butt weld provides important reinforcement of the flange.