Long Weld Neck Flanges are like weld neck flanges, except for the neck, which is extended and acts like a boring extension. Long weld neck flanges can be used in high pressure industrial applications, as well as high temperature situations.The Long Weld Neck Flange is constructed by two sections: the upper section is a heavy-wall barrel, whilst the lower section is a disc-like plate flange with all dimensions conforming to ASME B16.5 standard flanges.