We are offering weld neck flanges. This is designed to be joined to a piping system by butt welding, it is relatively expensive because of its long neck, but is 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 re- inforcement of the flange. The bore of the flange matches the bore of the pipe, reducing turbulence and erosion.