The weld neck flange is normally referred to as the high-hub flanges. It is designed to transfer and equally distribute stresses to the pipe, thereby reducing any concentration of high stress at the bottom of the flange after connections are made. The weld neck flange is the best-designed flange for butt welding because of its inherent strength. A long tapered hub and gradual transition of thickness in the region of the butt-weld joint adds reinforcement from the standpoint of strength and resistance to dishing. The smooth transition from the flange thickness to the pipe wall thickness effected by the taper is extremely beneficial under conditions of repeated bending caused by line expansion or other variable forces.